ATTACHMENT 2

EAGLE CONSERVATION PLAN/BIRD CONSERVATION STRATEGY 

(ECP/BCS)
Mohave County Wind Farm 

Eagle Conservation Plan and 

Bird Conservation Strategy 

Prepared for 

BP Wind Energy North America Inc. 

Prepared by 

1750 SW Harbor Way, Suite 400 

Portland, OR 97201 

December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

TABLE OF CONTENTS
 

1 INTRODUCTION.................................................................................................................1
 

1.1 Background Information...............................................................................................1
 

1.2 Project Description ......................................................................................................5
 

1.3 Environmental Setting..................................................................................................9
 

1.4 Regulatory Framework ................................................................................................9
 

1.4.1 Migratory Bird Treaty Act..................................................................................9
 

1.4.2 Bald and Golden Eagle Protection Act ...........................................................10
 

1.4.3 BLM Instruction Memorandum No. 2010-156.................................................10
 

1.4.4 National Environmental Policy Act..................................................................10
 

1.4.5 Memoranda of Understanding between BLM and AZGFD..............................11
 

1.4.6 Arizona State Statutes ...................................................................................11
 

2 MONITORING AND SURVEYING TO DATE ....................................................................11
 

2.1 Bird Use Survey Methods ..........................................................................................11
 

2.1.1 Golden Eagle Results ....................................................................................15
 

2.1.2 Non-eagle Bird Species Results.....................................................................16
 

2.1.3 Sensitive Species...........................................................................................17
 

2.2 Songbird Migration Surveys.......................................................................................17
 

2.3 Golden Eagle Nest Surveys.......................................................................................20
 

2.3.1 2011 Golden Eagle Nest Survey Results .......................................................24
 

2.3.2 2011 Raptor Nests .........................................................................................24
 

2.3.3 2012 Golden Eagle Nest Survey Results .......................................................24
 

3 RISK ASSESSMENT ........................................................................................................28
 

3.1 Collision.....................................................................................................................28
 

3.1.1 Golden Eagles ...............................................................................................28
 

3.1.2 California Condor ...........................................................................................38
 

3.1.3 Other Non-eagle Bird Species........................................................................38
 

3.2 Electrocution..............................................................................................................47
 

3.3 Disturbance/Displacement.........................................................................................47
 

3.3.1 Golden Eagles ...............................................................................................47
 

3.3.2 Non-eagle Bird Species .................................................................................48
 

3.4 Habitat Fragmentation ...............................................................................................49
 

4 PROJECT PLANNING AND DESIGN MEASURES...........................................................49
 

5 CONSTRUCTION PHASE MEASURES............................................................................54
 

6 OPERATIONAL PHASE MEASURES...............................................................................56
 

7 POST-CONSTRUCTION FATALITY MONITORING .........................................................58
 

7.1 Initial Post-construction Fatality Monitoring................................................................59
 

7.2 Long-term Fatality Monitoring ....................................................................................59
 

7.3 Responsive Monitoring ..............................................................................................60
 

7.4 Eagle Behavioral Monitoring......................................................................................60
 

7.5 Wildlife Incident Monitoring System ...........................................................................61
 

7.5.1 Training..........................................................................................................61
 

7.5.2 Reporting .......................................................................................................61
 

7.6 Standardized Post-construction Fatality Monitoring ...................................................61
 

7.6.1 Technical Approach .......................................................................................61
 

7.6.2 Standardized Carcass Searches – Non-eagle bird species............................62
 

7.6.3 Standardized Carcass Searches – Eagles .....................................................64
 

7.6.4 Carcass Persistence Trials.............................................................................65
 

i December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

7.6.5	 Searcher Efficiency Trials...............................................................................67
 

7.6.6	 Fatality Rate Estimation .................................................................................67
 

8 MITIGATION AND ADAPTIVE MANAGEMENT ................................................................69
 

8.1 Identification of Compensatory Mitigation Approach ..................................................69
 

8.1.1	 Evidence for Eagle Fatalities Due to Vehicle Collisions..................................69
 

8.1.2	 Existing Information on Vehicle and Wildlife Collisions...................................71
 

8.2 Overview of Carcass Search/Removal as Compensatory Mitigation..........................73
 

8.3 Implementing Mechanisms ........................................................................................74
 

8.4 Bottom-up and Top-down Approaches for Mitigation .................................................74
 

8.5 Bottom-up Approach for Mitigation.............................................................................74
 

8.5.1	 Step 1: Determine Where Mitigation Efforts Should Be Targeted Within
 

Arizona ..........................................................................................................75
 

8.5.2	 Step 2: Evaluate the Annual Rate of Carcass Occurrence .............................78
 

8.5.3	 Step 3: Calculate the Number of Carcasses Available for Eagles per 100
 

miles of road..................................................................................................79
 

8.5.4	 Step 4: Calculate the Percentage of Carcasses Used by Golden Eagles .......79
 

8.5.5	 Step 5: Calculate the Number of Eagles Per Carcass ....................................80
 

8.5.6	 Step 6: Calculate the Number of Eagles Using Carcasses.............................81
 

8.5.7	 Step 7: Evaluate the Percentage of Eagles Involved in a Vehicle Collision
 

While Feeding on Carcasses.........................................................................81
 

8.5.8	 Step 8: Calculate the Number of Vehicle-Eagle Collisions per Year in the
 

Absence of Carcass Search/Removal ...........................................................81
 

8.5.9	 Step 9: How Many Miles of Roads Will Have Carcass Search/Removal.........82
 

8.6 Top-down Approach for Mitigation .............................................................................82
 

8.6.1	 Step 1: Estimate the Number of Golden Eagles Killed by Vehicle Collision
 

in Arizona ......................................................................................................83
 

8.6.2	 Step 2: Estimate the Total Mileage of Roads within Habitat Suitable for
 

Golden Eagles...............................................................................................86
 

8.6.3	 Step 3: Calculate the Number of Road Miles for Carcass Search/Removal
 

to Offset the Loss of One Golden Eagle.........................................................87
 

8.7 Comparison of the Bottom-Up and Top-Down Approaches........................................87
 

8.8 Implementation of the Roadside Carcass Search/Removal Program.........................89
 

8.9 Operational Mitigation and Adaptive Management for Eagles....................................91
 

8.9.1	 Adaptive Management of Curtailment Program..............................................92
 

8.10 Mitigation and Adaptive Management for Non-eagle Bird Species.............................95
 

8.10.1 Thresholds .....................................................................................................95
 

8.10.2 Timing of Trigger Evaluation ..........................................................................96
 

8.10.3 Compensatory Mitigation................................................................................97
 

8.11 Responsive Monitoring ............................................................................................100
 

9 REPORTING...................................................................................................................100
 

10 DECOMMISSIONING .....................................................................................................101
 

11 LITERATURE CITED ......................................................................................................102
 

ii	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

LIST OF TABLES
 

Table 1. Chronology of Resource Agency Contact for BP Wind Energy’s Proposed
 

Mohave County Wind Farm Eagle Conservation Plan and Avian Conservation
 

Strategy....................................................................................................................2
 

Table 2. Summary of Golden Eagle Observations within Project area Boundary at
 

Mohave County Wind Farm During 2012 Point Count Surveys1 .............................15
 

Table 3. Summary of Individuals of Sensitive Species Detected by Survey Type Including
 

Size Classification and Status ................................................................................18
 

Table 4. 2011 Golden Eagle Nest Data Collected by WEST for the Mohave County Wind
 

Farm and 10-mile Survey Buffer (Thompson 2011)................................................25
 

Table 5. 2012 Golden Eagle Nest Data for the Mohave County Wind Farm and 10-mile
 

Survey Buffer (Tetra Tech 2012) ............................................................................26
 

Table 6. Variables and Constants Used in the Calculation of Potential Eagle Fatalities for
 

the Mohave County Wind Farm..............................................................................30
 

Table 7a. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind
 

Facilities Nationally in the U.S. ...............................................................................41
 

Table 7b. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind
 

Facilities in Desert Regions of the Western U.S. ....................................................45
 

Table 8. Post-construction Monitoring Frequency ................................................................60
 

Table 9. Comparison of Non-eagle and Eagle Post-Construction Fatality Sampling
 

Design....................................................................................................................62
 

Table 10. Known Causes of Golden Eagle Fatalities in Arizona from AZGFD ........................70
 

Table 11. Golden Eagle Vehicle Collision Data from the Reports, Databases, and Peerreviewed Literature.................................................................................................70
 

Table 12. Golden Eagle Fatalities from Rehabilitation Centers...............................................71
 

Table 13. Summary of Wildlife-vehicle Collision Rates in the U.S. .........................................72
 

Table 14. Statewide Crashes in Arizona (ADOT 2011)...........................................................73
 

Table 15. Summary of Steps Taken to Calculate the Number of Golden Eagles Saved per
 

Mile of Road Where Carcasses are Removed........................................................75
 

Table 16. Eagle Experts Contacted and Their Associated Expertise, Affiliation, and Years
 

of Experience .........................................................................................................80
 

Table 17. Comparison of Inputs and Adaptive Management Between Bottom-up and Topdown approaches...................................................................................................88
 

Table 18. Mitigation Schedule for Non-eagle Birds.................................................................98
 

Table 19. Example Timeline for Reporting and Eagle Take Permitting.................................101
 

iii December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

LIST OF FIGURES
 

Figure 1. Proposed Project Layout, EIS Alternative A With Turbines Removed Due to the
 

Addition of a 1.25-mile No-Build Buffer Around the Squaw Peak Breeding Area
 

and a Curtailment Zone............................................................................................7
 

Figure 2. Eagle Flight Paths and Point Count Locations in 2007/2008 and 2010/2011..........12
 

Figure 3. Eagle Flight Paths and Eagle Point Count Locations in 2012 .................................14
 

Figure 4. 2011 Golden Eagle Breeding Area Locations* and Status......................................21
 

Figure 5. 2012 Golden Eagle Breeding Area Locations* and Status......................................22
 

Figure 6. Palmer Drought Severity Index for Northwest Arizona from January 2000 to April
 

2012*......................................................................................................................32
 

Figure 7. Mean Use by Golden Eagles (Eagle Use/20 min; Pre-construction), Total
 

Golden Eagle Fatalities, and Total Golden Eagle Fatalities/MW (Postconstruction) at 15 Wind Energy Projects in the Western U.S. Compared to
 

Mean Use at Mohave County Wind Farm (Value Circled in Red). ..........................34
 

Figure 8. Slope (in Degrees) of Land within the Mohave County Wind Farm.........................36
 

Figure 9. Aspect of Land Surface within the Mohave County Wind Farm ..............................37
 

Figure 10. Permanent Met Tower Design (Photo from Idaho Falls, Idaho) ..............................53
 

Figure 11. Preliminary Roadways Identified for the Implementation of a Carcass
 

Search/removal Program Using a Kernel Analysis to Define Golden Eagle
 

Habitat and SERI Data on Large Mammal Population Densities (Tribal Lands
 

and the Phoenix Metro Area Were Not Reported or Included in Analyses).............77
 

Figure 12. Adaptive Management of Golden Eagle Fatalities at the Mohave County Wind
 

Farm.......................................................................................................................90
 

Figure 13 Flowchart of Example Non-eagle Bird Mitigation Over First Five Years of Project
 

Operation ...............................................................................................................99
 

LIST OF APPENDICES 

Appendix A Table of All Avian Species Detected 

Appendix B Wildlife Incident Reporting System Protocol 

Appendix C Wildlife Incident Reporting Form 

iv December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

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v December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

ACRONYMS AND ABBREVIATIONS 

AERI American Eagle Research Institute 

APLIC Avian Power Line Interaction Committee 

ARS Arizona Revised Statutes 

AZGFD Arizona Game and Fish Department 

BCS Bird Conservation Strategy 

BGEPA Bald and Golden Eagle Protection Act 

BLM Bureau of Land Management 

Reclamation Bureau of Reclamation 

BP Wind Energy BP Wind Energy North America Inc. 

CI confidence interval 

cm centimeter 

CRP Conservation Reserve Program 

DVC deer-vehicle collision 

ECP Eagle Conservation Plan 

EIS Environmental Impact Statement 

°F degrees Fahrenheit 

GPS Global Positioning System 

IM Instruction Memorandum 

km kilometer 

km2 square kilometer 

MBTA Migratory Bird Treaty Act 

m meter 

met meteorological 

min minutes 

MW megawatt 

NEPA National Environmental Policy Act 

O&M Operations and Maintenance 

PDSI Palmer Drought Severity Index 

Project Mohave County Wind Farm 

Project area area within the Project’s proposed right-of-way boundaries 

ROD Record of Decision 

RSA rotor swept area 

sec second 

SERI Species of Economic and Recreational Importance 

vi December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

USGS U.S. Geological Survey 

USFWS U.S. Fish and Wildlife Service 

UVC ungulate-vehicle collision 

WEST Western EcoSystems Technology, Inc. 

Western Western Area Power Administration 

WIRS Wildlife Incident Reporting System 

vii December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

1 INTRODUCTION 

1.1 Background Information 

BP Wind Energy North America Inc. (BP Wind Energy), a wholly owned, indirect subsidiary of 

BP p.l.c., a publicly traded company, or an affiliate thereof, is proposing to develop, own, and 

operate the Mohave County Wind Farm (Project) in Mohave County, northwestern Arizona, on 

federal lands managed by the Bureau of Land Management (BLM) and the Bureau of 

Reclamation (Reclamation). BP Wind Energy has applied to interconnect the proposed Project 

with either the Western Area Power Administration’s (Western) Liberty-Mead transmission line 

or the Mead-Phoenix transmission line (of which Western is one of several co-owners) for up to 

500 megawatt (MW). The proposed Project would interconnect through a new switchyard to be 

constructed within the Project area. Currently, an Environmental Impact Statement (EIS) is 

being developed for the Project to meet the requirements of the National Environmental Policy 

Act (NEPA) of 1969. The NEPA process was initiated in 2006. BLM is the lead agency for the 

Project and released the Draft EIS for public comment from April 27, 2012 to June 18, 2012. 

The Final EIS is scheduled to be released to the public starting in December 2012. 

BP Wind Energy contracted Tetra Tech to create this Eagle Conservation Plan (ECP) and Bird 

Conservation Strategy (BCS) in order to meet the requirements of BLM Instructional 

Memorandum (IM) 2010-156, which provides direction for compliance under the Migratory Bird 

Treaty Act (MBTA; see Section 1.4.1, Regulatory Framework) and the Bald and Golden Eagle 

Protection Act (BGEPA; see Section 1.4.2, Regulatory Framework). The purpose of this 

document is to provide sufficient information to allow BLM to comply with BLM IM 2010-156. 

The IM states that the U.S. Fish and Wildlife Service (USFWS) must issue a letter of 

concurrence that addresses the adequacy of an Avian Protection Plan (APP) prior to BLM 

signing a Record of Decision (ROD) for BGEPA and NEPA compliance. During the evolution of 

this process, USFWS has changed their preferred terminology from an APP to an ECP and 

BCS, as outlined in the Final Land-based Wind Energy Guidelines (USFWS 2012b). At the time 

when the IM was issued, USFWS had the authority to issues permits (USFWS 2009), but did 

not have implementing guidelines that were subsequently released in the 2011 Draft ECP 

Guidance (USFWS 2011a). The USFWS views the process as described in the IM as one of 

issuing a letter of acknowledgement instead of approval. The USFWS and BLM have agreed 

that consideration of the ECP/BCS as the basis for issuing the letter of acknowledgement will 

satisfy the IM requirement. 

This version of the document will not be the mechanism for permit issuance because BP Wind 

Energy and USFWS will continue to confer on the content of the ECP as BP Wind Energy 

prepares their formal application for a take permit. After submittal of the formal eagle take permit 

application, the USFWS has indicated they will complete their own NEPA analysis to consider 

issuance of a permit using the most current version of the ECP. This ECP/BCS is being 

submitted so that BLM can meet their NEPA requirement in order to issue a ROD for the 

Project. 

This ECP/BCS summarizes the environmental conditions at the Project, avian studies that have 

been conducted and their results, an assessment of potential impacts to eagles and non-eagle 

bird species, avoidance and minimization elements, and compensatory mitigation for 

1 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

unavoidable impacts of the Project. BP Wind Energy has worked closely with USFWS, the 

Arizona Game and Fish Department (AZGFD), BLM, and Reclamation to develop the ECP/BCS 

(Table 1). 

Table 1.	 Chronology of Resource Agency Contact for BP Wind Energy’s Proposed Mohave 

County Wind Farm Eagle Conservation Plan and Avian Conservation Strategy 

Date Purpose Attendees 

January 29, 2008 

Agency meeting at Kingman Field 

Office of BLM that partially focused 

on wildlife surveys. 

BLM (J. Cook, R. Sanchez, D. McClure, J. 

Neckels), BP Wind Energy (L. Mazer, B. 

Gibson) 

June 2008 Agency meeting to discuss survey 

results and proposed future surveys. BLM, AZGFD, and BP Wind Energy 

July 11, 2008 

Written submittal of 2007-2008 

survey results and proposed surveys 

for 2008-2009 year. 

BLM (J. Priest, R. Peck), AZGFD (G. Ritter, 

B. Cary), USFWS (S. Spangel, B. Smith) 

August 13, 2008 Written comments on proposed 

wildlife surveys AZGFD (G. Ritter, L. Canaca, T. Buhr) 

August 25, 2008 

Email survey results from Western 

EcoSystems Technology, Inc. 

(WEST) submitted to BLM. 

WEST (R. Good), BLM (J. Priest, R. Peck, 

J. Cook), BP Wind Energy (B. Gibson, L. 

Mazer) 

May 4, 2009 

Email submittal of 2008-2009 survey 

results and proposed 2009-2010 

survey methods. 

BLM (J. Crockford, J. Neckels, A. Wilhelm, 

J. Stroud) 

July 19, 2011 

Conference call and webinar with 

WEST presenting results of 2011 

eagle nest surveys; and discussion 

of ECP/BCS process with connection 

to NEPA compliance and EIS 

process already underway. Draft 

meeting minutes were circulated for 

input and then finalized later and 

recirculated. 

AZGFD (K. Jacobson, G. Ritter), 

Reclamation (M. Maynard), Western (B. 

Werner), BLM (K. Grove, A. Wilhelm), 

USFWS (B. Wooldridge, C. O’Meilia), 

WEST (J. Thompson), BP Wind Energy (K. 

Wells, T. Eagleston, D. Quick, D. Runyan) 

August 10, 2011 

Conference call to discuss resource 

agencies preliminary impressions of 

baseline wildlife study reports and 

eagle nest survey report; discuss 

resource agency support for EIS 

impact assessment; and discuss 

ECP/BCS process. Draft minutes 

circulated for input with final minutes 

circulated later. BP Wind Energy 

formally commits to preparing an 

ECP/BCS. 

AZGFD (K. Jacobson), Western (B. 

Werner), BOR (M. Maynard), BLM (K. 

Grove, E. Arreola), USFWS (R. Murphy, B. 

Wooldridge, C. O’Meilia), WEST (J. 

Thompson), URS (J. Charpentier), BP 

Wind Energy (K. Wells, D. Quick, T. 

Eagleston) 

September 19, 2011 

In person meeting to discuss 

preliminary impact assessment. Hard 

copy of formal letter from USFWS to 

BP Wind Energy also provided in 

person documenting low impact with 

moderate uncertainty. 

USFWS (R. Murphy), BP Wind Energy (K. 

Wells) 

2	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Table 1.	 Chronology of Resource Agency Contact for BP Wind Energy’s Proposed 

Mohave County Wind Farm Eagle Conservation Plan Avian Conservation 

Strategy (continued) 

Date Purpose Attendees 

October 5-9, 2011 

Informal discussions in person at 

Raptor Research Meeting about 

potential mitigation approaches 

USFWS (R. Murphy, B. Millsap), Tetra 

Tech (L. Nagy, C. Farmer) 

October 13, 2011 

Conference call to discuss existing 

golden eagle fatality data in Arizona 

and get AZGFD feedback on most 

viable eagle mitigation options. 

AZGFD (K. Jacobson, G. Ritter, D. 

Kephart, J. Driscoll), BP Wind Energy (K. 

Wells) 

October 26, 2011 Conference call to discuss proposed 

eagle mitigation concepts. 

AZGFD (K. Jacobson), USFWS (R. 

Murphy, B. Wooldridge, B. Werner), Tetra 

Tech (L. Nagy, C. Farmer), BP Wind 

Energy (K. Wells) 

October 31, 2011 

Telephone call to USFWS Region 2 

Special Agent In Charge for Law 

Enforcement to ask about availability 

of eagle fatality and source data. 

USFWS (N. Chavez), BP Wind Energy (K. 

Wells) 

November 1-17, 2011 

Email and telephone interviews of 

eagle experts regarding potential 

carcass mitigation and risk posed to 

eagles by road-killed carcasses. 

American Eagle Research Institute 

(D. Driscoll), Big Horn Environmental (T. 

Maetchle), Bloom Biological (P. Bloom), G. 

Doney, Montana State University (A. 

Harmata), Tetra Tech (C. Farmer, L. Nagy), 

USFS (T. Grubb), Wildlife Research 

Institute (D. Bittner) 

November 9, 2011 

In-person and webinar meeting from 

Kingman BLM Field Office to provide 

an update on ECP/BCS mitigation 

proposal and gather feedback on 

proposed 2012 Golden Eagle 

surveys. 

BLM (K. Grove, A. Wilhelm), Western (M. 

Schriner), Reclamation (M. Maynard), 

AZGFD (K. Jacobson, D. Kephart), USFWS 

(R. Murphy, B. Werner, B. Wooldridge), and 

BP Wind Energy (K. Wells, B. Gibson, T. 

Eagleston) 

November 15-17, 2011 

In-person discussions during Raptor 

Research Meetings on potential 

mitigation options and risk 

assessment models. 

USFWS (R. Murphy, B. Millsap) and Tetra 

Tech (L. Nagy, C. Farmer) 

November 28, 2011 

Conference call to discuss eagle 

management team suggestion of 

considering out of state eagle 

mitigation. BP Wind Energy formally 

submits proposed eagle mitigation 

conceptual framework via email for 

USFWS eagle management team 

review during telephone call on 

December 1, 2011. 

USFWS (R. Murphy) and BP Wind Energy 

(K. Wells) 

December 7, 2011 

Conference call to discuss USFWS 

eagle management team feedback 

on proposed conceptual mitigation 

framework and seek clarification on 

specifics of adaptive management 

expected 

USFWS (R. Murphy), BP Wind Energy (K. 

Wells), and Tetra Tech (L. Nagy and C. 

Farmer) 

3	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Table 1.	 Chronology of Resource Agency Contact for BP Wind Energy’s Proposed 

Mohave County Wind Farm Eagle Conservation Plan and Avian Conservation 

Strategy (continued) 

Date Purpose Attendees 

December 13, 2011 

Email from BP Wind Energy with the 

Mohave Golden Eagle Survey Plan 

dated 121311 to get feedback on BP 

Wind Energy’s planned golden eagle 

surveys for 2012 

BLM (K. Grove, A. Wilhelm), Western (M. 

Schriner), Reclamation (M. Maynard), 

AZGFD (K. Jacobson, D. Kephart, 

J. Driscoll ), USFWS (R. Murphy, 

B. Werner, B. Wooldridge), and BP Wind 

Energy (K. Wells), Tetra Tech (L. Nagy, C. 

Farmer, and A. Oller) 

December 15, 2011 Conference call to discuss proposed 

2012 Golden Eagle Survey Plan 

AZGFD (K. Jacobson), USFWS 

(B. Werner), BP Wind Energy (K. Wells), 

Tetra Tech (L. Nagy, C. Farmer, and A. 

Oller) 

February 2, 2012 

Provided copy of the Mohave County 

Wind Farm Draft Eagle Conservation 

Plan (Mohave draft ECP 1-31­

12.doc) to agencies for review and 

comments. 

AZGFD (K. Jacobson, G. Ritter, D. Kephart, 

J. Driscoll, J. Kraft, D. Grandmaison), 

USFWS (B. Werner, R. Murphy, B. 

Woodridge), BLM (K. Grove, A. Wilhelm, E. 

Arreola, J. Neckels), Reclamation (M. 

Maynard), Western (M. Schriner, L. 

Hughes), BP Wind Energy (K. Wells, D. 

Runyan), Tetra Tech (L. Nagy), Morgan 

Lewis (D. Quick), and URS (B. Defend) 

February 21, 2012 

Conference call to gather comments 

on Mohave Wind Farm Project Eagle 

Conservation Plan. 

AZGFD (K. Jacobson, G. Ritter, D. 

Kephart, J. Driscoll, J. Kraft, D. 

Grandmaison), USFWS (B. Werner, R. 

Murphy), BLM (K. Grove), BP Wind Energy 

(K. Wells, D. Runyan, T. Eagleston, M. 

Rigo, K. Pitney), Tetra Tech (L. Nagy, 

C. Farmer, and A. Oller), Morgan Lewis (D. 

Quick) 

April 17, 2012 Conference call to discuss carcass 

search/removal mitigation location. 

AZGFD (J. Kraft, D. Grandmaison, D. 

Kephart, J. Driscoll, M. Ingradli) USFWS 

(B. Werner), BLM (K. Grove, E. Arreola), 

BP Wind Energy (D. Runyon, D. Gonzales, 

K. Wells), Tetra Tech (L. Nagy, A. Oller, C. 

Farmer), URS (J. Charpentier) 

April 26, 2012 

Conference call with USFWS to 

discuss AZGFD eagle mitigation 

protocol. 

USFWS (R. Murphy, B. Warner), BP Wind 

Energy (K. Wells), Tetra Tech (L. Nagy, C. 

Farmer) 

May 9, 2012 Conference call to discuss AZGFD 

Carcass Removal Plan protocol. 

AZGFD (T. Jacobson, G. Ritter, D. 

Grandmaison), USFWS (B. Werner), BP 

Wind Energy (K. Wells), Tetra Tech (L. 

Nagy, C. Farmer, J. Garvin), URS, (J. 

Charpentier) 

June 7, 2012 Conference call to discuss AZGFD 

Carcass Removal Plan protocol. 

USFWS (B. Werner), BP Wind Energy (K. 

Wells, D. Gonzalez), Tetra Tech (L. Nagy, 

C. Farmer, J. Garvin, A. Oller), BLM (K. 

Grove, E. Arreola), Reclamation (M. 

Maynard), NPS (J. Holland, M. Boyles, A. 

Howard), Morgan Lewis (D. Quick), AZGFD 

(D. Kephart, G. Ritter, T. Jacobson, R. 

Schweinsburg, M. Piorkowski) 

4	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Table 1.	 Chronology of Resource Agency Contact for BP Wind Energy’s Proposed 

Mohave County Wind Farm Eagle Conservation Plan and Avian Conservation 

Strategy (continued) 

Date Purpose Attendees 

June 26, 2012 

Conference call to discuss which 

variant of the carcass 

search/removal plan was closest to 

meeting USFWS regulatory needs. 

USFWS (R. Murphy), BP Wind Energy (K. 

Wells), Tetra Tech (L. Nagy, C. Farmer) 

July 5, 2012 

Provided copy of the 2nd draft of the 

Mohave County Wind Farm Draft 

Eagle Conservation Plan (BP 

Mohave ECP-ACS 07052012.docx) 

to agencies for review and 

comments. 

AZGFD (K. Jacobson, G. Ritter, D. 

Kephart, J. Kraft, D. Grandmaison), 

USFWS (B. Werner, R. Murphy, B. 

Woodridge, C. Omelia), BLM (K. Grove, A. 

Wihelm, E. Arreola, J. Neckels), 

Reclamation (M. Maynard, F. Streier), NPS 

(J. Holland, M. Boyles), Western (L. 

Hughes), BP Wind Energy (K. Wells, D. 

Runyan, M. Rigo), Tetra Tech (L. Nagy, C. 

Farmer), Morgan Lewis (D. Quick), and 

URS (B. Defend, L. Watson, J. 

Charpentier) 

August 1, 2012 

Conference call to gather comments 

on the 2nd draft of the Mohave 

County Wind Farm Eagle 

Conservation Plan. 

AZGFD (K. Jacobson, D. Kephart, J. Kraft, 

D. Grandmaison M. Piorkowksi), USFWS 

(B. Werner, R. Murphy), BLM (K. Grove, A. 

Wihelm), BP Wind Energy (K. Wells), Tetra 

Tech (L. Nagy, A. Oller, C. Farmer, J. 

Garvin) 

August 22, 2012 Conference call to discuss the 

carcass mitigation plan. 

USFWS (R. Murphy), AZGFD (K. 

Jacobson), BP Wind Energy (K. Wells), 

Tetra Tech (L. Nagy, C. Farmer) 

September 13, 2012 Conference call to discuss the 

carcass mitigation plan. 

USFWS (R. Murphy), AZGFD (K. 

Jacobson), BP Wind Energy (K. Wells), 

Tetra Tech (L. Nagy, A. Oller, C. Farmer, J. 

Garvin) 

October 2, 2012 

In-person meeting to discuss 

Alternatives and golden eaglespecific avoidance and minimization 

measures needed for USFWS 

acknowledgement letter. 

USFWS (R. Murphy, J. Thompson, B. 

Werner), BLM (J. Neckels, K. Grove, A. 

Wilhelm, E. Arreola, E. Masters), 

Reclamation (M. Maynard), NPS (J. 

Holland), AZGFD (J. Driscoll), Western (G. 

Daino), BP Wind Energy (D. Runyan, K. 

Wells, J. Madison), Tetra Tech (L. Nagy), 

URS (J. Charpentier, B. Defend) 

October 15, 2012 

Telephone conversation to clarify 

details associated with 1.25-mile nobuild buffer and curtailment zone. 

USFWS (R. Murphy), BP Wind (K. Wells), 

and Tetra Tech (L. Nagy) 

1.2 Project Description 

The Project area includes approximately 38,099 acres of public land managed by the BLM 

Kingman Field Office, and approximately 8,966 acres of land managed by Reclamation, for a 

total of 47,066 acres. The Project area is located approximately 64 kilometers (km) (40 miles) 

northwest of Kingman, Arizona in the White Hills of Mohave County. Project features as 

described in the EIS include wind turbines; foundations and pad-mounted transformers; 

electrical, communication, and distribution systems; interior access roads; substations; a 

switchyard; and ancillary facilities including an Operations and Maintenance (O&M) building, 

5	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

temporary laydown/staging areas, mobile batch plants, and temporary and permanent 

meteorological (met) towers. The exact location of the wind turbines, roads, and transmission 

and distribution lines will be determined during final design following completion of windresource data analyses and other environmental studies including identification of construction 

constraints and sensitive cultural or natural resources to be avoided (Figure 1). 

The Project would generate and deliver electrical power to the regional electrical transmission 

grid by interconnecting with an existing transmission line passing through the Project Area. The 

potential interconnection points include the Liberty-Mead 345-kV or Mead-Phoenix 500-kV 

transmission lines, both of which cross the southern portion of the Project area and are 

operated by Western. BP Wind Energy has applied to generate up to a maximum nameplate 

capacity of 500 MW at the Project and has filed interconnection requests with Western that 

commit the firm to certain generating capacities (dependent on the specific transmission line) if 

the Project is approved. Any alterations to the Project that lower the generation capacity below 

these respective levels would cause the Project to fail to meet its stated purpose and need 

(BLM 2012). 

Up to 283 turbines are proposed to be installed within the corridors in the Project area; each 

would have the capacity to generate between 1.5 to 3.0 MW. Depending on the turbine model 

used, the turbine hubs would be between 80 meters (m) (262 feet) and 105 m (345 feet) above 

the ground, and the turbine blades would extend between 39 m (126 feet) and 59 m (194 feet) 

above the hub. At the top of their arc, the blades would be between 119 m (390 feet) and 164 m 

(539 feet) above the ground. The energy generating capacity of the Project would depend on 

the turbine model selected, the transmission line used, and the turbine corridors approved by 

BLM and Reclamation. The Project would have a nameplate generating capacity of 425 MW in 

the event the Project interconnects to the Liberty-Mead line, and 500 MW in the event the 

Project interconnects to the Mead-Phoenix line. The desired generation level could be achieved 

by different numbers of turbines, depending on the turbine model(s) selected by BP Wind 

Energy, and the land area approved by BLM and/or Reclamation in accordance with the 

decisions made by these agencies in their respective RODs. 

BP Wind Energy has used a “turbine corridor” approach instead of focusing on specific turbine 

locations in order to account for the degree of flexibility required for a project of this scale and 

complexity and given the long federal permitting timeline anticipated at the time of the initial 

development application submitted to BLM in August of 2006. By providing Project-specific data 

within broad turbine corridors, BP Wind Energy preserves flexibility to micro-site all elements of 

the Project in order to avoid and minimize impacts identified through NEPA and other analyses. 

In addition, BP Wind Energy preserves critical business flexibility to select turbine models and 

layout based on the options commercially available at the time a Notice to Proceed is issued. As 

a result of the turbine corridor approach, the EIS describes and analyzes impacts based on 

three turbine-parameter specification ranges (see above). 

6 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Figure 1.	 Proposed Project Layout, EIS Alternative A With Turbines Removed Due to the 

Addition of a 1.25-mile No-Build Buffer Around the Squaw Peak Breeding Area 

and a Curtailment Zone. 

7	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

The Project boundary analyzed for baseline conditions has shifted to accommodate comments 

received and the results of scoping. BP Wind Energy previously proposed a Project footprint 

east and southeast (Map 2-11 of the Draft EIS, BLM 2012) of what is currently proposed 

(Alternative A in the Draft EIS, BLM 2012). The previously proposed footprint was comprised of 

a checkerboard mix of private and public lands administered by BLM and Reclamation. The 

footprint was shifted for four primary reasons including: 1) constructability; 2) land access; 

3) environmental constraints; and 4) agency and public feedback from scoping. The previous 

footprint was composed of a higher proportion of lands with rugged topography including ridges, 

mountain peaks, and mines. These characteristics imposed engineering and environmental 

impact constraints as well as increased costs. In addition, comments received during the 

scoping period in the initial stages of the EIS suggested that a footprint shift would result in a 

project with fewer impacts to the human and natural environment. In response, BP Wind Energy 

proposed the current footprint to provide a better sited project with fewer constraints that could 

affect sensitive resources in the area. In the ECP/BCS, this earlier footprint will be referred to as 

the prior footprint. The proposed layout represents a shift of turbine corridors to the west. 

The currently proposed Project (Alternative A) that was developed in 2011 prior to the 

completion of golden eagle surveys, consists of a maximum of 283 turbines, and a Project area 

of approximately 47,066 acres. Two additional development alternatives are considered in the 

Draft EIS (BLM 2012). Alternative B was developed to address concerns raised by the Lake 

Mead National Recreation Area which is a unit of the National Park Service (NPS), as well as by 

private landowners, regarding visual and noise impacts from turbines located in proximity to 

NPS and surrounding lands. Turbine corridors in Alternative B are eliminated or shortened on 

lands managed by the BLM and Reclamation, and this increases the distance from turbines to 

private lands. Alternative C was developed to address similar concerns, but differs from 

Alternative B in that more turbines are moved from areas near private lands to lands managed 

by the BLM. Both Alternatives B and C reduce the maximum number of turbines to 208 by 

removing turbines from the northwestern (Alternative B) edge or southern edge (Alternative C) 

of the Project area but differ in the location of the turbine strings. Alternative B would have a 

Project area of approximately 34,720 acres, whereas Alternative C would have a Project area of 

approximately 35,302 acres. Either development alternative would result in potential avoidance 

and minimization of impacts to eagles and other birds due to the reduction in turbine numbers. 

To be conservative, impacts of the Project are discussed based on Alternative A unless 

explicitly stated otherwise. 

Regardless of which alternative is chosen, BP Wind Energy is implementing two types of 

avoidance and minimization measures relative to potential eagle impacts, both associated with 

the Squaw Peak golden eagle breeding area (see Section 2.3 for details). First, BP Wind 

Energy is voluntarily implementing a no-build buffer within 2 km (1.25 miles) of the known active 

and alternate golden eagle nests of the Squaw Peak breeding area as documented by baseline 

surveys. Second, BP Wind Energy is removing potential turbines from two township-range 

sections approximately 3 km (1.9 miles) south of the Squaw Peak breeding area (Sections 20 

and 21 in T29N, R20W). 

The Project term is 30 years; however, incidental take permits are limited to 5 years at this time 

(USFWS 2011a). Therefore, both potential Project design elements that would be in effect for 

the Project lifetime are discussed, along with additional avoidance, minimization, and 

8 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

compensatory mitigation measures that are proposed for a 5-year timeline to correspond to the 

current duration of eagle take permits. 

1.3 Environmental Setting 

The Project area is located in the White Hills, situated between the Detrital Valley Basin and 

Black Mountains to the west and the Hualapai Valley Basin and Grand Wash Cliffs to the east 

(U.S. Geological Survey [USGS] 1999, WRCC 2012). The Colorado River and Lake Mead are 

to the north and the Cerbat Mountains are south of the Project area. The Project area is located 

in the Mojave Desert ecoregion, a transitional zone between the warmer Sonoran Desert to the 

south and the higher and cooler Great Basin Desert to the north (Lowe 1985, USEPA 2007). 

The dominant vegetation type within the Project is Sonora-Mojave Creosotebush-White Bursage 

Desert Scrub which is described as 2-50 percent cover of small-leaved, broad-leaved, and 

drought-adapted shrubs (NatureServe 2011). This vegetation type is dominated by 

creosotebush (Larrea tridentata) and white bursage (Ambrosia dumosa). Within the Project area 

and its surroundings, this vegetation type exhibits a great deal of variation in its secondary 

species, which change with elevation, soil texture, and available precipitation. Other vegetation 

in the Project area includes white burrobush (Hymenoclea salsola), brittlebush (Encelia 

farinosa), Mojave yucca (Yucca schidigera), and Joshua trees (Yucca brevifolia; Thompson et 

al. 2011a). Numerous species of cactus also occur. 

Mohave County experiences milder summers and colder winter temperatures than the low 

desert regions of Arizona. Average annual temperatures near the Project area are in the low 

60s degrees Fahrenheit (°F); 15-20 degrees Celsius (°C). Summer temperatures generally 

range from the mid-70s to the mid-90s °F (24 to 35 °C). In winter, early morning temperatures 

normally drop to the low 30s and reach the mid-50s °F (-1 to 10 °C) by the afternoon (WRCC 

2012). Precipitation is limited in the Project area and its surroundings, and ranges from about 8 

to 10 inches (20 to 25 centimeters [cm]) per year (WRCC 2012). The terrain is variable 

throughout the Project area and ranges from 585 m (1,920 feet) to 1,169 m (3,836 feet) above 

sea level (USGS 1999). The greatest topographic relief is in the northwestern portion of the 

Project area on land managed by Reclamation. The primary land uses within the Project area 

are utility and road rights-of-way, Off Road Vehicle (ORV) use and other recreational activities, 

and livestock grazing. 

1.4 Regulatory Framework 

Native migratory birds are protected under a variety of federal and state laws and regulations. 

Relative to the Project, these include the MBTA, BGEPA, BLM Instructional Memorandum 2010­

156, and Arizona Revised Statute 17. In areas of federal land, the NEPA permitting process is 

required, and Memoranda of Understanding between BLM and AZGFD have been developed to 

clarify management responsibilities. These regulations are described in the following 

subsections. 

1.4.1 Migratory Bird Treaty Act 

Under the MBTA it is unlawful to pursue, hunt, take, capture or kill; attempt to take, capture, or 

kill; possess, offer to or sell, barter, purchase, deliver or cause to be shipped, exported, 

imported, transported, carried or received any native migratory bird, part, nest, egg or product. 

The USFWS has established a permitting scheme for a variety of intentional activities, such as 

9 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

hunting and scientific research, but has not done so for the incidental take of migratory birds 

associated with otherwise lawful activities. As a result, there is no permitting framework that 

allows a company to protect itself from liability resulting from take at wind facilities. BP Wind 

Energy has been coordinating with USFWS to develop this ECP/BCS to represent best 

management practices and good-faith efforts to minimize impacts to migratory birds and comply 

with the MBTA. 

1.4.2 Bald and Golden Eagle Protection Act 

The BGEPA prohibits the take of any bald or golden eagle, alive or dead including any part, 

nest, or egg. “Take” is defined as “pursue, shoot, shoot at, poison, wound, kill, capture, trap, 

collect, molest or disturb” a bald or golden eagle. “Disturb” means to agitate or bother an eagle 

to a degree that causes, or is likely to cause (1) injury to an eagle; (2) a decrease in its 

productivity, by substantially interfering with normal breeding, feeding, or sheltering behavior; or 

(3) nest abandonment, by substantially interfering with normal breeding, feeding, or sheltering 

behavior. Historically permits were not available under the BGEPA; however, a rule change in 

50 Code of Federal Regulations in November 2009 provided a mechanism to acquire permits 

for incidental take associated with otherwise lawful activity (§22.26). The Draft ECP Guidance 

outlining the steps requested for permits was released in January 2011 and was utilized in the 

development of this ECP/BCS. A revised Technical Appendix to the Draft ECP Guidance was 

released in August 2012 that replaces the prior appendix and provides an update on current 

methods being used to assess and document risk to eagles related to wind development 

(USFWS 2012a). Although the current permit period is limited to five years, this ECP/BCS has 

been developed for the entire 30-year life of the Project. 

1.4.3 BLM Instruction Memorandum No. 2010-156 

In July 2010, the BLM issued IM No. 2010-156 to all field officials (BLM 2010a). The purpose of 

the memorandum was to provide direction for compliance with BGEPA in the interim period 

between the final rule allowing for incidental take permits (USFWS 2009), and the establishment 

of criteria for how to issue programmatic take permits for golden eagles. The memorandum 

directed BLM officials to incorporate consideration of golden eagles and their habitat in the 

NEPA analysis for all renewable energy projects. Furthermore, the IM states that BLM will not 

issue a notice to proceed for any project with the potential to impact eagles until the USFWS 

provides a letter of acknowledgement regarding the applicant’s draft APP (see Section 1.1 for 

more details). 

1.4.4 National Environmental Policy Act 

NEPA is an act of Congress established to ensure that the environmental impacts of any federal 

action are fully considered and that appropriate steps are taken to mitigate potential 

environmental impacts. An EIS is being prepared for the Project in compliance with NEPA in 

order to analyze and disclose the potential impacts of the Project. The BLM is the lead agency 

responsible for preparing the EIS. Other agencies (federal, state, and local) cooperating with 

BLM in the preparation of the EIS include Reclamation, Western, NPS, AZGFD, and Mohave 

County. The Hualapai Tribe, a governmental entity, is also cooperating with BLM in the 

preparation of the EIS. 

10 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

1.4.5 Memoranda of Understanding between BLM and AZGFD 

In November 2007, the BLM and AZGFD entered into a memorandum of understanding 

(Agreement Number AZ-930-0703) to work cooperatively to manage resources on public lands 

within Arizona. This memorandum recognized AZGFD as the agency responsible for managing 

fish and wildlife populations on BLM public lands within Arizona, and BLM as the agency 

responsible for managing fish and wildlife habitat on these lands. BLM agreed in the 

memorandum to manage uses and users of BLM public lands so that habitat on these lands will 

support and enhance fish and wildlife populations consistent with AZGFD’s trust responsibilities, 

goals, and objectives. Both parties to the memorandum agreed to cooperate and participate in 

the development of all plans or programs that affect fish and wildlife management on BLM 

public lands in Arizona. 

In December 2010, the BLM and AZGFD entered into a memorandum of understanding 

(Agreement Number AZ-2010-5) with respect to their roles on the Project. Specifically, the BLM 

is designated as the lead agency with responsibility for the completion of the EIS and the ROD. 

AZGFD is identified as a cooperating agency whose role is to provide technical assistance with 

respect to wildlife, hunting, recreation, and environmental issues where AZGFD has special 

expertise or jurisdiction by law. 

1.4.6 Arizona State Statutes 

Under the Arizona Revised Statutes (ARS) Title 17 §17-102 wildlife is the property of the state 

and under both ARS §17-309 (criminal penalties) and §17-314 (civil liability) it is unlawful to take 

wildlife except as permitted by the Arizona Game and Fish Commission. Take, as applicable in 

the context of wind development, is defined as pursuing or killing wildlife where wildlife includes all 

birds, bird nests, and young (ARS §17-101). ARS §17-235 authorizes the Arizona Game and Fish 

Commission to regulate the taking of migratory birds, in compliance to the MBTA, specifically with 

respect to seasons, bag limits, possession limits, and other regulation. ARS §17-236 states, “It is 

unlawful to take or injure any bird or harass any bird upon its nest, or remove the nests or eggs of 

any bird, except as may occur in normal horticultural and agricultural practices and except as 

authorized by commission order.” 

2 MONITORING AND SURVEYING TO DATE 

2.1 Bird Use Survey Methods 

Point count surveys were conducted to evaluate the species, timing, and distribution of birds 

within the Project area. Point counts were conducted by WEST for all bird species from 2007 – 

2011 (Thompson et al. 2011a; Appendix A) and by Tetra Tech for golden eagles in 2012. 

During the 2007-2008 season, surveys were conducted at seven 800-m radius fixed-point bird 

use locations based on the prior footprint on BLM land (Figure 2). When the Project area 

changed to the proposed footprint, five new fixed-point bird use sites were surveyed in the 

2010-2011 season on Reclamation land (Figure 2). The twelve points were representative of the 

habitats and topography within the Project area. Every bird observed during each 20-minute 

(min) fixed-point bird use survey was recorded, but observations of large birds beyond the 800­

m radius, and small birds beyond a 100-m radius were excluded from the statistical analyses. 

11 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 2. Eagle Flight Paths and Point Count Locations in 2007/2008 and 2010/2011 

12 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Large birds included waterbirds, waterfowl, rails and coots, gulls and terns, shorebirds, raptors 

(defined here as kites, accipiters, buteos, harriers, eagles, falcons, vultures, ospreys, and owls), 

upland game birds, doves/pigeons, large corvids (e.g., ravens, magpies, and crows), goatsuckers, and kingfishers whereas small birds included passerines (excluding large corvids), 

swifts/hummingbirds, and woodpeckers (Appendix A). 

Species or best possible taxonomic identification (e.g., genus), number of individuals, sex and 

age class (if possible), distance from plot center when first observed, closest distance, flight 

altitude above ground, activity (behavior), and habitat(s) used by birds were recorded for each 

observation. The behavior of each bird observed, and the vegetation type in which or over which 

the bird occurred, were recorded based on the point of first observation. Approximate flight 

height and distance from plot center at first observation were estimated to the nearest 5-m (16­

ft) interval. Classification of species as resident or migrant was determined using the annual 

pattern of occurrence in Mohave County according to Peterson Guides Bird Finder (2011) and 

may differ from the classification used in Thompson et al. 2011a; species for which the majority 

of presence was documented during spring and fall migration periods were considered 

migrants, all other species were considered residents. 

Fixed-point bird use surveys were conducted from April 21, 2007, through November 11, 2008, 

and from September 3, 2010, through May 30, 2011. Surveys were conducted approximately 

once per week during the spring (March 11 to May 31) and fall (August 1 to November 15) 

seasons and twice monthly during the winter season (November 16 to March 10). Summer 

surveys were not conducted because the area was expected to support birds primarily during 

migration and wintering periods. Surveys were carried out during daylight hours and survey 

periods were varied to approximately cover all daylight hours during a season. To the extent 

practical, each point was surveyed about the same number of times. 

In 2012, golden eagle point count surveys were conducted at 16 fixed and five rover count 

locations within and near the Project area (Figure 3). Rover locations allowed surveyors to be 

responsive to areas of perceived or observed eagle use. All count locations were chosen to 

maximize visual coverage of the Project area, to provide views of areas where eagle use was 

expected based on topography and previous observations, and to provide a representative 

sample of use throughout the Project area. Nine rounds of golden eagle point count surveys 

were conducted every other week from January 14 to May 9, 2012. Each round of surveys 

consisted of a 2-hour point count at each of the 16 point count and at two of the rover locations. 

Survey start times were rotated so that all periods of daylight were sampled at all locations. 

The data recorded for each golden eagle point count included numbers and age classes of 

golden eagles seen, flight height, minutes of golden eagle flight over the Project area that were 

within the approximate rotor swept area (RSA) height range of the anticipated turbine model at 

the time surveys were designed (35 – 125 m above ground), notes on flight and other 

behaviors. Each golden eagle flight observation was drawn on a topographic map or aerial 

image of the Project area and digitized into a geographic information system (GIS). There was 

no distance cut-off for observations. Eagles observed within or near the Project area but outside 

of the survey period (e.g., when surveyors were traveling between point count locations) were 

recorded as incidental observations and in the same manner as for eagle observations made 

during surveys. Flight paths of incidental eagle sightings were used to help delineate areas of 

eagle use within and near the Project area. 

13 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 3. Eagle Flight Paths and Eagle Point Count Locations in 2012
 

14 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

2.1.1 Golden Eagle Results 

No golden eagles were seen during the 2007-2008 surveys, resulting in a golden eagle mean use of 

0.00 eagles/20-min for the 2007-2008 survey year. In the 2010-2011 survey year, four golden 

eagles were seen in three groups within the Project area. Two golden eagles of unknown age were 

seen in winter on February 7, 2011. In spring, one adult golden eagle was seen on March 24, 2011, 

and one adult golden eagle was seen on April 27, 2011. No golden eagles were observed in the fall. 

All four golden eagles flew within the RSA along the northwestern portion of the Project area on 

Reclamation land (Figure 2). Across all 2011 surveys, golden eagle mean use was 0.02, 0.00, and 

0.03 eagles/20-min in the spring (March 11 – May 31), fall (August 1 – November 15), and winter 

(November 16 – March 10) seasons, respectively. 

Four golden eagles were seen incidentally between April 2007 and May 2011, one observed during 

bird use surveys but outside of the survey plot, and three during other wildlife surveys (Figure 2). 

Incidental sightings are those made outside of formal sampling plots or times; although they are 

used to detect presence of birds, incidental sightings are not included in the statistical analysis of the 

sample data. 

In 2012, a total of 30 observations of eagles were made during 320 hours of observation, of which 

nine occurred within the Project area (Table 2, Figure 3) for a mean use of 0.03 eagles per hour. 

Eight of the nine eagle observations within the Project area were individuals in flight. These 

observations recorded 5.17 minutes of flight within the RSA while within the Project area (Table 2). 

Eagle observations were recorded from point count locations 1 and 6, and rover locations R2 and 

R4. Most flights occurred close to active nests, with little movement into the interior of the Project 

area (Figure 3). 

Table 2.	 Summary of Golden Eagle Observations within Project area Boundary at Mohave 

County Wind Farm During 2012 Point Count Surveys1 

Date Point Survey or 

Incidental 

Time 

Eagle 

First 

Observed 

Time 

Eagle 

Last 

Observed 

Age2 Activity3 

Approximate 

Flight 

Height4

(m) 

Eagle 

Minutes at 

RSA Height 

in Project 

area

Low High 5

1/31/2012 6 Survey 1611 1659 A FL 180 1200 0 

1/31/2012 6 Survey 1611 1613 U FL 180 250 0 

1/30/2012 16 Incidental 1339 1346 A FL 10 125 N/A 

1/30/2012 16 Incidental 1339 1346 A FL 10 150 N/A 

1/30/2012 R2 Survey 1458 1625 A FL/PE 0 350 2 min 35 sec 

1/30/2012 R2 Survey 1458 1645 A FL/PE 0 350 2 min 35 sec 

2/12/2012 7 Incidental 1627 1627 U FL/PE 0 300 N/A 

3/1/2012 R2 Survey 1005 1026 A FL 300 800 0 

3/1/2012 R2 Survey 1010 1023 A FL 500 800 0 

3/13/2012 6 Survey 1102 1115 A FL 250 1000 0 

4/23/2012 1 Incidental 1845 1941 I PE/FL 0 5 N/A 

4/23/2012 1 Incidental 1859 1941 A FL/PE 0 20 N/A 

4/24/2012 1 Survey 809 809 U FL/PE 0 2 0 

5/9/2012 1 Survey 1229 1425 A PE 0 0 0 

1. Only those flight paths observed within the Project area are included in this table. 

2. A = adult, I = immature, U = unknown 

3. FL = flight, PE = perched 

4. Flight height = height above ground 

5. N/A = Not applicable, eagle minutes not reported for incidental sightings because they occur outside of standardized surveys 

15	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

2.1.2 Non-eagle Bird Species Results 

During 323 point-count surveys conducted by WEST (Thompson et al. 2011a), a total of 683 

individual birds consisting of 35 species were observed in 518 separate groups (defined as one 

or more individuals; Appendix A). Regardless of bird size, four species (11.4 percent of all 

species) composed 51.5 percent of all observations: black-throated sparrow, common raven, 

horned lark, and turkey vulture. All four species are potentially resident breeders within the 

Project area and do not have special status (Appendix A). All other species comprised less than 

5 percent of the observations, individually. All fixed-point surveys combined had a mean species 

richness of 0.31 large bird species/800-m plot/20-min survey and 0.55 small bird species/100-m 

plot/20-min survey. Overall mean use by all birds was 1.70 birds/plot/20-min survey; however, 

large birds were surveyed on different-sized plots than small birds. The highest overall large bird 

use occurred during the spring (0.97 birds/800-m plot/20-min survey), followed by winter (0.50) 

and fall (0.31). Small bird use was highest in the spring (2.33 birds/100-m plot/20-min survey), 

followed by the winter (0.55) and fall (0.45). For all large bird species combined, use was 

highest at locations in the east-central section of the Project area (2006-2007) where the 

topography is gently rolling and dispersed Joshua tree woodland habitat is prevalent. Small bird 

use was also high in this type of habitat (2006-2007), as well along the western slope of Squaw 

Peak (2010-2011). 

Annual large-bird mean use was 0.56 birds/800-m plot/20-min survey, with raptors making up 

40.3 percent of large birds detected at the Project area (Appendix A). Overall-mean raptor use 

at the Project area was 0.23 raptors/800-m plot/20-min survey, with the highest use recorded 

during the spring (0.46 raptors/800-m plot/20-min survey) and lowest during the winter (0.08). 

Raptors composed 47.6 percent of the overall bird use in the spring, 41.7 percent in the fall, and 

15.9 percent in the winter. The most common raptor species observed were turkey vulture, redtailed hawk, and American kestrel, with turkey vulture and red-tailed hawk having the highest 

exposure index among raptors (0.09 and 0.03 raptors flying within the RSA height/800-m survey 

plot/20-min survey, respectively) and the second and third highest among all bird species, 

respectively. Turkey vultures made up nearly half of all detections of raptor species (36 out of 73 

individuals). Mean raptor use in the Project area ranked seventh lowest compared to 43 other 

wind energy facilities from across North America that implemented similar protocols to this study 

and had data for three or four different seasons. However, the mean raptor use in the Project 

area was highest among the three studies available from Arizona (range from 0.13 to 0.23 

raptors/800-m plot/20-min survey; Thompson et al. 2011a). 

Annual small-bird mean use was 1.07 birds/200-m plot/20-min survey, with passerine species 

making up 98.0 percent of small birds detected at the Project area (Appendix A). Black-throated 

sparrow had the highest use by any one species during all three seasons. Northern roughwinged swallow was the only small bird species recorded flying within the RSA based on initial 

flight height observations and had an exposure index of less than 0.01 birds flying within RSA 

height/100-m plot/20-min survey. Passerines were observed during 76.5 percent of spring 

surveys, 23.5 percent of fall surveys and 18.8 percent of winter surveys. Although 76.5 percent 

of passerine observations occurred during the spring, they were primarily of species considered 

to be potential residents within the Project area (Appendix A), suggesting that the site was used 

primarily by resident birds and not as a stopover for large numbers of migrants. 

16 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

2.1.3 Sensitive Species 

Sensitive species are defined here as those federal or state listed as threatened, endangered, 

or candidate for listing; USFWS Birds of Conservation Concern (BCC; USFWS 2008), BLM 

Sensitive species (BLM 2010b); Species of Greatest Conservation Need (SGCN) under the 

Arizona State Wildlife Action Plan (AZGFD 2010); or Species of Continental Importance (SCI) 

under the North American Landbird Conservation Plan developed by Partners in Flight (Rich et 

al. 2004). No listed or candidate bird species were detected during avian surveys. Five bird 

species were detected that are considered BCC in the Bird Conservation Region (BCR) 

containing the Project area, BCR 33 (Sonoran and Mojave Deserts): Bendire’s thrasher, 

burrowing owl, Costa’s hummingbird, gilded flicker, and prairie falcon (Table 3). Both the 

burrowing owl and gilded flicker are also listed as Sensitive by the BLM, in addition to golden 

eagle (see Section 2.1.1 for additional details; Table 3). Additionally, 20 species were detected 

that are considered SGCN including BCC and BLM Sensitive species (Table 3). There were 15 

species detected that are considered SCI including several species ranked as BCC and SGCN 

(Table 3). 

2.2 Songbird Migration Surveys 

Songbird migration surveys were conducted for passerines between March 1 and May 30, 2009 

to encompass the bulk of the spring migration season, as well as some of the early nesting 

season for songbirds in this region. These surveys were performed in response to a request 

from AZGFD to measure use of the Project by night-migrating passerines that may use the 

Project area as stopover habitat during the day. Because avian point count surveys (Section 

2.1) focused on proposed turbine locations on ridges and did not target bird use in washes or at 

stock tanks, the songbird migration surveys utilized a paired-point approach to assess whether 

or not species using the site appeared to select for wash habitats over ridge/upland habitats. 

This survey effort was based on the assumption that if migrant birds were using the Project area 

as a stopover site during migration, wash habitats would show elevated use by migrants 

because these areas typically contain more habitat complexity/diversity than other areas. 

Songbird migration surveys were conducted for 10 minutes at 21, 100-m-radius circular plots 

around fixed observation points following standard methods (Reynolds et al. 1980). Ten point 

count locations were established within turbine corridors proposed at the time of surveys, which 

were typically located on ridges. Each turbine plot was paired with a plot located within an 

adjacent wash, with plots in washes located a minimum of 400 m from turbine plots. One 

additional plot was surveyed at the Senator Mountain Stock Tank. Two sets of paired points, 

along with the single station at the Senator Mountain Stock Tank, were located outside of the 

current (as of July 2011) Project area; however, data from these points were included in the 

analysis and included in this report, as the primary goal of these surveys was to assess the area 

(not necessarily just the current Project area) for its potential as a stopover site for migrant 

songbirds during the spring migration. All birds observed during each survey were recorded. All 

passerines were recorded, regardless of the distance from the observer, but only those detected 

within 100 m from the observer were used for analysis. Surveys were conducted every other 

week during the survey period from sunrise to approximately 10:00 am, and the survey order 

rotated so that each point was sampled at various times in the morning. 

17 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 3. Summary of Individuals of Sensitive Species Detected by Survey Type Including Size Classification and Status 

Species Common 

Name 

Species Scientific 

Name 

Size 

Class 

Resident 

Classification 

Total Number Detected 

USFWS 

Status1 

BLM 

Status2 

State 

Status3 

Species of 

Continental 

Importance4

Point 

Counts 

Songbird 

Migration Incidental 

Abert's Towhee Pipilo aberti Small Resident - - 1 - - 1B WL3 

Bendire's thrasher Toxostoma bendirei Small Resident - - 4 BCC - 1C WL3 

black-tailed gnatcatcher Polioptila melanura Small Resident 1 12 11 - - 1C AS1 

black-throated sparrow Amphispiza bilineata Small Resident 181 428 108 - - - AS1 

Brewer's sparrow Spizella breweri Small Migrant 2 90 120 - - 1C WL2 

Bullock's oriole Icterus bullockii Small Resident - - 1 - - 1C -

burrowing owl Athene cunicularia Small Resident - - 1 BCC S 1B -

cactus wren 

Campylorhynchus 

brunneicapillus Small Resident 26 213 47 - - - AS1 

common poorwill Phalaenoptilus nuttallii Large Resident - - 4 - - 1C -

Costa's hummingbird Calypte costae Small Resident - 4 3 BCC - 1C WL3 

Gambel's quail Callipepla gambelii Large Resident 28 56 47 - - - AS1 

gilded flicker Colaptes chrysoides Small Resident 1 - 4 BCC S 1B -

golden eagle Aquila chrysaetos Large Resident 5 - 3 - S 1A -

lark bunting 

Calamospiza 

melanocorys Small Migrant - 1 - - - - AS1 

loggerhead shrike Lanius ludovicianus Small Resident 20 84 45 - - 1C -

phainopepla Phainopepla nitens Small Resident - - 4 - - 1C AS1 

prairie falcon Falco mexicanus Large Resident - - 1 BCC - 1C -

sage sparrow Amphispiza belli Small Resident 2 2 - - - 1C AS1 

sage thrasher Oreoscoptes montanus Small Migrant 27 45 38 - - 1C AS1 

savannah sparrow 

Passerculus 

sandwichensis Small Migrant - 2 1 - - 1B -

Scott's oriole Icterus parisorum Small Resident 5 40 10 - - 1C AS1 

western scrub-jay Aphelocoma californica Small Resident 1 - - - - 1C AS1 

18 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 3. Summary of Individuals of Sensitive Species Detected by Survey Type Including Size Classification and Status (continued) 

Species Common 

Name 

Species Scientific 

Name 

Size 

Class 

Resident 

Classification 

Total Number Detected 

USFWS 

Status1 

BLM 

Status2 

State 

Status3 

Species of 

Continental 

Importance4 Point 

Counts 

Songbird 

Migration Incidental 

white-crowned sparrow Zonotrichia leucophrys Small Resident - 12 84 - - 1C -

white-throated swift Aeronautes saxatalis Small Resident 1 - 9 - - 1C WL2 

1. USFWS 2008 Birds of Conservation Concern (BCC) for Bird Conservation Region 33 (Sonoran and Mojave Deserts) 

2. 2010 BLM Sensitive species 

3. Tiers of Species of Greatest Conservation Need (revised 2010) from the Arizona State Wildlife Action Plan 

1A Considered vulnerable in at least one of the 9 categories, or is federal endangered, threatened or candidate species; is covered under a signed conservation agreement; or is 

petitioned for listing
 

1B Considered vulnerable but matches none of the additional criteria above
 

1C Unknown vulnerability status species
 

4. Partners in Flight 2004 North American Landbird Conservation Plan Species of Continental Importance 

WL2 Watch List Species—Moderately abundant or widespread with declines or high threats 

WL3 Watch List Species—Restricted distribution or low population size 

AS1 Additional Stewardship Species—High percent of Global Population in single biome (breeding or winter) 

19 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Thirty-one bird species were identified during 143, 10-min songbird migration surveys, with an 

average of 2.94 species observed per 10-min survey. Mean use across all points for all bird 

species combined was 6.62 observations/10-min survey. Among all bird types, mean use was 

highest for passerines (5.83 birds/plot/10-min survey). Within passerines, black-throated 

sparrow (2.48 birds/plot/10-min survey), cactus wren (0.65), and Brewer’s sparrow (0.57), were 

the species with the highest mean use. Cumulatively, two species (black-throated sparrow and 

cactus wren) comprised 41.9 percent of all observations. Both of these species are considered 

resident breeders in the Project area and neither is assigned special status by state or federal 

agencies (Appendix A). All other species made up less than 10 percent of the observations 

individually. 

Two bird groups showed greater use of washes compared to ridges; the grassland 

birds/sparrows (i.e., Brewer’s sparrow, black-throated sparrow, chipping sparrow, horned lark, 

lark bunting, sage sparrow, savannah sparrow, song sparrow, unidentified sparrow, and whitecrowned sparrow) and swifts/hummingbirds (i.e., Costa’s hummingbird and unidentified 

hummingbird). Although the grassland birds/sparrows showed significantly greater use of 

washes, the overall tendency for songbirds was for no selection of washes. Additionally, use by 

swifts/hummingbirds, although considered statistically different between washes and ridges, 

was based on very low use estimates (0.0 and 0.045 observations/100-m plot/10-min survey at 

ridge and wash points, respectively). The songbird migration survey data support the hypothesis 

that the Project area is primarily used by resident breeding bird species, and is not a high-use 

stopover site for migrating songbirds as only five migrant species were detected. 

2.3 Golden Eagle Nest Surveys 

Golden eagle nest surveys were conducted in 2011 and 2012. To protect the locations of this 

sensitive species, breeding area locations are shown with 1-mile-square (1.6-km-square) 

buffers on maps of both surveys. In 2011, WEST (Thompson 2011) conducted aerial golden 

eagle nest surveys following the survey protocol outlined in the Interim Golden Eagle Inventory 

and Monitoring Protocol (Pagel et al. 2010). The initial survey was conducted on March 9 and 

10, 2011; a time when golden eagles in this part of Arizona were likely to be initiating nesting or 

already incubating eggs. A second survey was conducted on April 21, 2011 to document nest 

productivity and to verify the status of all nests located during the initial survey. Between the first 

and second survey, the Project area footprint changed such that there was a small area 

encompassed within the 10-mile (16-km) buffer that was not surveyed by WEST during the 

initial flight (9.5-10 miles [15-16 km] from the Project area in the extreme southwest portion of 

the search area; Figure 4). However, nesting data from this area for early in the season were 

provided by an AZGFD survey of the area in late February 2011. 

In 2012, a two-phase nest survey was conducted to determine occupancy of the known golden 

eagle breeding areas identified in 2011 within 10 miles (16 km) of the Project area and to 

estimate the productivity of any active nests (Tetra Tech 2012). The survey approach was 

developed by an inter-agency group consisting of representatives of AZGFD, BLM, 

Reclamation, and the USFWS during a meeting on November 9, 2011. Phase 1 of the nest 

survey was conducted from the ground (per agency recommendation) on January 14-17, 2012 

to determine breeding area occupancy for the five breeding areas within 5 miles (8 km) of the 

20 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 4. 2011 Golden Eagle Breeding Area Locations* and Status 

*Breeding areas are shown using 1-mile buffers around nest locations to protect the sensitive nature of eagle nest 

locations 

21 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 5. 2012 Golden Eagle Breeding Area Locations* and Status 

*Breeding areas are shown using 1-mile buffers around nest locations to protect the sensitive nature of eagle nest 

locations 

22 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Project area (Figure 5). Each Phase 1 survey consisted of a 4-hour observation period within 

sight of a known nest or group of nests. Phase 2 consisted of two helicopter flights conducted 

by the American Eagle Research Institute (AERI). AERI conducted the first flight on March 10, 

2012. During this flight, AERI checked all known nests identified during 2011 surveys within 10 

miles (16 km) of the Project area that were outside of wilderness or proposed wilderness areas 

(Figure 5). One known breeding area located in a BLM wilderness area was surveyed from the 

ground on April 12, 2012 so that it would not be necessary to fly over the wilderness area. On 

April 29, 2012, a second flight was conducted under the conditions of a permit issued by the 

National Park Service to survey known nests located within proposed wilderness areas of the 

Lake Mead National Recreation Area (Figure 5). During this survey, AERI also checked the 

status of all nests surveyed on March 10. Focal nest observations of four hours in length were 

performed weekly from May 25 – June 15, 2012 at each of the two active nests identified within 

and nearest the Project area (i.e., Highway 93 and Squaw Peak, Figure 5). 

Occupancy of breeding areas and nests for this document is defined according to the Arizona 

Golden Eagle Survey and Monitoring Protocol (Southwestern Golden Eagle Management 

Committee [SGEMC] 2011). These definitions are consistent with Pagel et al. (2010), but use 

the term ‘breeding area’ in place of ‘territory’: 

Breeding Area: An area containing one or more nests within the range of one mated pair of 

birds. 

Occupied Breeding Area: An occupied Breeding Area must have a nest where at least one of 

the following activity patterns was observed during the breeding season: 

a.	 Young were raised. 

b.	 Eggs were laid. 

c.	 One adult sitting low in the nest, presumably incubating. 

d.	 Two adults present on or near the nest. 

e.	 One adult and one bird in immature plumage at or near a nest, if mating behavior was 

observed (display flight, nest repair, copulation). 

f.	 A recently repaired nest with fresh sticks, or fresh boughs on top, and/or droppings 

and/or molted feathers on its rim or underneath. 

Unoccupied Breeding Area: A nest or group of alternate nests at which none of the activity 

patterns diagnostic of an occupied Breeding Area were observed in a given breeding season. 

Active Nest: A nest in which eggs have been laid. Activity patterns (a), (b), and (c) above are 

diagnostic of an active nest. 

It is not uncommon for a pair of eagles to occupy a nest in years when resources are scarce, yet 

never lay eggs; these nests are still considered occupied (USFWS 2011a). Assigning an 

unoccupied stick nest to a species is challenging because a nest might be used by different 

species in each year and the characteristics of nests overlap for some species. However, 

golden eagle nests can usually be distinguished from hawk, falcon, and raven nests by size and 

placement. 

23	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

2.3.1 2011 Golden Eagle Nest Survey Results 

Thirty-six potential golden eagle nests, representing 16 breeding areas, were documented at 26 

locations (multiple alternate nests at some locations) in the Project area plus 10-mile-radius (16­

km-radius) survey area during the 2011 golden eagle nest survey (1 unoccupied breeding area 

in Project area, all other breeding areas outside Project area, see Table 4). No occupied 

breeding areas were documented within the Project area. None of the nests in these breeding 

areas were active (Figure 4). Because golden eagles often have multiple alternate nests within 

a single breeding area, the number of golden eagle nests and locations found is not reflective of 

the number of golden eagle breeding areas. Within the Project area plus 10-mile-radius survey 

area, WEST or AZGFD considered two of the golden eagle breeding areas outside of the 

Project area occupied. One breeding area was considered occupied by WEST due to the 

presence of a pair of adult golden eagles near a cluster of seven nests located approximately 

nine miles (14.5 km) south of the southernmost turbine string (Table 4, Figure 4). AZGFD 

considered a second breeding area occupied due to the presence of a pair of golden eagles 

during their February 2011 survey flight in the vicinity of nests 9.5-10 miles (15-16 km) to the 

southwest of the Project area (Figure 4). WEST did not check these nests during the second 

survey, and therefore could not confirm whether this breeding area was occupied. 

The remaining unoccupied breeding areas contained nests that ranged from 0.7 miles (1.1 km) 

to 10.5 miles (16.9 km) from the nearest turbine corridor (Table 4, Figure 4). These nests did not 

have evidence of occupancy during the 2011 survey and no additional historical data exists to 

determine recent use (McCarty and Jacobson 2011). One raptor nest not included in the total 

count of golden eagle nests was located on a transmission tower and is a historical golden 

eagle nest site (based on data from the Arizona Heritage Data Management System [HDMS] 

2012). The transmission tower nest was occupied by red-tailed hawks in 2008 and 2009; nest 

status was unknown in 2010 and BLM reported that the nest was again occupied by red-tailed 

hawks in 2011 (Thompson 2011). 

2.3.2 2011 Raptor Nests 

During the course of eagle nest surveys, five non-eagle nest sites were documented within 

approximately 0.6 miles (about one km) of the proposed turbine corridors. Thompson (2011) 

stated that these nests were likely red-tailed hawk nests; however, birds were only seen on 

three of the five nests. Most of the nests (4) were in Joshua trees and one was on a 

transmission line tower. The transmission tower nest is a historical golden eagle nest site based 

on data from the Arizona HDMS (2012), as described above in Section 2.3.1. Thompson (2011) 

also reported a newly built, active red-tailed hawk nest in 2011 that was identified by the BLM 

on a transmission tower. 

2.3.3 2012 Golden Eagle Nest Survey Results 

A total of 89 golden eagle nests were detected at an estimated 16 golden eagle breeding areas 

in the Project area plus 10-mile-radius survey area (1 breeding area in Project area, 15 outside 

Project area) including one previously undocumented breeding area (Black Mountains South, 

Figure 5, Table 5). Eight breeding areas were classified as occupied, with five of those breeding 

areas containing one active nest each. The remaining eight breeding areas were classified as 

unoccupied. In general, eagle pairs in temperate regions remain on their breeding areas yearround, but may not be present at the nest cliff during survey visits unless they are tending eggs 

24 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 4. 2011 Golden Eagle Nest Data Collected by WEST for the Mohave County Wind 

Farm and 10-mile Survey Buffer (Thompson 2011) 

Nest 

ID 

Date 

Located 

Nest 

Status1 

Nest 

Condition2 

Nest 

Substrate 

# Nests 

at 

Location 

Breeding Area 

Breeding 

Area 

Status3 

0 3/9/2011 Inactive Good Cliff 3 Detrital Wash Occupied 

1 3/9/2011 Inactive Bad Cliff 2 Detrital Wash Occupied 

2 3/9/2011 Inactive Good Cliff 1 Detrital Wash Occupied 

3 3/9/2011 Inactive Good Cliff 4 Table Mountain Unoccupied 

4 3/9/2011 Inactive Good Cliff 1 Senator 

Mountain Unoccupied 

5 3/9/2011 Inactive Good Cliff 1 Senator 

Mountain Unoccupied 

6 3/9/2011 Inactive Good Cliff 1 Squaw Peak Unoccupied 

7 3/9/2011 Inactive Good Cliff 3 Squaw Peak Unoccupied 

8 3/9/2011 Inactive Bad Cliff 1 Squaw Ridge 

North Unoccupied 

10 3/9/2011 Inactive Good Cliff 1 Squaw Ridge 

North Unoccupied 

11 3/9/2011 Inactive Good Cliff 1 Gypsum Ledges Unoccupied 

12 3/9/2011 Inactive Good Cliff 1 Gypsum Ledges Unoccupied 

13 3/9/2011 Inactive Good Cliff 1 Gypsum Ledges Unoccupied 

14 3/9/2011 Inactive Good Cliff 1 Gypsum Ledges Unoccupied 

16 3/9/2011 Inactive Good Cliff 1 Temple Bar Unoccupied 

17 3/9/2011 Inactive Bad Cliff 1 Temple Bar Unoccupied 

18 3/9/2011 Inactive Good Cliff 1 Temple Bar Unoccupied 

20 3/9/2011 Inactive Good Cliff 2 Salt Spring Unoccupied 

22 3/9/2011 Inactive Good Cliff 1 Virgin Canyon Unoccupied 

26 3/9/2011 Inactive Good Cliff 1 Golden Rule 

Ridge Unoccupied 

28 3/9/2011 Inactive Good Cliff 1 Black Mountains 

North Unoccupied 

29 3/10/2011 Inactive Good Cliff 2 Highway 93 Unoccupied 

30 3/10/2011 Inactive Good Cliff 1 Wilson Ridge Unoccupied 

31 3/10/2011 Inactive Good Cliff 1 Detrital Wash Occupied 

32 4/21/2011 Inactive Good Cliff 1 Great West 

Mine Unoccupied4 

33 4/21/2011 Inactive Good Cliff 1 Great West 

Mine Unoccupied4 

1. Status based on evidence of occupancy in current year (e.g., fresh nest materials, presence of adults or young). 

2. Condition based on presence of a well-defined nest structure and intact nest materials. 

3. One of the additional breeding areas (AGFD 9) surveyed by AZGFD in February, and not included here, was 

occupied. 

4. Unoccupied breeding area status based on combined data from AZGFD (February survey) and WEST (April survey, 

Thompson 2011). 

25 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 5. 2012 Golden Eagle Nest Data for the Mohave County Wind Farm and 10-mile Survey Buffer (Tetra Tech 2012) 

Breeding Area 

Phase 1 Phase 2 

Breeding 

Area Status 

Nest 

Ground-based Survey Status 

1/14-1/17/2012 

Aerial Survey – Flight 1 

03/10/2012 

Aerial Survey – Flight 2 

04/29/2012 

Highway 93 

Occupied, adult observed 

perched and flying around 

nest site 

Active, adult incubating Active, 3-week-old chick in nest Occupied Active 

Great West Mine Not surveyed Unknown, no signs of 

occupancy at known nests Active, 3.5-week-old chick in nest Occupied Active 

Detrital Wash Not surveyed Occupied, fresh nest 

lining and mute Active, 3-week-old chick in nest Occupied Active 

Table Mountain Not surveyed Occupied, fresh nest 

lining Occupied, fresh nest lining Occupied Inactive 

Senator Mountain Unoccupied, no recent sign of 

occupancy at known nests 

Unoccupied, no signs of 

occupancy at known nests 

Unoccupied, no signs of occupancy at 

known nests Unoccupied Inactive 

Squaw Peak Unoccupied, no recent sign of 

occupancy at known nests 

Occupied, fresh nest 

lining and mute Active, adult brooding 1-3-day-old chick Occupied Active 

AGF4 

Nest documented by 

Thompson 2011 no longer 

present 

Cliff nest found near 

location of historic nest ­

Unoccupied, no signs of 

occupancy at nest 

Unoccupied, no signs of occupancy at 

nest Unoccupied Inactive 

Black Mountains 

North Not surveyed Not surveyed Unoccupied, known nest occupied by 

red-tailed hawk Unoccupied Inactive 

Black Mountains 

South Not surveyed Not surveyed Unoccupied, no signs of occupancy at 

two newly documented nests Unoccupied Inactive 

Squaw Ridge North Occupied, fresh mute on front 

of nest Not surveyed Occupied, greenery in nest and mute 

on back wall Occupied Inactive 

Gypsum Ledges Not surveyed Not surveyed Occupied, lots of mute Occupied Inactive 

Temple Bar Not surveyed Not surveyed Active, two 4.5-week-old chicks in nest Occupied Active 

Salt Spring Not surveyed Not surveyed Unoccupied, no signs of occupancy at 

known nests Unoccupied Inactive 

26 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 5. 2012 Golden Eagle Nest Data for the Mohave County Wind Farm and 10-mile Survey Buffer (Tetra Tech 2012) (continued) 

Breeding Area 

Phase 1 Phase 2 Breeding 

Area Status 

Nest 

Status Ground-based Survey 

1/14-1/17/2012 

Aerial Survey – Flight 1 

03/10/2012 

Aerial Survey – Flight 2 

04/29/2012 

Virgin Canyon Not surveyed Not surveyed Unoccupied, no signs of occupancy at 

known nest Unoccupied Inactive 

Golden Rule Ridge Not surveyed Not surveyed Unoccupied, no signs of occupancy at 

known nest Unoccupied Inactive 

Wilson Ridge 

Unoccupied, single known 

nest occupied by red-tailed 

hawk1 

Not surveyed Not surveyed Unoccupied Inactive 

1. Ground-based survey conducted on 4/12/2012. 

27 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

or young. Unoccupied breeding areas may become occupied in subsequent breeding seasons, 

and breeding pairs in occupied breeding areas may not lay eggs every year. Therefore, it is 

possible that breeding areas lacking active nests in 2011 and 2012 could contain active nests in 

the future. 

The five active nests were located in the following breeding areas: Highway 93, Squaw Peak, 

Temple Bar, Detrital Wash, and Great West Mine (Figure 5). There was at least one nestling in 

each active nest and a minimum of six young in total at the five nests on April 29, 2012. Ages of 

observable young ranged from 3 days to 4.5 weeks (Table 5). Focal nest observations at the 

Highway 93 and Squaw Peak active nests did not detect any eagle movements in or near the 

nests for four consecutive weeks (May 21 – June 15), indicating that young in these nests did 

not likely survive to fledging. Success of the four nestlings at the Temple Bar, Detrital Wash and 

Great West Mine active nests was unknown after the last observation on April 29, 2012; 

however, they are assumed to have been successful to derive maximum productivity estimates. 

Mean productivity at the five active nests was 0.8 young, assuming that the four unknown-status 

nestlings successfully fledged. Mean population productivity for the 10-mile radius survey area 

was 0.50 fledglings per occupied breeding area assuming that the four nests with unknownproductivity status nestlings fledged. These values are lower than the mean population 

productivity for temperate latitudes (0.87 fledglings per occupied breeding area; Kochert et al. 

2002). 

The Squaw Peak breeding area was the only breeding area documented within the Project area 

(Figure 5) and it contained an active nest. Ground surveyors first determined that the nest was 

active on April 23, 2012 when an incubating female was observed on the nest. Active status of 

the nest was confirmed during the aerial survey on April 29, 2012 when an adult was observed 

brooding at least one, 1-3 day-old nestling. The body of the female obscured the contents of the 

nest, so the exact number of young could not be determined. However, focal nest observations 

on May 31, 2012 indicated that the nest had likely failed. 

3 RISK ASSESSMENT 

The following sections describe risks to golden eagles at the Project area (Alternative A), with 

additional details provided for California condor and all other bird species. The risk assessment 

uses Alternative A (maximum of 283 turbines) as a worse-case scenario to analyze potential 

impacts to golden eagles, California condors, and other birds. 

3.1 Collision 

3.1.1 Golden Eagles 

The collision risk analysis uses a weight-of-evidence approach to estimate the risk of eagle 

fatalities at the Project. BP Wind Energy has performed focused surveys of golden eagle flights 

to document the use of space by eagles breeding in and moving through the Project area and 

its vicinity, and has used these data to inform the risk assessment in combination with nestlocation information. The subsections that follow describe a quantitative fatality projection using 

the model from the Draft ECP Guidance (USFWS 2011a), a summary of the results of nest 

surveys as they relate to collision risk, a comparative analysis of other western wind projects 

that have pre-construction eagle use data and post-construction eagle fatality data, and a 

28 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

qualitative analysis of the availability of orographic (mountain generated) updrafts within the 

Project area based on topography and prevailing winds, which may increase the risk near 

certain topographic features by concentrating eagle use near the RSA. 

3.1.1.1 USFWS Fatality Model 

The USFWS model as described in the Draft ECP Guidance (USFWS 2011a) assumes that risk 

of collision is proportional to use, and that use is distributed evenly across the study area (i.e. 

the model does not account for spatial variation). To estimate the potential number of annual 

fatalities, Tetra Tech used a spreadsheet-based version of the model, which was provided to 

Tetra Tech by USFWS in April 2012 (version: October 2011; E. Bjerre, USFWS, pers. comm., 

2012). The model used the data on eagle minutes in the RSA available from the point counts, 

described above (Section 2.1), to estimate potential annual golden eagle fatalities. The analysis 

of data from the 2007-2011 avian point counts assumed that each golden eagle sighting within 

the RSA during a 20-minute point count equates to one minute of total time within the RSA; the 

same assumption used by USFWS in its analyses of such data (B. Millsap, USFWS, pers. 

comm., 2011). This assumption was necessary because prior to the release of the Draft ECP 

Guidance in 2011, avian surveyors did not routinely record eagle minutes flying within the RSA. 

The 2012 eagle point count data were recorded during 2-hour point counts, and included direct 

measurements of eagle minutes flying within the Project area at heights corresponding to the 

maximum extent of proposed RSAs (30-150m above-ground) within unlimited radius plots 

(mean radius achieved = 1.6 km). The count protocol recommended in the Draft ECP Guidance 

(USFWS 2011a) uses all eagle minutes below 175 m above ground and within an 800-m fixed 

radius of the count point. Eagle minutes were collected from unlimited radius plots averaging 1.6 

km, larger than those recommended in the Draft ECP Guidance, because eagles are easily 

monitored at distances greater than 800 m within the Project area. Eagle minutes entering the 

quantitative model were limited to those within the range of RSAs, because strikes can only 

occur at those heights; the architecture of the model inherently assumes that any eagle minutes 

entered are those within the hazardous area defined by a rotor radius, and any minutes outside 

of that area therefore inflate the fatality estimate. The rotor radius used for the analysis was 60 

m, slightly larger than the radius of the largest turbine being considered for the Project. 

Point count results were grouped into the 2007/2008, 2010/2011, and 2012 survey periods for 

analysis (see Section 2.0). The USFWS Excel-based model requires the number of 20-minute 

point counts as an input, and when count durations differ among years, it is necessary to 

convert all of the counts to a standard count duration. Thus, because point count duration in 

2012 was longer than in the previous years (2 hours per survey versus 20 min per survey), 

Tetra Tech converted the number of counts (2-hour duration) in 2012 to the equivalent number 

of 20-minute count periods prior to analysis. To incorporate interannual variability in seasonal 

sampling and eagle detections, the sample effort (N) and eagle minutes in the RSA (t) were 

averaged across years for each season. These average seasonal values were then totaled to 

produce an average annual value which was used as the model input (Table 6). 

Sampling was not conducted in the summer because of the harshness of the desert 

environment and the resulting assumption that eagles would not be present during summer 

months. Although summer was not sampled, BP Wind Energy wanted to produce a 

29 December 2012 
 

 

 

 

Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

conservative fatality estimate that assumed some post-construction eagle use of the Project 

area would occur during summer. Tetra Tech therefore interpolated summer eagle minutes by 

Table 6.	 Variables and Constants Used in the Calculation of Potential Eagle Fatalities for 

the Mohave County Wind Farm. 

Symbol 

t 

Name 

Eagle minutes 

Description (Units) 

Minutes of eagle flight detected at RSA height during point 

counts (minutes) 

N Sample effort The number of 20-minute point count periods surveyed 

s Sample duration 

The duration of an individual point count. Because this was 

20 minutes in 2007-2011, and 2 hours in 2012, the 2012 

sample effort (N) was converted to the number of 20-minute 

periods (minutes) 

a Sample area The area sampled by the point counts (km2

) 

E Mean exposure 

minutes 

The mean number of exposure minutes per sample minute in 

the sampled area (eagle minutes/min/km2

) 

h Hazardous area Total area within one rotor radius of all turbines ( km2

) 

T Total daylight hours Total hours of daylight assuming 12-hour per day average 

ε Expansion factor Scaling factor that scales mean exposure minutes to the 

hazardous area (h) and total daylight hours (T). ε = T x h. 

C Average collision 

probability 

The probability that an eagle flying through the RSA of a 

turbine will collide with the turbine 

F Eagle fatalities Estimated eagle fatalities per year 

assuming that sampling effort (N) and eagle minutes in the RSA (t) in summer were the average 

of the values for spring and fall. This assumption is likely conservative because it assumes 

eagles remain in the desert during summer, which they may not do. Mean exposure minutes, 

defined by USFWS as the average number of eagle minutes per minute of sample per square 

kilometer (km2

) (see Table 6 for description of variables), were calculated as: 

Mean exposure minutes (E) =t/N/a/s 

where t was eagle minutes in the RSA, N was the number of point counts, a was the total area 

sampled, and s was the duration of a point count (Table 6). For each survey season, the mean 

exposure minutes were adjusted using an expansion factor (ε) that corrected for the total area 

within one rotor radius of the turbines (hazardous area, h) and the total daylight hours (T) per 

season assuming an average of 12 hours daylight per day. From mean exposure minutes, Tetra 

Tech calculated the estimated annual fatality rate (F) using the expansion factor (ε) and the 

average collision probability (C = 0.0067) calculated from studies in Whitfield (2009) by the 

USFWS using mixture models as: 

Eagle Fatalities (F) = E x ε x C. 

Tetra Tech calculated the estimated annual fatalities for two categories of alternatives described 

in the draft EIS (BLM 2012): Alternative A (maximum of 283 turbines), and Alternatives B and C 

(maximum of 208 turbines). To account for uncertainty due to interannual variation not captured 

by averaging, Tetra Tech constructed an 80 percent upper confidence limit based on a tdistribution (Zar 1996). These values do not account for the 1.25-mile no-build buffer or 

removed turbine strings and are therefore conservative. 

30	 December 2012 
 

 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Alternative A – 283 turbines. Average annual eagle minutes across the three sample years (t 

± SD), equaled 5.75 ± 2.40 minutes. Applying the USFWS model to these data produced a 

mean exposure minute estimate (E) of 0.0035 eagle minutes/hour/km2

. The expansion factor for 

this option (ε) was 14,025.6 hours x km2

. The resulting estimated potential eagle fatalities per 

year (upper 80 percent confidence interval [CI]) based on 283 turbines were 0.33 (0.45) eagle 

fatalities per year. Annual fatality rates corresponding to these estimates would result in 1.65 

(2.25) eagle fatalities over a 5-year period and 9.9 (13.5) eagle fatalities over the anticipated 30­

year life of the Project. 

Alternatives B and C – 208 turbines. Average annual eagle minutes across the three sample 

years (t ± SD), equaled 5.75 ± 2.40 minutes. Applying the USFWS model to these data 

produced an exposure minutes estimate (E) of 0.0035 eagle minutes/hour/km2

. The expansion 

factor for this option (ε) was 10,300.1 hours x km2

. The resulting estimated potential eagle 

fatalities per year (upper 80 percent CI) based on 208 turbines were 0.24 (0.33) eagle fatalities 

per year. Annual fatality rates corresponding to these estimates would result in 1.20 (1.65) eagle 

fatalities over a 5-year period and 7.2 (9.9) eagle fatalities over the anticipated 30-year life of the 

Project. 

Caveats and Uncertainties in the Model 

The data used in the model capture more temporal variation than spatial variation. Surveys 

were conducted during 2007/2008, 2010/2011, and 2012. Golden eagle reproductive activity 

varies in relation to weather conditions (e.g., Steenhof at al. 1997). Tetra Tech therefore 

examined weather conditions in these years using the Palmer Drought Severity Index (PDSI) 

which uses temperature and rainfall data to represent the severity of the dry or wet spell (NCDC 

2011). The PDSI varies from -6.0 to +6.0, with index values between -0.49 and +0.49 

designated “near normal”, and values farther from 0.0 indicating increasing divergence from 

normal conditions. Tetra Tech used the PDSI results to assess how representative weather 

conditions were of “typical” conditions in the area. The time frames sampled at the Project area 

captured eagle activity during a period of moderate to extreme drought (PDSI <-2.0; 2007/2008) 

and of near normal to slightly wet conditions (2010/2011, 2012; NCDC 2011; Figure 6). With 

respect to spatial variation, the surveys conducted in 2007/2008 captured eagle use in the 

northeastern section of the proposed Project area whereas the 2010/2011 data captured eagle 

use in the northwestern section of the proposed Project area, and the 2012 surveys covered the 

entire Project area including the previously unsurveyed southern portion. Surveys in 2012 

documented two active eagle nests and associated movements within or immediately near the 

Project area, and these observations are reflected in the fatality estimate. 

Golden eagle use of the Project area likely varies based on the number of active golden eagle 

nests in the Project area and its vicinity. The number of active breeding areas has been shown 

to be driven by prey availability (Bates and Moretti 1994, Steenhof et al. 1997, McIntyre and 

Adams 1999) and weather conditions prior to the nesting season (i.e., severity of winter; 

Steenhof et al. 1997). In Idaho, Marzluff et al. (1997) found that some eagles responded to low 

prey density by using larger areas; however, some eagles maintained small territories and 

focused on alternate prey when preferred prey was scarce. In desert populations, Bittner and 

Meador (2011) have interpreted long-term drought conditions as a driver of low eagle 

productivity, although Lightfoot et al. (2011) did not find a correlation between rainfall and rabbit 

31 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

abundance. Tetra Tech reviewed the PDSI to evaluate the nest surveys of 2011 and 2012 in the 

context of drought. Based on the PDSI for northwest Arizona, the area was under severe 

drought conditions in 2009; however, precipitation conditions were near normal to slightly wet in 

2010 and 2011 and near normal in early 2012 (Figure 6; PDSI values are -1.9 to +1.9). The 

greater breeding activity in 2012 within the Project area and 10-mile radius versus 2011, despite 

the similar conditions, suggests that conditions other than regional moisture levels may be 

driving reproductive effort. 

Extreme Drought 

Severe Drought 

Mild Drought 

Near Normal 

Incipient Dry Spell 

Moderate Drought 

* PDSI values: -4.0 or less (Extreme Drought), -3.0 to -3.9 (Severe Drought), -2.0 to -2.9 (Moderate Drought), -1.0 to 

-1.9 (Mild Drought), -0.5 to 0.9 (Incipient Dry Spell), -0.49 to +0.49 (Near Normal), +0.5 to +0.9 (Incipient Wet 

Spell),+1.0 to +1.9 (Slightly Wet), +2.0 or +2.9 (Moderately Wet), +3.0 or +3.9 (Very Wet), +4.0 or above (Extremely 

Wet). 

Figure 6.	 Palmer Drought Severity Index for Northwest Arizona from January 2000 to April 

2012* 

3.1.1.2 Nest Survey Data 

Golden eagle nest surveys conducted in 2011 and 2012 indicated the presence of 16 golden 

eagle breeding areas (8 occupied in 2012) in the Project area plus 10-mile-radius survey area (1 

within Project area, 15 outside Project area), comprising 89 potential golden eagle nests (5 

containing young in 2012). Among the 89 nests were 16 alternate nests considered to be part of 

the Squaw Peak breeding area. These observations suggest that the Project may potentially 

present risks to breeding eagles and their young from collision with turbines. Distances of active 

eagle nests within the Project area to the nearest turbine siting corridors are considered in detail 

in the disturbance/displacement section (Section 3.3.1), but nest proximity may also potentially 

32	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

influence risk of collision for some individuals. As a conservative avoidance and minimization 

measure, BP Wind Energy will implement a no-build buffer within 1.25 miles (2 km) of the 2012 

active Squaw Peak nest and the currently known alternate nests within that breeding area. This 

buffer increased the ranges of distances between the turbine siting corridors and the nearest 

active nest from 0.3-0.9 miles (0.5-1.5 km) to 1.3 miles (2.0 km) depending on the development 

alternative. It should be noted that the only known-fate survival study of golden eagles 

associated with a wind farm, conducted at Altamont Pass, California, suggests that proximity to 

nests is less important than individual flight behavior in predicting risks of collision and 

electrocution (Hunt 2002). 

3.1.1.3 Comparison of Western Wind Projects 

As a third line of evidence, Tetra Tech examined existing, publicly available data for wind projects 

west of the Mississippi River that have information available concerning both pre-construction eagle 

use and post-construction fatality monitoring results. Tetra Tech found a total of 15 studies from four 

western states meeting these criteria (Figure 7). The pattern of fatalities and activity levels at these 

projects suggests that eagle fatalities are low when mean use by eagles is <0.05 eagles/20 minutes 

(0.15 eagles/hour), which is consistent with the threshold for predicting low risk of fatalities stated in 

the USFWS Region 2 ECP checklist (USFWS 2011b). The overall mean use at the Project area 

2007-2012 was 0.02 eagles/20 minutes, and the eagle fatality rate for the Project area is therefore 

likely to be low if use equates to risk. The variation in fatality rates, however, indicates that there is 

not a simple, linear relationship between use and fatalities. Some projects with high mean use 

experience low numbers of fatalities, whereas other projects with comparable or lower use have 

experienced greater numbers of fatalities indicating that site-specific differences are important. 

Additionally, because these studies do not share identical methodologies (e.g., radius of avian use 

survey plots, fatality search intervals), and there is variance associated with time a given facility was 

monitored (range: 1-3.5 years), comparisons of eagle use and fatalities represent generalizations 

only. 

33 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

0 

0.05 

0.1 

0.15 

0.2 

0.25 

0.3 

0.35 

0.4 

0 

0.25 

0.5 

0.75 

1 

1.25 

1.5 

1.75 

2 

Golden eagle use/20 min/year

Golden eagle fatalities/MW 

Number of fatalities 

Total golden eagle fatalities 

Golden eagle use/20 min/year 

Total golden eagle fatalities/MW 

Figure 7. Mean Use by Golden Eagles (Eagle Use/20 min; Pre-construction), Total Golden 

Eagle Fatalities, and Total Golden Eagle Fatalities/MW (Post-construction) at 15 

Wind Energy Projects in the Western U.S. Compared to Mean Use at Mohave 

County Wind Farm (Value Circled in Red). 

3.1.1.4 Qualitative Analysis of Winds and Topography 

One of the primary risk factors identified in the Draft ECP Guidance (USFWS 2011a) is the 

interaction of topographic features and wind to create favorable conditions for slope soaring or kiting 

(stationary or near-stationary flight using headwinds) in the vicinity of turbines. Slope soaring is 

typically favored by conditions that produce orographic (mountain caused) updrafts; these conditions 

include the upwind side of steep slopes and those oriented perpendicular to prevailing winds. 

Additionally, the Draft ECP Guidance suggests that saddles and low-lying areas between peaks 

may be riskier than other features. 

Topography of the Project area is varied with steep ridges, gentle slopes, and flat areas (primarily in 

the southwestern portion) divided by valleys of variable widths (Figure 8). Elevations within the 

Project area range from approximately 585 to 1169 m (1,920 to 3,836 feet) above sea level 

indicating that there is notable topographic relief. 

Tetra Tech examined the slope and aspect of proposed turbine siting corridors to assess the 

existence of risk factors associated with slope soaring, kiting, saddles and low-lying areas (Figures 8 

and 9). After the removal of turbines within the 1.25-mile no-build buffer, most areas within the 

proposed turbine siting corridors are on low to moderate slopes with the exception of two corridors 

in the northeastern portion of the Project area (Figure 8). These corridors incorporate moderate to 

high slopes in some portions of the corridors, but they are generally set back from the steepest 

slopes. Aspects within the turbine siting corridors are primarily east-northeast and west-southwest 

whereas prevailing winds within the Project area are south to south-southwest and north to north34 December 2012 
 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

northeast (Figure 9). Assuming that the greatest potential for orographic updrafts as described 

above occurs on steep slopes oriented from south to south-southwest or north to north-northwest, 

risks to eagles are probably highest along the ridge in the northwestern portion of the Project area, 

the short, parallel ridges in the eastern portion of the Project area and the low hills in the westcentral portion of the Project area. This suggests that most of the proposed turbine siting corridors 

will have relatively low risk to eagles with the exception of corridors near these features; however, 

the no-build buffer within 1.25 miles (2 km) from the known Squaw Peak nests removed the turbine 

siting corridors from the northwestern portion of the Project area, thus minimizing risk to eagles. 

3.1.1.5 Weight of Evidence Conclusions 

The weight of evidence from the combination of quantitative and qualitative analysis for golden 

eagles suggests that there is a low risk to eagles from the Project overall. Some eagle fatalities 

(≤1.0 per year) are predicted by the quantitative analysis before the application of advanced 

conservation practices, and the qualitative analyses support the conclusion that the rate of 

fatalities will be low. The use of the Project area by golden eagles appears to be lower than the 

other project in the region with publicly available data (Perrin Ranch Wind Energy Facility, 

Coconino County, AZ), which recorded 60 eagle minutes over a survey period similar to the 

2012 surveys of the Project area. Despite the higher rate of eagle use, Perrin Ranch estimated 

a similar annual eagle fatality rate (0.014-0.59 eagles per year, depending on estimation 

method) to that calculated for the Project (mean = 0.24-0.33, depending on development 

alternative), due primarily to the smaller number of turbines at Perrin Ranch. 

35 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 8. Slope (in Degrees) of Land within the Mohave County Wind Farm 

36 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 9. Aspect of Land Surface within the Mohave County Wind Farm 

37 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

3.1.2 California Condor 

On December 12, 2011, the USFWS provided an evaluation of federally listed threatened or 

endangered species known to occur in Mohave County and the potential to be affected by the 

Project. In this evaluation, the USFWS agreed with the BLM’s initial determination that there 

were no federally listed threatened or endangered species, and/or critical habitat would be 

affected by the Project with the rationale that they currently do not occur in the area. The 

USFWS identified concerns about potential impacts to the non-essential population of California 

condor. Additionally, the USFWS was contacted on December 16, 2010 about the potential for 

California condors to utilize the Project area. On that date, the USFWS provided information 

through the Peregrine Fund that California condors have been moving their use away from the 

Project area for about a decade (USFWS 2010, BLM 2012). Although current telemetry shows 

that condors do not use the Project area, they are a wide-ranging species that can travel long 

distances and may expand beyond their current range during the life of this Project. Therefore, 

there is the potential for the species to occur in the Project area in the future. 

In addition to the avoidance and minimization measures detailed in Sections 4-6, the following 

measures would be implemented to address potential impacts to condors: 

	 Prior to the start of construction, BP Wind Energy will contact the BLM Kingman Field 

Office and the Phoenix office of the USFWS to determine whether recent telemetry 

efforts from the Peregrine Fund indicate California condors have been detected in 

proximity to the Project area. BP Wind Energy will also notify both agencies when 

construction is complete. Once per year during Project operation for the life of the 

project, BP Wind Energy will re-contact both agencies as part of their due diligence to 

determine whether California condors have been sighted in proximity to the Project area. 

	 If a condor occurs at the construction site, construction activities that could result in 

injury to condors would cease until the condor leaves on its own or until techniques are 

employed by permitted personnel that results in the condor leaving the area. 

	 The worker environmental training program will include California condors to educate 

construction and site workers and provide proper guidance about avoiding any 

interaction. In addition, the WEAP will include procedures for notification of both the 

BLM Kingman Field Office and the Phoenix office of the USFWS if condors occur at the 

site during construction. 

	 Non-permitted personnel cannot haze or otherwise interact with condors. 

	 The construction site would be cleaned up (e.g., trash removed, scrap materials picked 

up) at the end of each day that work is being conducted to minimize the likelihood of 

condors visiting the site (see Sections 4-6). 

	 In the event that any large dead animals or carcasses (e.g., cattle, horses, burros) are 

detected by construction or O&M staff, the BLM Kingman Field Office will be notified. No 

further action will be taken unless directed by BLM and consistent with existing laws and 

regulations. 

3.1.3 Other Non-eagle Bird Species 

Birds have been identified as a group at risk from collisions with wind turbines (Erickson et al. 

2005, Drewitt and Langston 2006, Arnett et al. 2007, Strickland et al. 2011). Specifically, 

migrant passerines (e.g., songbirds) are found more often in post-construction fatality 

38	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

monitoring compared to other groups of birds (Arnett et al. 2007). At newer generation wind 

energy facilities outside of California, approximately 60 percent of documented fatalities have 

been songbirds, of which 50 percent are nocturnal migrants, a group which has had the most 

fatalities reported by number among bird species (Erickson et al. 2001a, Johnson and Stephens 

2011, Strickland et al. 2011). It is estimated that less than 0.01 percent of migrant songbirds that 

pass over wind farms are killed, based on radar data and fatality monitoring (Erickson 2007). 

Locally breeding songbirds may experience lower fatality rates than migrants because many of 

these species tend not to fly at turbine rotor heights during the breeding season, in contrast to 

species like nocturnal migrants which typically fly at greater heights and are at risk of collision 

when ascending and descending from nightly migration flights (Young et al. 2007). However, 

some breeding songbird species have behaviors that increase their risk of collisions with 

turbines (e.g., horned lark, Erickson et al. 2004, Kerlinger et al. 2006b). 

The habitat conditions and results of the on-site avian surveys for the Project area suggest there 

are no major concentrations of non-eagle bird species during the breeding season or during 

migration (Thompson et al. 2011a). Black-throated sparrow, common raven, horned lark, and 

turkey vulture comprised over 50 percent of all avian observations within the Project area during 

point count surveys. Avian use of the Project area peaked in the spring (0.97 large birds/20 min, 

2.33 small birds/20 min), with lower use in the winter and fall for both size classes. A total of 64 

species were detected at the Project area during point counts, songbird migration surveys, and 

incidental observations, 54 of which were potential residents (Appendix A). Of the individual 

birds detected during point counts (excluding incidentals), 86.7 percent were of the 31 resident 

species detected. Songbird migration surveys detected 31 species, of which 5 were migrants, 

and results of the comparison between washes and ridges indicate that the Project area is not a 

high-use stopover area for migrants (Thompson et al. 2011a). It is likely that birds seeking 

standing water for stopover bypass the Project area in favor of Lake Mead. The dominance of 

resident species in the point counts suggests that fatality rates will be low at the Project area. 

This interpretation is reinforced by the dominance of species (with the exception of horned lark) 

that are not commonly reported as fatalities at wind farms. Although horned lark have been 

frequently reported as fatalities at wind facilities (e.g., Young et al. 2003b, Kerlinger et al. 2006b, 

Johnson and Erickson 2011), Project-related fatalities are unlikely to have population impacts 

given the stable population trend within the surrounding Sonoran and Mohave Desert Bird 

Conservation Region (BCR 33, NABCI 2000; Sauer et al. 2011) and the widespread and 

abundant nature of the species (Beason 1995). 

Despite the observation that most avian fatalities at wind farms are songbirds, raptor fatality 

(including eagles) historically has received the most attention. Raptor fatality at newer wind 

projects has been low relative to older-generation wind farms, although there is substantial 

regional variation in raptor fatality rates (Erickson et al. 2002, 2004; Johnson et al. 2002; Kerns 

and Kerlinger 2004; Jain et al. 2007). Raptors constitute approximately 6 percent of reported 

bird fatalities, but generally have a smaller percentage of birds observed using wind farms 

during pre-construction surveys (Strickland et al. 2011). 

Mean raptor use (including eagles) within the Project area was low (0.23 birds/20 min) in the 

avian point count surveys conducted from 2007-2011 suggesting that raptor fatality will be low if 

use is proportional to risk (Young et al. 2003b, Strickland et al. 2011). Raptor species that are 

found on-site primarily include American kestrel, red-tailed hawk, and turkey vulture. Fatalities of 

39 December 2012 
 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

these species have occurred at wind farms (Kerns and Kerlinger 2004; Erickson et al. 2004), 

and fatality rates appear to be related to abundance (Strickland et al. 2011). Therefore, they are 

the most likely potential raptor fatalities at the Project area. Turkey vulture, in particular, may 

have increased susceptibility to collision because of higher use within the RSA than the other 

raptor species observed. However, risks to raptors appear to be low for the Project because 

topographic features that encourage risky behaviors like slope-soaring and kiting (USFWS 

2011a) are limited and discontinuous (occurring mostly in the northwest portion of the Project 

area) and the majority of those features are associated with the 1.25 mile no-build buffer. In 

addition, use of the Project area by raptors is low (ranked 39th out of 44 facilities based on data 

provided in Thompson et al. [2011a]; note that Thompson et al.’s [2011a] ranking of the Project 

was lower due to exclusion of turkey vultures). Of those raptor species most likely to become 

fatalities (e.g. American kestrel, red-tailed hawk, turkey vulture), turbine-related fatality at the 

Project is unlikely to cause population-level impacts given their widespread and abundant 

nature (Ferguson-Lees and Christie 2001). 

The collision risk for non-eagle birds at the Project will likely be low. This conclusion is based on 

the summary above and information known on collision risk. Nationally reported avian fatality 

rates average 2.43 birds/MW/year and range from 0.15 to 11.02 birds/MW/year (Table 7a). 

Avian fatality rates at facilities in the western U.S. within desert regions (defined as having < 20 

inches [50 cm] annual precipitation; University of California Museum of Paleontology 2012) 

average 2.05 birds/MW/year and range from 0.31 to 3.19 birds/MW/year (Table 7b). For 

subgroups, such as small (≤ 10-inches) birds and large (> 10 inches) birds, fatality rates have 

generally been reported on a per turbine basis. Nationally, small birds including songbirds are 

killed at an average rate of 2.40 small birds/turbine/year (range 0.02-5.70 small 

birds/turbine/year, Table 7a), with a western desert regional average of 2.71 small 

birds/turbine/year (range 0.02-5.70 birds/turbine/year; Table 7b). Large birds (a group including 

raptors, waterfowl, gamebirds, etc.) have an average fatality rate of 0.32 large birds/turbine/year 

nationally (range 0.00-1.19 birds/turbine/year, Table 7a), and 0.43 large birds/turbine/year in the 

western desert U.S. (range 0.02-1.19 birds/turbine/year, Table 7b). 

40 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 7a. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind Facilities Nationally in the U.S. 

Wind Facility, State Region Habitat 

Estimated 

Mean Bird 

Fatality 

/Turbine/Year 

Estimated 

Mean Bird 

Fatality 

/MW/Year 

Estimated 

Raptor 

Fatality 

/Turbine/Year 

Estimated 

Raptor 

Fatality 

/MW/year 

Estimated 

Large Bird 

Fatality 

/Turbine/Year 

Estimated 

Small Bird 

Fatality 

/Turbine/Year 

Ainsworth, NE (Derby 

et al. 2007) Western Mixed grass 

prairie 2.68 1.63 0.10 0.06 0.19 2.48 

Altamont, CA 

(Smallwood and Karas 

2009) 

Western 

Desert 

Agricultural 

cropland - 1.56 1.79 - - -

Big Horn, WA (Kronner 

et al. 2008) 

Western 

Desert 

Mixed grass 

prairie 3.81 2.54 0.23 0.15 - -

Biglow Canyon Phase I 

(2008), OR (Jeffrey et al. 

2009a) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

2.90 1.76 0.06 0.03 0.35 2.55 

Biglow Canyon Phase 

II (2010/2011), OR (Enk 

et al. 2012a) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

5.98 2.60 0.06 0.03 0.28 5.70 

Biglow Canyon Phase 

III (2010/2011), OR (Enk 

et al. 2012b) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

5.25 2.28 0.11 0.05 0.26 4.99 

Blue Sky Green Field, 

WI (Gruver et al. 2009) Eastern Agricultural 

cropland 11.83 7.17 - - - -

Buena Vista, CA 

(Insignia 2009) 

Western 

Desert 

Desert 

grasslands 1.15 1.15 0.44 - - -

Buffalo Gap II, TX 

(Tierney 2009) Western Juniper-oak 

woodlands 0.22 0.15 - - - 0.11 

Buffalo Mountain 

Expanded, Inclusive 

Phases (2005), TN 

(Fiedler et al. 2007) 

Eastern Forest 1.80 1.10 - - - -

Buffalo Mountain 

Phase I (2000-2003), TN 

(Nicholson et al. 2005) 

Eastern Forest 7.27 11.02 - - - -

Buffalo Ridge Phase I 

(1996-1999), MN 

(Johnson et al. 2000) 

Eastern Agricultural 

cropland 0.98 2.86 - - 0.05 0.82 

41 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 7a. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind Facilities Nationally in the U.S. (continued) 

Wind Facility, State Region Habitat 

Estimated 

Mean Bird 

Fatality 

/Turbine/Year 

Estimated 

Mean Bird 

Fatality 

/MW/Year 

Estimated 

Raptor 

Fatality 

/Turbine/Year 

Estimated 

Raptor 

Fatality 

/MW/year 

Estimated 

Large Bird 

Fatality 

/Turbine/Year 

Estimated 

Small Bird 

Fatality 

/Turbine/Year 

Buffalo Ridge Phase II 

(1998-1999), MN 

(Johnson et al. 2000) 

Eastern Agricultural 

cropland 2.27 3.03 - - 0.20 2.00 

Buffalo Ridge Phase III 

(1999), MN (Johnson et 

al. 2000) 

Eastern Agricultural 

cropland 4.45 5.93 - - 0 4.45 

Casselman, PA (Arnett 

et al. 2009) Eastern Forest 4.69 - - - - -

Cedar Ridge (2010), WI 

(BHE Environmental 

2011) 

Eastern Agricultural 

cropland 6.14 - - - - 3.65 

Crescent Ridge, IL 

(Poulton 2010) Eastern Agricultural 

cropland - - - - - -

Diablo Winds, CA 

(WEST 2006) 

Western 

Desert 

Desert 

grasslands 1.19 1.80 0.21 0.32 0.47 0.72 

Dry Lake I, AZ 

(Thompson et al. 2011b) 

Western 

Desert 

Desert scrub 

and grazeland 4.66 2.22 - - - -

Elkhorn Valley, OR 

(Jeffrey et al. 2009b) Western 

Desert 

Dryland 

agriculture and 

grazeland 

1.06 0.64 0.10 0.06 0.31 0.75 

Foote Creek Rim, 

Phase I, WY (Young et 

al. 2003) 

Western 

Desert 

Mixed grass 

prairie 1.50 - 0.03 - 0.02 1.46 

Forward Energy, WI 

(Grodsky and Drake 

2011) 

Eastern Agricultural 

cropland 3.27 2.18 - - - -

High Winds (2003­

2005), CA (Kerlinger et 

al. 2006b) 

Western 

Desert 

Agricultural 

cropland 2.45 1.36 - - - -

Hopkins Ridge, WA 

(Young et al. 2007) 

Western 

Desert 

Agricultural 

cropland 2.21 1.23 0.25 - 0.76 1.45 

Judith Gap, MT (TRC 

Environmental 2008) 

Western 

Desert 

Agricultural 

cropland 4.52 3.01 0.14 - 0.69 3.83 

42 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 7a. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind Facilities Nationally in the U.S. (continued) 

Wind Facility, State Region Habitat 

Estimated 

Mean Bird 

Fatality 

/Turbine/Year 

Estimated 

Mean Bird 

Fatality 

/MW/Year 

Estimated 

Raptor 

Fatality 

/Turbine/Year 

Estimated 

Raptor 

Fatality 

/MW/year 

Estimated 

Large Bird 

Fatality 

/Turbine/Year 

Estimated 

Small Bird 

Fatality 

/Turbine/Year 

Kewaunee County, WI 

(Howe et al. 2002) Eastern Agricultural 

cropland 1.29 1.95 - - - -

Klondike II, OR (NWC 

and WEST 2007) Western 

Desert 

Dryland 

agriculture and 

grazeland 

4.71 3.14 0.17 0.11 0.25 4.46 

Klondike III Phase 1, 

OR (2007-2009), OR 

(Gritski et al. 2010) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

5.65 3.19 0.27 0.15 0.78 4.86 

Klondike IIIa Phase 2 

(2008-2010), OR (Gritski 

et al. 2011) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

4.20 2.80 0.09 0.06 1.19 3.01 

Klondike Phase I, OR 

(Johnson et al. 2003) Western 

Desert 

Dryland 

agriculture and 

grazeland 

1.42 0.95 0 - 0.26 1.16 

Maple Ridge (2008), NY 

(Jain et al. 2009) Eastern Agricultural 

cropland 3.42 2.07 - - 0.08 3.07 

Mars Hills (2008), ME 

(Poulton 2010) Eastern Forest 2.04 1.36 - - - -

Moutaineer, WV (Kerns 

and Kerlinger 2004) Eastern Forest 4.04 2.69 - - - -

Nine Canyon, WA 

(Erickson et al. 2003a) 

Western 

Desert 

Agricultural 

cropland 3.59 - 0.065 - 0.28 3.31 

San Gorgonio Phase I 

and Phase II, CA 

(Anderson et al. 2005) 

Western 

Desert 

Desert 

grasslands 0.04 - 0.003 - 0.02 0.02 

Stateline (2001-2003), 

OR/WA (Erickson 2004) Western 

Dryland 

agriculture and 

grazeland 

1.93 - 0.06 - 0.23 1.70 

Stateline (2006), 

OR/WA (Erickson et al. 

2007) 

Western 

Dryland 

agriculture and 

grazeland 

0.81 1.23 0.07 - 0.18 0.63 

43 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 7a. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind Facilities Nationally in the U.S. (continued) 

Wind Facility, State Region Habitat 

Estimated 

Mean Bird 

Fatality 

/Turbine/Year 

Estimated 

Mean Bird 

Fatality 

/MW/Year 

Estimated 

Raptor 

Fatality 

/Turbine/Year 

Estimated 

Raptor 

Fatality 

/MW/year 

Estimated 

Large Bird 

Fatality 

/Turbine/Year 

Estimated 

Small Bird 

Fatality 

/Turbine/Year 

Top of Iowa (2003), IA 

(Jain 2005, Jain et al. 

2011) 

Western Agricultural 

cropland 0.38 0.42 - - - -

Top of Iowa (2004), IA 

(Jain 2005, Jain et al. 

2011) 

Western Agricultural 

cropland 0.76 0.84 

Tuolumne (Windy 

Point), WA (Enz and 

Bay 2010 as cited in 

Johnson and Erickson 

2011) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

- 3.20 - 0.29 - -

Vansycle, OR (Erickson 

et al. 2000) Western 

Dryland 

agriculture and 

grazeland 

0.63 - - - 0.13 0.50 

Wild Horse, WA 

(Erickson et al. 2008) 

Western 

Desert 

Mixed grass 

prairie 2.79 1.55 0.17 0.09 0.48 2.31 

Mean for All Western Facilities 2.56 1.79 0.21 0.12 0.38 2.30 

Range for Western Facilities (NWCC 2010 values) 0.04 – 5.98 0.15 – 3.20 

(0 - 6.3) 0 – 1.79 0.03 – 0.32 (0 – 0.86) 0.02 – 1.19 0.02 – 5.70 

National Mean 3.08 2.43 0.21 0.12 0.32 2.40 

Range for National Facilities (NWCC 2010 values) 0.04 – 11.83 0.15 – 11.02 

(0 – 14.0) 0 – 1.79 0.03 – 0.32 (0 – 0.86) 0 – 1.19 0.02 – 5.70 

44 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 7b. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind Facilities in Desert Regions of the Western U.S. 

Wind Facility, State Region Habitat 

Estimated 

Mean Bird 

Fatality 

/Turbine/Year 

Estimated 

Mean Bird 

Fatality 

/MW/Year 

Estimated 

Raptor 

Fatality 

/Turbine/Year 

Estimated 

Raptor 

Fatality 

/MW/year 

Estimated 

Large Bird 

Fatality 

/Turbine/Year 

Estimated 

Small Bird 

Fatality 

/Turbine/Year 

Altamont, CA (Smallwood 

and Karas 2009) 

Western 

Desert 

Agricultural 

cropland - 1.56 1.79 - - -

Big Horn, WA (Kronner et 

al. 2008) 

Western 

Desert 

Mixed grass 

prairie 3.81 2.54 0.23 0.15 - -

Biglow Canyon Phase I 

(2008), OR (Jeffrey et al. 

2009a) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

2.9 1.76 0.06 0.03 0.35 2.55 

Biglow Canyon Phase II 

(2010/2011), OR (Enk et al. 

2012a) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

5.98 2.6 0.06 0.03 0.28 5.70 

Biglow Canyon Phase III 

(2010/2011), OR (Enk et al. 

2012b) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

5.25 2.28 0.11 0.05 0.26 4.99 

Buena Vista, CA (Insignia 

2009) 

Western 

Desert 

Desert 

grasslands 1.15 1.15 0.44 - - -

Diablo Winds, CA (WEST 

2006) 

Western 

Desert 

Desert 

grasslands 1.19 1.8 0.21 0.32 0.47 0.72 

Dry Lake I, AZ (Thompson 

et al. 2011b) 

Western 

Desert 

Desert scrub 

and grazeland 4.66 2.22 - - - -

Elkhorn Valley, OR 

(Jeffrey et al. 2009b) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

1.06 0.64 0.10 0.06 0.31 0.75 

Foote Creek Rim, Phase I, 

WY (Young et al. 2003) 

Western 

Desert 

Mixed grass 

prairie 1.5 - 0.03 - 0.02 1.46 

High Winds (2003-2005), 

CA (Kerlinger et al. 2006b) 

Western 

Desert 

Agricultural 

cropland 2.45 1.36 - - - -

Hopkins Ridge, WA 

(Young et al. 2007) 

Western 

Desert 

Agricultural 

cropland 2.21 1.23 0.25 - 0.76 1.45 

Judith Gap, MT (TRC 

Environmental 2008) 

Western 

Desert 

Agricultural 

cropland 4.52 3.01 0.14 - 0.69 3.83 

Klondike Phase I, OR 

(Johnson et al. 2003) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

1.42 0.95 0 - 0.26 1.16 

45 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 7b. Estimates of Mean Bird Fatalities per Turbine and per Megawatt at Wind Facilities in Desert Regions of the Western U.S. 

(continued) 

Wind Facility, State Region Habitat 

Estimated 

Mean Bird 

Fatality 

/Turbine/Year 

Estimated 

Mean Bird 

Fatality 

/MW/Year 

Estimated 

Raptor 

Fatality 

/Turbine/Year 

Estimated 

Raptor 

Fatality 

/MW/year 

Estimated 

Large Bird 

Fatality 

/Turbine/Year 

Estimated 

Small Bird 

Fatality 

/Turbine/Year 

Klondike II, OR (NWC and 

WEST 2007) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

4.71 3.14 0.17 0.11 0.25 4.46 

Klondike III Phase 1, OR 

(2007-2009), OR (Gritski et 

al. 2010) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

5.65 3.19 0.27 0.15 0.78 4.86 

Klondike IIIa Phase 2 

(2008-2010), OR (Gritski et 

al. 2011) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

4.20 2.80 0.09 0.06 1.19 3.01 

Nine Canyon, WA 

(Erickson et al. 2003a) 

Western 

Desert 

Agricultural 

cropland 3.59 - 0.07 - 0.28 3.31 

San Gorgonio Phase I 

and Phase II, CA 

(Anderson et al. 2005) 

Western 

Desert 

Desert 

grasslands 0.04 - <0.01 - 0.02 0.02 

Tuolumne (Windy Point), 

WA (Enz and Bay 2010 as 

cited in Johnson and 

Erickson 2011) 

Western 

Desert 

Dryland 

agriculture and 

grazeland 

- 3.2 - 0.29 - -

Wild Horse, WA (Erickson 

et al. 2008) 

Western 

Desert 

Mixed grass 

prairie 2.79 1.55 0.17 0.09 0.48 2.31 

Mean for Western Facilities in Desert Regions 3.11 2.05 0.23 0.12 0.43 2.71 

46 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Risk of bird fatalities at the Project is expected to be lower than at the average wind farm 

nationally and regionally because of the low abundance and species richness recorded during 

avian surveys. This risk will be further reduced through measures taken during the design, 

construction, and operational phases of the Project (Sections 4-6). Key avoidance and 

minimization measures include a 1.25-mile no-build buffer around the Squaw Peak breeding 

area, construction of above-ground power lines following Avian Power Line Interaction 

Committee (APLIC) guidelines, burial of collection lines where possible, lighting minimization, 

ground disturbance restrictions, and low-impact turbine and met tower design. 

3.2 Electrocution 

Utility lines, particularly distribution lines, can potentially result in electrocution of golden eagles 

because their wing span is large enough that the bird can simultaneously contact two 

conductors or a conductor and grounded hardware (APLIC 2006). Therefore, any structures that 

allow for circuit completion (i.e., flesh-to-flesh contact between energized parts or an energized 

and grounded part) pose an electrocution risk. To protect birds from possible electrocution, 

APLIC recommends that lines in areas with eagles have a horizontal separation of 60 inches 

(150 cm) and a vertical separation of 40 inches (100 cm) between phase conductors or between 

a phase conductor and grounded hardware. Therefore, the risk of electrocution for the Project is 

likely to be low because the generation interconnection tie line and any collection lines that are 

not buried will follow APLIC guidelines for the design of overhead lines. 

3.3 Disturbance/Displacement 

3.3.1 Golden Eagles 

Golden eagle disturbance or displacement is possible during construction or operation of the 

Project. The potential for displacement or disturbance for eagles is somewhat offset by the 

baseline disturbance in the Project area which includes recreational uses such as backpacking, 

wildlife viewing, horseback riding, hunting, primitive camping, hiking, mountain biking, and offroad vehicle (ORV) use; daily tourist helicopter overflights; and livestock grazing operations. 

Project construction may disturb golden eagles if they are nesting within line-of-sight of the 

Project or if the areas under active construction are preferred foraging areas. Project operations 

may disturb golden eagles if the presence of the operational turbines causes golden eagles to 

avoid using the Project area. However, evidence of fatalities at other wind farms suggests that 

golden eagles do not avoid operational facilities (Pagel et al. 2011). 

Few studies have been conducted with respect to raptor nest densities and activity before and 

after project construction, and most of these studies have produced descriptive, rather than 

experimental, data. Several studies conducted at western wind energy facilities produced 

somewhat equivocal results, but generally suggest that wind energy facilities do not displace 

nesting raptors or reduce nest densities over the long term (Howell and Noone 1992; Erickson 

et al. 2003a, 2004; Johnson et al. 2000b, 2003; Young et al. 2006, 2010; Gritski et al. 2008). For 

example, post-construction studies at the Leaning Juniper Wind Farm in Oregon suggest that 

raptor nests > 0.5 miles (0.8 km) from turbines were not disturbed by the facility (Gritski et al. 

2008). Other studies have found no clear relationship between nest occupancy and distance 

from turbines (Johnson et al. 2003, Young et al. 2006), and some have suggested that species 

differ in their response to construction activities (Johnson et al. 2000b; Erickson et al. 2003a, 

47 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

2004). It is necessary to look outside the western U.S. to find a before-after/control impact study 

of avian use. Such a study was conducted at the Buffalo Ridge wind-energy facility in 

Minnesota, and it found evidence that northern harriers (Circus cyaneus) avoided turbines in the 

first year following construction. Two years following construction, however, no large-scale 

displacement was detected (Johnson et al. 2000a). 

Based on the 2012 nest survey, there are 16 golden eagle breeding areas in the Project area 

plus the 10-mile-radius search area, one within the Project area and 15 outside the Project area 

(Figure 5). Eight of the breeding areas were occupied in 2012 (as determined by the presence 

of adult eagles in the vicinity of a nest), and five of these were active (i.e. contained eggs, 

young, or incubating adults at the time of the survey). The Squaw Peak occupied breeding area 

is within the northwestern portion of the Project area; all other documented occupied breeding 

areas are outside the Project area up to 10 miles (16 km) from the outer boundary of the Project 

area. Because the Squaw Peak breeding area is within the Project area and was occupied in 

2012 (although not in 2011), and the next closest breeding areas to the Project area (AGF4 and 

Senator Mountain) were unoccupied in 2011 and 2012, the discussion of disturbance as it 

relates to nests is focused on the Squaw Peak breeding area. 

In 2012, the Squaw Peak active nest was on the west side of the ridge, with the ridge blocking 

views eastward out of the nest. Prior to establishing a 1.25-mile (2 km) no-build buffer, under 

Alternative A, the Squaw Peak active nest in 2012 was 0.3 miles (0.5 km) from the nearest 

turbine siting corridor. With the 1.25-mile buffer in place there are no turbine siting corridors 

west of the ridge and the nearest turbine siting corridors are located to the east of the ridge is 

1.3 miles (2.0 km) away (Figure 1). Similarly, under Alternatives B and C, the Squaw Peak 

active nest in 2012 is 0.9 miles (1.5 km) from the nearest turbine siting corridor without the 

buffer, but the nearest turbine siting corridor with the buffer in place is 1.3 miles (2.0 km) east of 

the ridge. With the no-build buffer in place the distance to the nearest turbine siting corridor 

exceeds that of any publicly available buffer distance recommended for avoiding disturbance to 

golden eagles (0.3-1.6 km [0.2-1.0 miles]; Olendorff and Zeedyk 1978, Call 1979, Fuller in Suter 

and Joness 1981, Howard in Suter and Joness 1981, Woffinden in Suter and Joness 1981, 

Suter and Joness 1981, Holmes et al. 1993). Additionally, nest disturbance will be minimized 

through the implementation of avoidance and minimization measures during siting, construction 

and operations (see Sections 4-6), as well as implementation of a 1.25 mile no-build buffer 

around the Squaw Peak breeding area and a curtailment program during the first five years of 

operation based on the 5-year term of the permit (see Section 8.9). Eagle breeding activity 

varies from year to year, and occupancy of breeding areas in the future cannot be predicted. 

3.3.2 Non-eagle Bird Species 

In addition to fatality associated with wind farms, concerns have been raised that some bird 

species may avoid areas near turbines after the wind farm is in operation (Drewitt and Langston 

2006). For example, at the Buffalo Ridge wind energy facility in Minnesota, densities of male 

songbirds were lower in Conservation Reserve Program (CRP) grasslands containing turbines 

than in CRP grasslands without turbines. The authors suggested that the reduced density may 

be due to avoidance of turbine noise and maintenance activities, and to reduced habitat quality 

from the presence of access roads and gravel pads surrounding the turbines, although none of 

these factors were examined in the study (Leddy et al. 1999). Reduced abundance of grassland 

48 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

songbirds was found within 50 m of turbine pads for a wind farm in Washington and Oregon, but 

the investigators attributed displacement to the direct loss of habitat or reduced habitat quality 

and not the presence of the turbines (Erickson et al. 2004). Research at two sites in North and 

South Dakota (Shaffer and Johnson 2008) suggests that certain grassland songbird species 

(two of four studied) may avoid turbines by up to 200 m. None of these studies have addressed 

whether these avoidance effects are temporary (i.e., the birds may habituate to the presence of 

turbines over time) or permanent. 

Construction activities and the presence of turbines and other Project features may disturb or 

displace birds. The impacts to birds from disturbance or displacement from the Project are likely 

to be short-term and limited to distances of 200 m or less (Leddy et al. 1999, Drewitt and 

Langston 2006, Shaffer and Johnson 2008). Pearce-Higgins et al. (2012) found little evidence 

for a post-construction decrease for ten species of birds at wind projects in upland habitats in 

the United Kingdom. However, disturbance related effects were detected during construction. 

The risk of disturbance/displacement will be further reduced through avoidance and 

minimization measures taken during the design, construction, and operational phases of the 

Project (Sections 4-6). Key measures include minimizing disturbance impacts and 

implementation of an Integrated Reclamation Plan and Noxious Weed Management Plan as 

required by BLM. 

3.4	 Habitat Fragmentation 

Habitat fragmentation can exacerbate the problem of habitat loss for birds by decreasing patch 

area and increasing edge habitat. Habitat fragmentation can reduce avian productivity through 

increased nest predation and parasitism and reduced pairing success of males (Robinson et al. 

1995). However, the construction of the Project is not likely to significantly increase the degree 

of habitat fragmentation of the area because the wind farm is located on habitat that is already 

fragmented due to roads, trails, and multiple uses within the area. The majority of the Project 

falls within the low value (i.e., highly fragmented) category in the Habimap unfragmented areas 

model (AZGFD 2012a). Potential habitat fragmentation resulting from the Project will be 

reduced through avoidance and minimization measures taken during the design, construction, 

and operational phases of the Project (Sections 4-6). Key measures include minimizing 

disturbance impacts and implementation of an Integrated Reclamation Plan and Noxious Weed 

Management Plan. 

4	 PROJECT PLANNING AND DESIGN AVOIDANCE AND MINIMIZATION 

MEASURES 

This section identifies impact avoidance and minimization measures that have been or shall be 

incorporated into planning and design for the Project. This section first describes no-build areas 

and describes measures outlined in the EIS. Parallel measures considered during construction 

and operations are described in Sections 5 and 6, respectively. 

Regardless of alternative selected, BP Wind Energy has committed to implementing a no-build 

buffer within 1.25 miles (2 km) of the Squaw Peak golden eagle nests documented in preconstruction studies. As a result, no turbines or any other Project-related infrastructure will be 

constructed within 1.25 miles (2 km) of the nests. BP Wind Energy has also committed to not 

49	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

constructing turbines in two township-range sections in the vicinity of Squaw Peak (Sections 20 

and 21 in T29N, R20W). These no-build areas would result in avoidance and minimization of 

impacts to golden eagles due to the reduction of turbines in the vicinity of nests. 

Both Alternatives B and C reduce the maximum number of turbines to 208 by removing turbines 

from the northwestern (Alternative B) edge or southern edge (Alternative C) of the Project area 

but differ in the location of the turbine strings (BLM 2012). Either development alternative would 

result in potential avoidance and minimization of impacts to golden eagles and other avian 

species due to the reduction in turbine numbers and the 1.25-mile no-build buffer. 

This section identifies Best Management Practices (BMPs) as identified in Appendix B of the 

Draft EIS: 

	 The area disturbed by installation of meteorological towers (i.e., footprint) shall be kept 

to a minimum. 

	 Meteorological towers shall not be located in sensitive habitats or in areas where 

ecological resources known to be sensitive to human activities are present. Installation 

of towers shall be scheduled to avoid disruption of wildlife reproductive activities or other 

important behaviors. 

	 Meteorological towers installed for site monitoring and testing shall be inspected
 

periodically for structural integrity.
 

	 The Project shall be planned to utilize existing roads and utility corridors to the maximum 

extent feasible, and to minimize the number and length/size of new roads, lay-down 

areas, and borrow areas. If new roads are necessary, they shall be designed and 

constructed to the appropriate standard. 

	 BP Wind Energy shall review existing information on species and habitats in the vicinity 

of the Project area to identify potential concerns. 

	 BP Wind Energy shall conduct surveys for federal and/or state-protected species and 

other species of concern (including special status plant and animal species) within the 

Project area and design the Project to avoid (if possible), minimize, or mitigate impacts 

to these resources. 

	 BP Wind Energy shall identify important, sensitive, or unique habitats in the vicinity of 

the Project and design the Project to avoid (if possible), minimize, or mitigate impacts to 

these habitats (e.g., locate the turbines, roads, and ancillary facilities in the least 

environmentally sensitive areas; i.e., away from riparian habitats, streams, wetlands, 

drainages, or critical wildlife habitats). 

	 The BLM shall prohibit the disturbance of any population of federally listed plant species. 

	 BP Wind Energy shall evaluate avian use of the Project area and design the Project to 

minimize or mitigate the potential for bird strikes (e.g., development shall not occur in 

riparian habitats and wetlands). Scientifically rigorous avian use surveys shall be 

conducted. 

	 Turbines shall be configured by BP Wind Energy to avoid landscape features known to 

attract raptors to the greatest extent possible, if site studies show that placing turbines 

there would pose a significant risk to raptors. 

	 BP Wind Energy shall determine the presence of active raptor nests (i.e., raptor nests 

used during the breeding season). Measures to reduce raptor use at the Project area 

50	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

(e.g., minimize road cuts, maintain either no vegetation or non-attractive plant species 

around the turbines) shall be considered. 

	 A habitat restoration plan shall be developed to avoid (if possible), minimize, or mitigate 

negative impacts on vulnerable wildlife while maintaining or enhancing habitat values for 

other species. The plan shall identify revegetation, soil stabilization, and erosion 

reduction measures that shall be implemented to ensure that all temporary use areas 

are restored. The plan shall require that restoration occur as soon as possible after 

completion of activities to reduce the amount of habitat converted at any one time and to 

speed up the recovery to natural habitats. 

	 Procedures shall be developed by BP Wind Energy to mitigate potential impacts to special 

status species. Such measures could include avoidance, relocation of Project facilities or 

lay-down areas, and/or relocation of biota. 

	 Facilities shall be designed to discourage their use as perching or nesting substrates by 

birds, where practicable. Met tower design represents a trade-off. The safest permanent met 

tower design for birds is a lattice-type design, rather than a guyed monopole; a lattice-type 

design met tower may provide some perching opportunities, but it reduces the risk of 

collision presented by guy wires. 

	 If pesticides are used on the site, an integrated pest management plan shall be developed to 

ensure that applications would be conducted within the framework of BLM and Department 

of Interior (DOI) policies and entail only the use of Environmental Protection Agency (EPA)­

registered pesticides. Pesticide use shall be limited to non-persistent, immobile pesticides 

and shall only be applied in accordance with label and application permit directions and 

stipulations for terrestrial and aquatic applications. 

	 “Good housekeeping” procedures shall be developed by BP Wind Energy to ensure that 

during operation the site shall be kept clean of debris, garbage, carrion, fugitive trash or 

waste, and graffiti; to prohibit scrap heaps and dumps; and to minimize storage yards. 

	 BP Wind Energy shall develop a fire management strategy to implement measures to 

minimize the potential for a human-caused fire. 

	 BP Wind Energy shall develop a plan for control of noxious weeds and invasive species, 

which could occur as a result of new surface disturbance activities at the site. The plan shall 

address monitoring, education of personnel on weed identification, the manner in which 

weeds spread, and methods for treating infestations. 

	 An environmental monitoring program shall be developed to ensure that environmental 

conditions are monitored during the construction, operation, and decommissioning phases. 

The monitoring program requirements including adaptive management strategies, shall be 

established at the project level to ensure that potential adverse impacts of wind energy 

development are mitigated. The monitoring program shall identify the monitoring 

requirements for each environmental resource present at the site, establish metrics against 

which monitoring observations can be measured, identify potential mitigation measures, and 

establish protocols for incorporating monitoring observations and additional mitigation 

measures into standard operating procedures and BMPs. 

51	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

This section identifies mitigation measures that BP Wind Energy has committed to as identified 

in chapter 4 of the Draft EIS: 

	 Minimizing surface area disturbance, controlling erosion, applying dust suppression 

practices, and returning disturbed areas as close as possible to the original condition 

including grade and vegetation. 

	 The Project shall be designed to minimize the use of exterior lighting. External lighting at 

the O&M building shall be minimal with downward-directed lighting. BP Wind Energy 

shall avoid night-lighting for facilities other than mandatory lighting on turbines to 

minimize attracting nocturnal migrant birds. 

	 The permanent met towers shall be a free-standing, lattice-tower design (Figure 10) to 

avoid the collision risk associated with guy wires. 

 Electrical collection lines shall be underground, where feasible, to avoid bird collisions. 

 The new transmission line for the Project shall be marked with bird diverters, which shall 

minimize the potential for bird collisions with the lines, if acceptable to the interconnector 

provider. 

 The turbines used will have a tubular tower and not a lattice structure, to minimize 

perching opportunities for birds. 

This section identifies additional avian impact avoidance and minimization measures that BP 

Wind Energy has committed to: 

	 New utility lines built by BP Wind Energy shall be designed following APLIC (2006) 

guidelines to prevent electrocution. APLIC guidelines include recommended distances 

by which phase conductors should be separated (minimum of 60 inches), or the use of 

perch diverters and/or specifically designed avian protection materials in areas where 

this distance is not feasible (APLIC 2006). Phase covers and/or pole caps shall be used 

on metal poles. Protective covers shall be used for equipment on switch poles if they are 

located in known raptor use areas (e.g., areas where raptor flights have been 

documented in field surveys). 

	 BP Wind Energy will develop an ECP (this document) that follows the Draft ECP
 

Guidance issued by the USFWS in January 2011.
 

52	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 10. Permanent Met Tower Design (Photo from Idaho Falls, Idaho) 

53 December 2012 
5 

Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

CONSTRUCTION PHASE AVOIDANCE AND MINIMIZATION MEASURES 

This section identifies wildlife impact avoidance and minimization measures that shall be 

incorporated during construction of the Project. This section describes no-build areas and 

avoidance and minimization measures outlined in the EIS. Parallel measures considered during 

siting and operations are described in Sections 4 and 6, respectively. 

Regardless of alternative selected, BP Wind Energy has committed to implementing a no-build 

buffer within 1.25 miles (2 km) of the Squaw Peak golden eagle nests documented in preconstruction studies. As a result, no turbines or any other Project-related infrastructure will be 

constructed within 1.25 miles (2 km) of the nests. BP Wind Energy has also committed to not 

constructing turbines in two township-range sections in the vicinity of Squaw Peak (Sections 20 

and 21 in T29N, R20W). These no-build areas would result in avoidance and minimization of 

impacts to golden eagles due to the reduction of construction and disturbance in the vicinity of 

nests. 

This section identifies BMPs as identified in Appendix B of the Draft EIS: 

 The area disturbed by construction and operation of the Project (i.e., footprint) shall be 

kept to a minimum. 

 The number and size/length of roads, temporary fences, lay-down areas, and borrow 

areas shall be minimized. 

 Topsoil from all excavations and construction activities shall be salvaged and reapplied 

during reclamation. 

	 In accordance with the habitat restoration plan, all areas of disturbed soil shall be 

reclaimed using weed-free native grasses, forbs, and shrubs. Reclamation activities 

shall be undertaken as early as possible on disturbed areas. 

	 Electrical collector lines shall be buried where feasible in a manner that minimizes 

additional surface disturbance (e.g., along roads or other paths of surface disturbance). 

Overhead lines may be used in cases where burial of lines would result in further habitat 

disturbance or where burial of lines is not feasible. 

	 Guy wires on permanent meteorological towers shall be avoided; however, they may be 

necessary on temporary meteorological towers installed during site monitoring and 

testing. 

	 As a part of worker environmental training, all construction employees shall be instructed 

to avoid harassment and disturbance of wildlife, especially during reproductive (e.g., 

courtship and nesting) seasons. In addition, pets shall not be permitted on-site during 

construction. 

	 Project personnel and contractors shall be instructed and required to adhere to speed 

limits commensurate with road types, traffic volumes, vehicle types, and site-specific 

conditions, to ensure safe and efficient traffic flow and to reduce wildlife collisions and 

disturbance. 

 BP Wind Energy shall develop a fire management strategy to implement measures to 

minimize the potential for a human-caused fire. 

 Erosion, stormwater runoff, and transport of sediment and other contaminants shall be 

minimized through implementation of a stormwater pollution prevention plan, which shall 

54	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

be developed as a requirement of the construction stormwater permit required for the 

Project. 

	 If pesticides are used on the site, an integrated pest management plan shall be 

developed to ensure that applications would be conducted within the framework of BLM 

and DOI policies and entail only the use of EPA-registered pesticides. Pesticide use 

shall be limited to non-persistent, immobile pesticides and shall only be applied in 

accordance with label and application permit directions and stipulations for terrestrial 

and aquatic applications. 

	 BP Wind Energy shall develop a plan for control of noxious weeds and invasive species, 

which could occur as a result of new surface disturbance activities at the site. The plan 

shall address monitoring, education of personnel on weed identification, the manner in 

which weeds spread, and methods for treating infestations. 

	 A habitat restoration plan shall be developed to avoid (if possible), minimize, or mitigate 

negative impacts on vulnerable wildlife while maintaining or enhancing habitat values for 

other species. The plan shall identify revegetation, soil stabilization, and erosion 

reduction measures that shall be implemented to ensure that all temporary use areas 

are restored. The plan shall require that restoration occur as soon as possible after 

completion of activities to reduce the amount of habitat converted at any one time and to 

speed up the recovery to natural habitats. 

	 A monitoring program shall be developed to ensure that environmental conditions are 

monitored during the construction, operation, and decommissioning phases. The 

monitoring program requirements including adaptive management strategies, shall be 

established at the project level to ensure that potential adverse impacts of wind energy 

development are mitigated. The monitoring program shall identify the monitoring 

requirements for each environmental resource present at the site, establish metrics 

against which monitoring observations can be measured, identify potential mitigation 

measures, and establish protocols for incorporating monitoring observations and 

additional mitigation measures into standard operating procedures and BMPs. 

This section identifies mitigation measures that BP Wind Energy has committed to as identified 

in chapter 4 of the Draft EIS: 

 Conduct vegetation clearing during the non-breeding bird season. 

 If the bird breeding season cannot be avoided, conduct bird nest surveys in areas to be 

cleared and flag a non-disturbance area to avoid destroying active nests. 

	 Restricting travel within the Project area to the roads developed for the Project and 

enforcing posted speed limits on those roads to minimize the generation of dust. The 

magnitude of the limits would be based on the localized soil stability conditions and 

would not exceed 25 miles per hour (mph) (40 kilometers per hour). 

	 Develop and implement a spill prevention, control and countermeasures (SPCC) Plan 

that outlines procedures to prevent the release of hazardous substances into the 

environment, thereby avoiding water resource contamination. The SPCC Plan would 

include containment measures that would be implemented in areas where chemicals, 

fuel, and oil are stored. Spill response kits containing items such as absorbent pads 

would be located on equipment and in the on-site temporary storage facilities to respond 

to accidental spills. 

55	 December 2012 
6 

Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

	 All noise-producing equipment and vehicles using internal combustion engines would be 

equipped with exhaust mufflers, air-inlet silencers where appropriate, and any other 

shrouds, shields, or other noise-reducing features in good operating condition that meet 

or exceed original factory specification. Mobile or fixed “package” equipment (e.g., arcwelders, air compressors) would be equipped with shrouds and noise control features 

that are readily available for that type of equipment. 

	 All mobile or fixed noise-producing equipment used on the Project, which is regulated for 

noise output by a local, state, or Federal agency, would comply with such regulation 

while in the course of Project activity. 

	 The Project will comply with all applicable federal, state and Mohave County
 

requirements with respect to noise levels during construction and operation.
 

	 Avoid or minimize impacts on burrowing owls by following AZGFD Burrowing Owl 

Project Clearance Guidance for Landowners (AZGFD 2009), to survey for burrowing 

owls and to institute the appropriate conservation measures for burrowing owls that 

occupy burrows in or near the construction footprint. 

OPERATIONAL PHASE AVOIDANCE AND MINIMIZATION MEASURES 

This section summarizes measures that shall be taken to avoid and minimize impacts to wildlife 

during long-term operation of the Project. Additional details on the specific avoidance and 

minimization measures related to post-construction fatality monitoring are provided in Section 7, 

and details related to operational mitigation and monitoring are provided in Section 8. Parallel 

measures considered during siting and construction are described in Sections 4 and 5, 

respectively, from the BMPs and mitigation measures already committed in the Draft EIS. 

The primary avoidance and minimization measures BP Wind Energy has committed to during 

operations include: 1) a 1.25 no-build buffer around the Squaw Peak breeding area, 2) a 

curtailment zone for the first 5 years of operations that extends beyond the no-build buffer to 

account for the expected spatial use of eagles when the breeding area is occupied, 

corresponding to the 5-year duration of an eagle take permit, 3) three different types of postconstruction fatality monitoring that includes standardized monitoring, responsive monitoring, 

and implementation of the WIRS by operations staff. 

BP Wind Energy voluntarily committed to a multi-year monitoring framework that includes two 

years of standardized post-construction fatality monitoring for all birds; additional responsive 

monitoring as needed; standardized post-construction fatality monitoring in Years 5, 10, 15, 20, 

and 25; eagle behavioral monitoring if an eagle fatality occurs; and incidental monitoring for the 

life of the Project. BP Wind Energy will provide agencies with an annual report each year for the 

life of the Project. See Section 7 for monitoring details. 

Collectively, each of these three categories of avoidance and minimization measures are 

intended to reduce risk and go beyond data collection to inform and shape future actions as part 

of the operational mitigation and adaptive management program detailed in Section 8. 

Specifically, data gathered during the 5-year curtailment program around the no-build buffer and 

curtailment zone will evaluate the effectiveness of the curtailment program to reduce risk of 

collision, as well as potential disturbance to eagles actively nesting in the Squaw Peak area 

(see Section 8.9). In addition, the three types of fatality monitoring are designed to test 

56	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

predictions of use during pre-construction studies against actual fatalities during operations to 

improve risk predictions. Responsive monitoring in particular is expected to be used to detect 

exceedances of thresholds and to identify and correct problems on-site if unexpected levels of 

fatalities are recorded. 

This section identifies BMPs as identified in Appendix B of the Draft EIS: 

	 Inoperative turbines shall be repaired, replaced, or removed in a timely manner. 

Requirements to do so shall be incorporated into the due diligence provisions of the 

rights-of-way authorization. BP Wind Energy shall be required to demonstrate due 

diligence in the repair, replacement, or removal of turbines; failure to do so could result 

in termination of the rights-of-way authorization. 

	 As part of the worker environmental training, employees, contractors, and site visitors 

shall be instructed to avoid harassment and disturbance of wildlife, especially during 

reproductive (e.g., courtship and nesting) seasons. In addition, no pets shall be allowed 

on-site. 

	 A monitoring program shall be developed to ensure that environmental conditions are 

monitored during the construction, operation, and decommissioning phases. The 

monitoring program requirements including adaptive management strategies, shall be 

established at the project level to ensure that potential adverse impacts of wind energy 

development are mitigated. The monitoring program shall identify the monitoring 

requirements for each environmental resource present at the site, establish metrics 

against which monitoring observations can be measured, identify potential mitigation 

measures, and establish protocols for incorporating monitoring observations and 

additional mitigation measures into standard operating procedures and BMPs. 

	 As part of the monitoring program, observations of potential wildlife problems including 

wildlife fatalities, shall be reported to the BLM authorized officer and AZGFD area 

Wildlife Manager for Game Management Unit 15BW. 

	 BP Wind Energy shall develop a fire management strategy to implement measures to 

minimize the potential for a human-caused fire. 

	 “Good housekeeping” procedures shall be developed by BP Wind Energy to ensure that 

during operation the site shall be kept clean of debris, garbage, carrion, fugitive trash or 

waste, and graffiti; to prohibit scrap heaps and dumps; and to minimize storage yards. 

	 Project personnel and contractors shall be instructed and required to adhere to speed 

limits commensurate with road types, traffic volumes, vehicle types, and site-specific 

conditions, to ensure safe and efficient traffic flow and to reduce wildlife collisions and 

disturbance. 

This section identifies mitigation measures that BP Wind Energy has committed to as identified 

in chapter 4 of the Draft EIS: 

	 Restricting travel within the Project area to the roads developed for the Project and 

enforcing posted speed limits on those roads to minimize the generation of dust. The 

magnitude of the limits would be based on the localized soil stability conditions and 

would not exceed 25 mph. 

57	 December 2012 
7 

Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

	 A site-specific worker environmental training program shall be developed and 

implemented throughout the Project operating life. All employees and contractors 

working in the field shall be required to attend the environmental training session prior to 

working on-site. This training shall include information regarding the sensitive biological 

resources, restrictions, protection measures, individual responsibilities associated with 

the Project, and the consequences of non-compliance. 

	 The Project shall be designed to minimize the use of exterior lighting. External lighting at 

the O&M building shall be minimal with downward directed lighting. BP Wind Energy 

shall avoid night-lighting for facilities other than mandatory lighting on turbines to 

minimize attracting nocturnal migrant birds. 

	 Develop and implement a spill prevention, control and countermeasures (SPCC) Plan 

that outlines procedures to prevent the release of hazardous substances into the 

environment, thereby avoiding water resource contamination. The SPCC Plan would 

include containment measures that would be implemented in areas where chemicals, 

fuel, and oil are stored. Spill response kits containing items such as absorbent pads 

would be located on equipment and in the on-site temporary storage facilities to respond 

to accidental spills. 

	 The Project will comply with all applicable federal, state and Mohave County
 

requirements with respect to noise levels during construction and operation.
 

This section identifies additional avian impact avoidance and minimization measures that BP 

Wind Energy has committed to: 

	 BP Wind Energy voluntarily committed to a multi-year monitoring framework that 

includes two years of standardized post-construction fatality monitoring for all birds; 

additional responsive monitoring as needed; standardized post-construction fatality 

monitoring in Years 5, 10, 15, 20, and 25; eagle behavioral monitoring if an eagle fatality 

occurs; and incidental monitoring for the life of the Project. BP Wind Energy will provide 

agencies with an annual report each year for the life of the Project. See Section 7 for 

monitoring details. 

POST-CONSTRUCTION FATALITY MONITORING 

BP Wind Energy will voluntarily conduct three types of standardized post-construction fatality 

monitoring throughout the life of the Project to evaluate the impacts to birds relative to expected 

fatality thresholds (Section 8). First, BP Wind Energy will conduct standardized postconstruction fatality monitoring for the first two years of the project and at 5-year intervals 

thereafter starting with year 5. Second, if estimated fatality rates are greater than the anticipated 

thresholds, additional responsive monitoring will be conducted. Third, BP Wind Energy will also 

conduct incidental monitoring for the life of the Project as part of their Wildlife Incident 

Monitoring System (WIRS). 

Due to the potential for eagle fatalities, additional eagle-specific standardized post-construction 

fatality monitoring will be implemented to expand the area of the Project searched. In addition, 

eagle behavioral studies may be initiated if an eagle fatality occurs. 

58	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

7.1 Initial Post-construction Fatality Monitoring 

BP Wind Energy will conduct standardized post-construction fatality monitoring during the first 

two years following the initiation of Project operations (Table 8). The objective of postconstruction fatality monitoring is to estimate the number of bird fatalities that occur at the 

Project, which is based on the number of carcasses found during carcass searches conducted 

under operating turbines. Both the probability that a carcass persists on-site long enough to be 

detected by searchers (carcass persistence) and the ability of searchers to detect carcasses 

(searcher efficiency) can bias the number of carcasses located during standardized searches. 

Therefore, this post-construction monitoring plan includes (1) methods for conducting 

standardized carcass searches to monitor potential injuries or fatalities associated with Project 

operation; (2) carcass persistence trials to assess seasonal, site-specific carcass persistence 

(due to removal by scavengers or other means); and (3) searcher efficiency trials to assess 

observer efficiency in finding carcasses. Annual Project fatality rates will then be calculated by 

correcting for the bias (i.e., underestimation) due to searcher efficiency and carcass persistence 

time. 

A subset of turbines (20 percent) will be monitored for all birds, with up to an additional 30 

percent monitored specifically for eagle fatalities. The same general technical approach will be 

used for both eagles and non-eagle birds; however, some search parameters (e.g., transect 

width, search interval) will be modified for eagle-only searches in response to increased 

detectability and carcass persistence of eagle carcasses (see Section 7.6.3). Full details of the 

standardized fatality monitoring protocol, including fatality documentation and fatality rate 

estimation, are provided below in Section 7.6. 

7.2 Long-term Fatality Monitoring 

Beginning in Year 5 and every five years thereafter, BP Wind Energy will conduct another year 

of standardized post-construction fatality monitoring following the same approach used during 

the initial monitoring period (Table 8). Long-term monitoring surveys may have reduced level of 

effort for searcher efficiency and carcass persistence trials if the data suggest baseline 

parameters estimated during the initial monitoring period are representative over multiple years. 

Data collected during long-term monitoring will also be used to evaluate previously established 

thresholds (Section 8.3.1). Full details of the standardized fatality monitoring protocol, including 

fatality documentation and fatality rate estimation, are provided below in Section 7.6. 

59 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 8. Post-construction Monitoring Frequency 

Monitoring Year Type Of Standardized Fatality Monitoring Performed WIRS 

Performed 

Year 1 Initial X 

Year 2 Initial X 

Year 3 Responsive, if thresholds exceeded or eagle fatality occurs X 

Year 4 Responsive, if thresholds exceeded or eagle fatality occurs X 

Year 5 Long-term X 

Years 6-9 Responsive, if thresholds exceeded or eagle fatality occurs X 

Year 10 Long-term X 

Years 11-14 Responsive, if thresholds exceeded or eagle fatality occurs X 

Year 15 Long-term X 

Years 16-19 Responsive, if thresholds exceeded or eagle fatality occurs X 

Year 20 Long-term X 

Years 21-24 Responsive, if thresholds exceeded or eagle fatality occurs X 

Year 25 Long-term X 

Years 26-30 Responsive, if thresholds exceeded or eagle fatality occurs X 

7.3 Responsive Monitoring 

Additional post-construction fatality monitoring will occur if an eagle fatality is detected or if the 

designated non-eagle bird fatality thresholds have been exceeded during initial or long-term 

monitoring (Table 8; see Section 8 for types of levels of thresholds and adaptive management). 

Monitoring in these years will focus on the turbine(s) when and where the eagle fatality or 

threshold exceedance occurred; therefore, effort may be reduced in temporal or spatial scales 

(i.e., target seasons instead of entire year or target spatial “hot spots”). As outlined in Section 8, 

BP Wind Energy will identify and attempt to address any eagle fatalities and threshold 

exceedances quickly rather than waiting for the annual report. 

If an eagle fatality occurs, the responsive monitoring will use the methods specified in the 

standardized carcass search protocol for eagles (Section 7.6.3). This monitoring will be focused 

at the turbine where the fatality occurred, and at a minimum of one turbine on either side (east, 

west) within the turbine string. If evidence suggests that a cluster of turbines around the problem 

turbine are equal in collision risk (e.g., similar topography), then the fatality monitoring may be 

expanded to encompass additional turbines. 

7.4 Eagle Behavioral Monitoring 

If an eagle fatality occurs, eagle behavioral surveys may be performed concurrently with fatality 

monitoring. The objective of these behavioral surveys is to gain insight into the cause of the 

fatality and any future risk of eagle collisions. Selection of the areas for behavioral monitoring 

would be based on the location of the fatality and information about eagle use in the area, if 

available. This information would be used to inform additional avoidance and minimization 

measures and adaptive management to reduce the risk of future eagle collisions. 

60 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

7.5 Wildlife Incident Monitoring System 

In addition to the standardized fatality monitoring BP Wind Energy will also implement the WIRS 

(Appendix B), which will start immediately after commercial operation and continue for the life of the 

Project. WIRS is an approach BP Wind Energy uses at all operating facilities to provide a means of 

recording bird species found dead or injured in the Project area by Project staff, thereby increasing 

the understanding of wind turbine and wildlife interactions. WIRS provides a set of standardized 

instructions for Project personnel to follow in response to wildlife incidents in the Project area. Each 

incident will be documented on a data sheet and reported to the designated environmental affairs 

contact. The data will be logged in a tracking spreadsheet maintained by the environmental affairs 

team. Further detail of the protocol can be found in Appendix B. A quarterly review of the reported 

incidents will be undertaken by environmental affairs. This review frequency may be modified based 

on the results of the reporting. The WIRS will be the sole source of fatality monitoring in years 

without standardized fatality monitoring, but will only provide supplemental information in years with 

standardized fatality monitoring (Table 8). 

7.5.1 Training 

Site personnel will be trained to follow WIRS procedure and fill out the WIRS reporting form 

(Appendix C). Additionally, posters identifying BLM Sensitive species and AZGFD SGCN Tier 

1A and 1B species will be prepared and posted at the O&M facility. Training will be performed 

by qualified consultants or in-house environmental staff qualified to conduct the training. 

Training specifics will be described within the environmental monitoring program protocol. 

7.5.2 Reporting 

BP Wind Energy will identify and report any threshold exceedances quickly rather than waiting 

for the annual report. Any incident involving a threatened or endangered bird species or a bald 

or golden eagle will be reported to the USFWS, AZGFD, BLM, and Reclamation (depending on 

location of incident) within 24 hours of detection/discovery of a confirmed threatened, 

endangered, or eagle species. 

Bird casualties discovered by Project staff will be documented and recorded as part of the 

WIRS. This information will be used as a means of tracking impacts to all birds from the Project, 

but will not be used in fatality estimates. Although not specified within BP Wind Energy’s 

standard WIRS protocol, if injured birds are found, the designated AZGFD Wildlife Manager will 

be notified. 

7.6 Standardized Post-construction Fatality Monitoring 

7.6.1 Technical Approach 

The following sections describe the protocol for standardized fatality monitoring. This monitoring 

framework consists of standardized carcass searches conducted at a sample of the Project 

turbines. However, the number of fatalities found during searches represents a minimum 

number of fatalities at a project because not all fatalities that occur are found by observers. 

Therefore, both carcass persistence trials and searcher efficiency trials will be conducted 

concurrently with standardized fatality monitoring to account for the bias attributable to carcass 

removal by scavengers and searcher efficiency. Annual fatality rates (e.g., birds/turbine/year 

and birds/operational MW/year) will then be estimated using statistical methods that adjust the 

61 December 2012 
 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

number of carcasses found for detection biases. Both per turbine and per megawatt estimates 

provide different ways of scaling fatality information to be comparable to other projects. Annual 

fatality rates will be calculated for all bird species combined, small (≤ 10 inches) and large (>10 

inches) birds, raptors, and sensitive species. In some cases, the sample size for a species 

group of interest, such as eagles or other sensitive species, may be too small to allow for the 

calculation of accurate fatality estimates (see Section 7.6.6). In these cases, numerical counts 

of total fatalities detected during standardized and WIRS (see Section 7.5) searches for each of 

these species or species groups will be substituted in place of rate estimates. BP Wind Energy 

believes that these numerical totals will accurately approximate total eagle fatalities at the 

Project because standardized sampling for eagle fatalities will be targeted to areas that field 

surveys have shown to have the highest eagle use; operational (WIRS) searches will also have 

a high probability of detecting eagle fatalities due to the training of personnel and the large size 

of an eagle carcass. Final details of the sampling strategy will be developed in consultation with 

USFWS. 

The field and analytical methods proposed below are consistent with post-construction fatality 

monitoring being conducted, or proposed, for other wind projects elsewhere in the U.S. 

(Johnson et al. 2003; Young et al. 2003; Arnett et al. 2005, 2009; Jain et al. 2007; Huso 2011, 

Strickland et al. 2011). Methods and timing outlined here may be modified over the course of 

the study as Project-specific information is gained to maximize the effectiveness and efficiency 

of the monitoring program (e.g., search interval, number of turbines searched, plot size). The 

standardized post-construction fatality monitoring consists of two components, non-eagle bird 

species monitoring and eagle monitoring (Table 9). 

7.6.2 Standardized Carcass Searches – Non-eagle bird species 

The objective of the non-eagle bird fatality monitoring is to identify the bird species found as 

fatalities at the Project and to statistically estimate fatality rates. This section outlines the 

methods for the standardized carcasses searches, which constitute the initial step in generating 

the fatality estimate (i.e., finding the carcasses under the turbines). These values then will be 

adjusted to account for detection bias (see Section 7.6.6). The methods for standardized 

carcass searches include the sampling duration and intensity, search plot size and 

configuration, and fatality documentation. 

Table 9. Comparison of Non-eagle and Eagle Post-Construction Fatality Sampling Design 

Component 

Turbine section 

Non-eagle 

Random 

Eagle 

Turbines assumed to have higher 

eagle risk based on eagle use 

Percent turbines searched 20 percent Up to 50 percent 

Search plot size 2x maximum blade tip height 2x maximum blade tip height 

Search interval 7-14 days, depending on the season 28 days 

Distance between transects 6 m 12 m 

Searcher efficiency trials Yes Yes 

Carcass persistence trials Yes No 

Method of calculating 

estimated fatalities for the 

Project 

Huso estimator (or other similar 

metric), fatalities per turbine and per 

MW 

Number of eagles found 

62 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

7.6.2.1 Sampling Duration and Intensity 

Standardized post-construction fatality monitoring will consist of standardized searches of 20 

percent of the turbines and will be conducted for the first two years of operation and at 5-year 

intervals (Strickland et al. 2011). To avoid bias in the fatality estimate, turbines will be selected 

in a stratified random manner based on habitat type and topography. To do this, habitat and 

topography will be determined for each turbine location and the sample turbines will be 

randomly selected from the habitat and topography categories in proportion to how often they 

occur in these categories. The same turbines will be searched in both years of the initial 

monitoring period to avoid confounding effects from individual turbines with variation among 

years but in subsequent survey years individual turbine selection may be adaptively managed. 

The survey year will be divided into seasons to allow for the inclusion of season-specific 

searcher efficiency probabilities and carcass persistence times. A search interval of no greater 

than 7 days will be used during spring, summer, and fall to minimize the detection bias 

associated with carcass persistence time for small birds (Strickland et al. 2011). The search 

interval may be adjusted to reduce bias (i.e., the interval between searches may be reduced or 

increased), if needed, based on searcher efficiency and carcass persistence. A search interval 

of 14 days will be used for winter, as the winter sampling period may have lower bird and 

scavenger use (e.g., coyotes, Laundré and Keller 1984). Large birds have longer carcass 

persistence times than small birds; therefore, both search intervals are appropriate for large 

birds (Strickland et al. 2011). 

Seasonal sampling intervals will be as follows: 

	 Spring: March 1 to May 31 – 7-day search interval, approximately 13 searches. 

	 Summer: June 1 to August 15 – 7-day search interval, approximately 11 searches. 

	 Fall: August 16 to November 15 – 7-day search interval, approximately 13 searches. 

	 Winter: November 16 to February 28 – 14-day search interval, approximately 8 

searches. 

7.6.2.2 Search Plot Size and Configuration 

A square search plot centered on the turbine with sides equal to two times the maximum blade 

tip height will be used following the USFWS Land-based Wind Energy Guidelines (USFWS 

2012b) and based on the distance bird carcasses are found from wind turbines at other postconstruction fatality studies (Strickland et al. 2011). Linear transects will be established within 

search plots following the USFWS-recommended distance of approximately 6 m (20 feet) apart 

(USFWS 2012b). This spacing should be adequate for the Project because of the limited ground 

cover within the Project area, but may be adjusted based on actual conditions to maximize 

visual coverage. Searchers will walk along each transect searching both sides out to 3 m (10 

feet) for fatalities during all seasons. 

7.6.2.3 Fatality Documentation 

During the set-up for carcass surveys, a sweep survey will be conducted to remove any 

fatalities that occur before the study is initiated. These carcasses will be documented in the 

same manner as those found during the standardized carcasses searches; however, they will 

63	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

not be included in the statistical analysis because the statistical analysis requires a known 

search interval (i.e., an estimate of when fatalities occurred). 

Searchers will assume that carcasses found are a result of turbine collisions unless the cause of 

death can be clearly attributed to a non-turbine cause. Although an unknown number of fatalities 

may result from natural predation, disease, or anthropogenic events (e.g., shooting), the 

condition of the carcasses when found rarely facilitates determining the cause of death. 

Carcasses found during standardized carcass searches will be labeled with a unique number, 

and species, sex, age, date, time found, location (Global Positioning System [GPS] coordinate, 

and distance/direction from the turbine), condition (e.g., intact, scavenged, feather spot), 

observer, turbine number, and any comments that may indicate cause of death will be collected. 

All carcasses will be photographed in situ. Once documented, carcasses will be marked in a 

standardized fashion (e.g., clipping of primary flight feathers) to indicate they have already been 

recorded. 

Searchers may discover carcasses incidental to standardized carcass searches (e.g., outside of 

a search plot or of a scheduled survey date). For each incidentally discovered carcass, the 

searcher will identify, photograph, and record data for the carcass as would be done for 

carcasses found during standardized scheduled searches, but will code these carcasses as 

incidental discoveries. Incidental discoveries will not enter into the statistical calculation of 

fatality rate for reasons noted above for carcasses found during initial set-up. 

Most native birds in North America are protected under the MBTA and cannot be salvaged 

without a permit from the USFWS. In addition to a federal permit, an Arizona Scientific 

Collecting License is required to handle native wildlife. This plan assumes that bird carcasses 

will be left in place and will not be salvaged unless otherwise directed by the appropriate 

agencies after discovery. 

7.6.3 Standardized Carcass Searches – Eagles 

The objective of eagle-specific fatality monitoring is to determine the number of eagle fatalities, 

if any, at the Project. It is unlikely that the number of eagle fatalities can be statistically 

estimated for the Project because of the anticipated small sample size (see Section 7.6.3.3 for 

additional detail). Therefore, eagle fatalities will be presented as the number of eagle carcasses 

found unless sufficient fatalities occur to also estimate a rate. To maximize the likelihood that 

the eagle fatalities are found, standardized eagle carcass searches will be conducted in addition 

to the standardized non-eagle bird species searches and will focus on areas believed to be of 

higher risk to eagles. If non-eagle bird fatalities are found during eagle searches, data will be 

collected and reported as incidentals because including them in the calculation of the non-eagle 

bird fatality estimate would introduce bias. 

Eagle fatality monitoring methods will follow the same protocol as non-eagle bird species except 

where noted here. 

7.6.3.1 Sampling Duration and Intensity 

In addition to the 20 percent of turbines being searched as part of the non-eagle fatality 

monitoring, up to an additional 30 percent of the Project turbines will be searched following the 

64 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

standardized eagle carcass survey monitoring protocol, for a total of up to 50 percent of Project 

turbines searched. Once the non-eagle search turbines are randomly selected, BP Wind Energy 

will identify the remaining turbines that may be higher risk to eagles based on the preconstruction data. The turbines monitored for eagles will be selected based on known eagle 

locations and suspected risk factors (e.g., proximity to nests, steep slope, aspect, presence of 

saddles, known locations of eagle use: USFWS 2011a). The same turbines will be searched in 

both years of the initial monitoring period to avoid confounding effects from individual turbines 

with variation among years, but in subsequent survey years individual turbine selection may be 

adaptively managed. The remaining turbines that are not searched systematically will be 

monitored by operations staff under BP Wind Energy’s WIRS operational monitoring program 

(see Section 7.5). 

Large birds generally have longer carcass persistence times than small birds and can often be 

in place for longer than 30 days (e.g., NWC and WEST 2004, Gritski et al. 2010). Based on 

these results, the search interval will be initially set at 28 days because of the large size of 

eagles. This interval has been used for other fatality monitoring projects (Oregon EFSC 

2009a,b, 2010, Strickland et al. 2011) where large birds such as eagles are the target of 

monitoring. The 28-day search interval will be compared to the carcass persistence time 

calculated for large birds as part of non-eagle bird fatality monitoring (Section 7.6.4) to ensure 

that the search interval maximizes the likelihood that an eagle fatality will be detected. The final 

search interval will be the shorter of either the lower 90 percent bootstrapped confidence 

interval for carcass persistence trials (Section 7.6.4) or 28 days. 

7.6.3.2 Search Plot Size and Configuration 

Search plot size will follow the non-eagle methods (Section 7.6.2.2). However, based on the 

anticipated higher visibility of an eagle carcass compared to a small bird, linear transects will be 

established within search plots approximately 12 m (40 feet) apart and the searchers will walk 

along each transect searching both sides out to 6 m (20 feet) for fatalities. This transect spacing 

has been used in numerous fatality monitoring studies (e.g., Arnett et al. 2009, Gritski et al. 

2010) and is based on the anticipated higher visibility of an eagle carcass compared to small 

birds. 

7.6.3.3 Fatality Documentation 

Per-turbine eagle fatality estimates likely cannot be generated because these estimates require 

a sample size of at least 5 fatalities (M. Huso, USGS, 2012, pers. comm.). Because the Project 

is not anticipated to have this level of eagle fatalities, the summary of eagle fatalities will likely 

be limited to a count of eagle carcasses found. This count will provide a reasonable estimate of 

the Project-level of eagle fatalities because the sampled turbines will be selected to maximize 

the likelihood of finding an eagle fatality based on the pre-construction data used to evaluate 

risk. Any eagle fatality data collected under BP Wind Energy’s WIRS program (see Section 7.5), 

will also be documented and included in the total. 

7.6.4 Carcass Persistence Trials 

Carcass persistence time estimates the amount of time a carcass remains on-site prior to its 

disappearance from the search area due to scavenging or other means (e.g., due to forces such 

as wind and rain or decomposition beyond recognition). The objective of the carcass 

65 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

persistence trials is to document the length of time carcasses remain in the search area. 

Carcass persistence trials will be conducted in multiple seasons to evaluate seasonal 

differences in carcass persistence (i.e., due to changes in scavenger population density or type) 

and possible differences in the size of the animal being scavenged. 

Carcasses used in the trials will be selected to best represent the size of a range of species. For 

large birds, carcasses may include domestic waterfowl, pheasant, or similar species legally 

obtained from game farms. For small birds, carcasses may include European starlings, house 

sparrows, or other non-native species not legally protected. 

Assuming adequate carcass availability, one carcass persistence trial will be conducted at nonsearched turbines during each of the spring, summer, fall, and winter seasons with at least 15 

carcasses of each bird size class (large bird, small bird) placed per season. Carcass 

persistence trials will not be conducted at eagle monitoring plots because it is assumed that 

carcass persistence values obtained at non-eagle plots are representative. Additionally, carcass 

persistence trials during long-term monitoring may have reduced level of effort if the data 

suggest consistency among years. 

Each carcass used for the carcass persistence trial will be placed randomly within the area 

beneath non-searched turbines. Random locations will be generated and loaded into a GPS as 

waypoints to allow the accurate placement of the carcasses by field personnel. Carcasses will 

be dropped from waist height and allowed to land in a random posture. Each trial carcass will be 

discreetly marked (e.g., small tag or wire wrapped around one leg) prior to dropping so that it 

can be identified as a study carcass if it is found by other searchers or wind facility personnel. 

Personnel will monitor the trial carcasses on days 1, 2, 3, 4, 7, 10, 14, 21, and 30. When 

checking the carcass, searchers will record the condition as intact (normal stages of 

decomposition), scavenged (feathers pulled out, chewed on, or parts missing), feather spot 

(only feathers left), or gone (cannot be found). Changes in carcass condition will be cataloged 

with pictures and detailed notes; photographs will be taken at placement and any time major 

changes have occurred. At the end of the 30-day period, any evidence of carcasses that remain 

will be removed and properly disposed of. 

Estimates of the probability that a carcass persisted between search intervals and therefore was 

available to be found by searchers, will be used to adjust carcass counts for bias using methods 

presented in Huso 2011 or similar analysis method. To date, Huso (2011) presents the most 

bias-free equation for determining the average probability of persistence, which takes into 

account the length of the search interval and the carcass persistence time: 

I / t

ˆ

t

ˆ

(I  e ) rˆ  I 

Where t is the estimated mean persistence time and I is the length of the interval. A 

bootstrapped estimate and 90 percent confidence interval will be calculated based on 5,000 

iterations for carcass persistence time. Bootstrapping is a statistical re-sampling procedure 

where the data are re-sampled with replacement to obtain an estimate and confidence interval. 

66 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

7.6.5 Searcher Efficiency Trials 

The ability of searchers to detect carcasses is influenced by a number of factors including the 

skill of an individual searcher in finding the carcasses, the vegetation composition within the 

search area, and the characteristics of individual carcasses (e.g., body size, color). The 

objective of searcher efficiency trials is to estimate the percentage of bird fatalities that 

searchers are able to find. Estimates of searcher efficiency are then used to adjust carcass 

counts for detection bias. Searcher efficiency trials will be conducted in all seasons to account 

for seasonal differences in searcher efficiency. However, searcher efficiency trials during years 

of long-term monitoring may have reduced level of effort if the data suggest consistency among 

years. Carcass species used in the trials and marking and placement techniques will be the 

same as those in the carcass persistence trials. 

Searcher efficiency trials will begin when standardized carcass searches start. Personnel 

conducting the searches will not know when trials are conducted or the location of the 

efficiency-trial carcasses. Trials will be conducted multiple times throughout each season and 

will incorporate testing of each member of the field crew. Assuming adequate carcass 

availability, at least 15 carcasses of each bird size class (large bird, small bird) will be placed 

per season for searcher efficiency trials. At least 10 carcasses per size and season are needed 

to estimate searcher efficiency. Searcher efficiency trials will be conducted at non-eagle and 

eagle monitoring turbines. The number of carcasses placed prior to the search (i.e., the number 

available for detection during each trial) will be verified immediately after the trial by the person 

responsible for distributing the trial carcasses. Any carcasses not found by searchers will be 

collected after the trial. 

The probability of a carcass being observed is expressed as p, the proportion of trial carcasses 

that are detected by searchers in the searcher efficiency trials. The probability will be estimated 

by carcass size class (large bird, small bird) and season. A bootstrapped estimate and 90 

percent confidence interval will be calculated based on 5,000 iterations for searcher efficiency. 

7.6.6 Fatality Rate Estimation 

To calculate the Project-wide fatality rate (birds/turbine/year and birds/MW/year) and the total 

Project fatalities, BP Wind Energy will use the Huso estimator (Huso 2011) or other appropriate 

statistical methods. The fatality rate can be calculated for large birds, small birds, raptors 

(including eagles), or sensitive species (BLM Sensitive species and AZGFD SGCN Tier 1A and 

1B species) under the following conditions: 

	 At least 5 fatalities within the subgroup are found; and 

	 The 95 percent confidence interval of the Project fatality estimate for all birds at the 

Project lies within two standard deviations (SD) of the mean value for all birds at desert 

region facilities in the western U.S. (Table 7b), indicating that the Project estimate is 

reasonably precise. 

The estimation of fatality rates will incorporate fatalities documented during standardized 

carcass searches adjusted for bias. Specifically, fatality estimates will take into account: 

	 Search interval; 

67	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

	 Observed number of carcasses found during standardized searches during the 

monitoring year for which operation of the facility cannot be ruled out as the cause of 

death; 

	 Carcass persistence, expressed as the probability that a carcass is expected to remain 

in the study area (persist) and be available for detection by the searchers during carcass 

persistence trials; and 

	 Searcher efficiency, expressed as the probability of trial carcasses found by searchers 

during searcher efficiency trials. 

௖೔ೕೖ

̂ The Huso estimator (2011) uses the following equation to estimate fatalities: ݂መ௜௝௞ = ௣ොೕೖכ௥ೕೖכ௩ොೕೖ

category and cijk

th search in the k th turbine during the j th where ݂መ௜௝௞ is the estimated fatality at the i

is the observed number of carcasses at the i

th turbine during the jth search in the kth category. 

The variable ݎ௞௝Ƹ is a function of the average carcass persistence time, which was described 

earlier, and the length of the search interval preceding a carcass being discovered. The variable

ݎ௞௝Ƹ is calculated using the lower value of I, the actual search interval when a carcass is found or 

ǡ෩ܫ

෡ the effective search interval, and is estimated through searcher efficiency trials previously

described. ݒො௝௞ is the proportion of the effective search interval sampled where ݒො= min (1, ܫሚ ܫ(.

Ƹ݌

ǡ

⁄

௝௞ is the estimated probability that a carcass in the kth category that is available to be found will 

be found during the j search. The variables ݌ Ƹ ݎƸ and ݒො௝௞ are assumed not to differ among th

௝௞ǡ ௝௞

turbines but can differ with carcass type, size class, and season. To obtain an estimate of the ೠ

೔సభ∑೙

ೕసభ

೔ ∑మ

ೖసభ௙መ೔ೕೖ where ni is the	 ௧

∑

number of fatalities per turbine the following equation is used: ݂መ=

number of searches at turbine i (i = 1,..., u) and t is the effective number of turbines searched. A 

bootstrapped estimate and 90 percent confidence interval will be calculated based on 5,000 

iterations for the fatality estimate. The 90 percent confidence interval represents the upper and 

lower bounds of the range of fatality rates that has a 90 percent probability of containing the true 

fatality rate. The 90 percent confidence interval is useful in a management context as a means 

of assessing the range of fatality rates that are probable given the number of carcasses that 

were detected. It should be noted that the upper 90 percent confidence limit corresponds to 95 

percent probability that the true fatality rate is lower than the upper 90 percent confidence limit. 

It is anticipated that if eagle fatalities occur, the number of fatalities will be too small (e.g., 5 or 

fewer) for the fatality estimate to be reasonably free of bias. Thus, the raw number of fatalities 

found should represent the total number of Project-related fatalities. The monitoring methods 

were designed to maximize the probability of detecting an eagle fatality, so that numerical 

counts reasonably represent the total number of Project-related eagle fatalities. 

An annual monitoring report will be prepared to summarize non-eagle and eagle fatalities (if 

any) associated with operations of the Project for the life of the Project (See Section 9). In years 

with only WIRS monitoring the report will be limited to details of the fatalities detected (e.g., 

numbers, species identification (when possible), condition, time and date, location). Annual 

reports will be provided to USFWS, AZGFD, BLM, and Reclamation for review. 

68	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

8 MITIGATION AND ADAPTIVE MANAGEMENT 

8.1 Identification of Compensatory Mitigation Approach 

BP Wind Energy asked AZGFD to provide information on causes of eagle fatalities in Arizona 

during a phone call on October 13, 2011 and received the following summary of eagle fatalities: 

1) secondary poisoning (eating carcasses baited to kill coyotes as predator control for livestock), 

2) road and traffic related impacts from carcass scavenging, 3) drowning in stock tanks, 

4) shooting/poaching, and 5) electrocution. BP Wind Energy and Tetra Tech evaluated these 

options, along with the potential of lead abatement as suggested by Dr. Robert Murphy of 

USFWS, to ensure that 1) they were feasible from a business perspective, 2) the USFWS would 

view as acceptable mitigation without being pre-decisional, and 3) without being pre-decisional 

that BLM, Reclamation, and Western would determine that there was sufficient compensatory 

mitigation to sign their respective RODs. Of the options suggested, BP Wind Energy considered 

three of the potential mitigation options as most feasible. These mitigation options included 1) 

roadside carcass search/removal to minimize the chance of eagles being hit by vehicles while 

scavenging on carcasses, 2) contributing to a silent witness poaching reporting system to 

minimize intentional killing of eagles, and 3) prey base improvement off-site to increase the 

habitat quality for eagles. BP Wind Energy then evaluated these options based on their 

acceptability under the BLM IM 2010-156 and the BGEPA and concluded that the roadside 

carcass search/removal best met their requirements. Thus, the mitigation discussion presented 

here focuses on developing a roadside carcass search/removal program. 

The proposed compensatory mitigation strategies outlined in this document represents the first 

attempts to implement carcass search/removal as a means of reducing collisions of eagles 

feeding on roadside carcasses. Although power pole retrofitting has received considerably more 

attention as a mitigation strategy (USFWS 2011a), the USFWS is actively encouraging the 

development of alternative compensation models (such as this proposal for a carcass 

search/removal program) to provide options to applicants from an administrative and feasibility 

perspective. It is BP Wind Energy’s understanding that the USFWS believes a test of carcass 

search/removal as a mitigation strategy will provide valuable data for the overall eagle 

permitting program as well as conservation benefits to eagles, but that such testing may be best 

suited for sites like the Project area that have low eagle use and low projected eagle fatality. As 

such, it is also BP Wind Energy’s understanding that the USFWS will consider flexibility in 

testing new compensatory mitigation strategies like the proposed carcass search/removal 

program in the spirit of broadening the suite of tools and options available to applicants. 

8.1.1 Evidence for Eagle Fatalities Due to Vehicle Collisions 

Vehicle collisions have been identified as a cause of eagle fatalities by a variety of sources 

(Tables 10-12). Data on recent incidental reports of eagle fatalities from the AZGFD for 2000 – 

2011 show that 5 of 24 (21 percent) recorded incidental fatalities collected by AZGFD were due 

to vehicle collisions (Table 10). A review of longer-term records by AZGFD indicated that 12 of 

34 (35 percent) fatalities from 1997-2012 were due to vehicle collisions, including 6 golden 

eagles in 2012 to date, although the agency believes vehicle collision rates to be overestimated 

due to reporting bias that favors roadways (K. Jacobson, AZGFD, 2012, pers. comm.; Table 

10). Of the reports in the public domain across the US, there were 119 records of vehicle 

collisions with golden eagles (Table 11). Public domain sources of vehicle collision data consist 

69 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

of band return records from the United States Geological Survey Bird Banding Lab (Craig and 

Craig 1998, Harmata 2002, USGS 2010), reports to the USFWS National Wildlife Heath Center 

(Philips 1986), and radio telemetry (Hunt 2002). These 119 records represented 5 percent of 

human-related causes of fatalities in golden eagles in the materials reviewed (Tetra Tech 2011). 

Interviews with rehabilitation facilities in Arizona and New Mexico provide additional support that 

golden eagle injuries are regularly occurring as a result of vehicle collisions (Table 12). BP Wind 

Energy also contacted USFWS law enforcement to evaluate if USFWS data can provide 

additional evidence. Law enforcement indicated no data for this purpose are available (N. 

Chavez, 2011, pers. comm.). All of these data except Hunt 2002 were collected incidentally; 

therefore, the true number of eagle fatalities associated with vehicle collisions is likely 

underestimated and higher than presented here. 

Table 10.	 Known Causes of Golden Eagle Fatalities in Arizona from AZGFD 

Cause Year 

<2000 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012* Total 

Lead 1 1 1 1 ** 4** 

Vehicle 

collision 1 1 2 2 6 12 

Electrocution 1 ** 1** 

Other 1 1 4 4 1 3 ** 14** 

TOTAL 2 1 1 2 3 5 4 3 1 3 6** 34 

*As of July 2012 

**Number of non-vehicle golden eagle fatalities in 2012 not provided by AZGFD 

Table 11.	 Golden Eagle Vehicle Collision Data from the Reports, Databases, and Peerreviewed Literature 

Author Years Vehicle 

collision 

Type of 

observation Geographic area Type of 

observation 

Craig and Craig 

1998 1991-1997 1 USFWS band return East-central Idaho Incidental 

Harmata 2002 1977-1999 1 USFWS band return Rocky Mountain 

West Incidental 

Hunt 2002 1998-2001 4 Radio telemetry Altamont Pass, 

California Systematic 

Phillips 1986 1981-1985 100 

Reported to USFWS 

National Wildlife 

Health Center 

Western U.S. Incidental 

Russell and 

Harden 2009 1990-2008 13 Wildlife rehabilitation 

admission New Mexico Incidental 

USGS 2010 1960-2010 23 Band returns All U.S. Incidental 

70	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 12. Golden Eagle Fatalities from Rehabilitation Centers 

Center Eagles per year Primary causes State 

Wild at Heart 1-2 eagles (mostly bald eagles) Lead poisoning, 

aspergillosis Arizona 

Rocky Mountain Raptor 

Program 

~3 bald eagles, ~3 golden 

eagles 

Lead poisoning, 

electrocution, hit by car Colorado 

Liberty Wildlife 

Rehabilitation Foundation 

3-10 eagles per year, species 

vary 

Lead poisoning, gunshot, 

collisions (vehicles, 

turbines) 

Arizona 

8.1.2 Existing Information on Vehicle and Wildlife Collisions 

In general, wildlife collision data is focused on ungulates and collision rates vary among studies 

(Table 13). However, most wildlife collisions occur at night, on paved, unfenced primary roads 

that are open to the public where roads cross migration corridors (Gleason and Jenks 1993, 

Forman and Alexander 1998, Gunther et al. 1998, Kline and Swann 1998, Dussault et al. 2006, 

Grovenburg et al. 2008, McShea et al. 2008, Myers et al. 2008). The experts Tetra Tech 

consulted for input to Section 8.1.3 (see Table 16) unanimously agreed that ungulates and other 

large carcasses are more likely to attract scavenging eagles. For example, coyotes are known 

to be a preferred carrion source, and are commonly used when trapping golden eagles for 

research efforts (B. Millsap, USFWS, 2012 pers. comm.). Unlike small prey items which are 

easily carried away, golden eagles tend to feed on large prey at the kill site because they cannot 

carry items more than 5-7 pounds (2.3–3.2 kilograms) in sustained flight (Palmer 1988, Kochert 

et al. 2002); therefore, eagles tend to remain along roadsides while feeding on large sources of 

carrion. Tetra Tech therefore focused on large carcasses for this literature review. For ungulates 

in particular, most collisions occur during the fall rut in areas where ungulate density is highest 

(Dussault et al. 2006, Bissonette et al. 2008, Grovenburg et al. 2008, McShea et al. 2008, 

Myers et al. 2008). 

Studies of wildlife-vehicle collisions generally fall into two categories: 1) those investigating a 

broad area for potential hotspots of animal-vehicle collisions, and 2) those investigating already 

identified hotspots. Results from both types of studies are provided here to provide context on 

collision rates (Table 13). Four studies have collected systematic data on vehicle/wildlife 

collisions in Arizona. Dodd et al. (2007) studied 17 miles (27 km) of State Route 260 in central 

Arizona and documented a mean elk/vehicle collision rate of 1.6 collisions per mile per year. 

71 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 13. Summary of Wildlife-vehicle Collision Rates in the U.S. 

Author Focal 

species State 

Type of 

Study/type of 

manipulation 

Wildlife fatalities1 

General With 

manipulation 

Without 

manipulation 

Bissonette and 

Kessar 2008 Deer Utah Broad area 0.84 

DVCs/mile/year - -

Craighead et 

al. 2009 

Deer, elk, 

moose 

Montana Hotspot/ 

Wildlife fence - 4.3 

UVC/mile/year 

10.9 

UVC/mile/year 

Dodd et al. 

2007 Elk Arizona Hotspot 

1.6 elk 

collisions/mile/ 

year 

- -

Dodd and 

Gagnon 2010 Elk Arizona Hotspot/ 

Wildlife fence - 2.86 elk 

collisions/km 

0.68 elk 

collisions/km 

Gleason and 

Jenks 1993 Deer South 

Dakota Hotspot 6.3 deer 

fatalities/km - -

Grovenburg et 

al. 2008 Deer South 

Dakota Broad area 

1.32 deer 

fatalities/mile/ 

year 

- -

Gunther et al. 

1998 

Bison, 

moose, 

antelope, 

whitetailed deer, 

black bear 

Wyoming Broad area 

0.44 large 

mammal road 

fatalities/mile/ye 

ar 

- -

Kline and 

Swann 1998 

All 

vertebrates Arizona Broad area 

11.5/mile/year 

and 

6.0/mile/year 

(depending on 

location) 

- -

Myers et al. 

2008 Deer Washington Broad area 

0.19 

collisions/mile/ 

year (eastern), 

0.63 

collisions/mile/ 

year (western) 

- -

Wakeling et al. 

2008 

(reviewed in 

Gagnon et al. 

2009) 

Bighorn 

sheep Arizona Hotspot 2.1 sheep per 

mile per year - -

1. Collision rates are presented as they were provided in the reference. DVC = deer vehicle collisions, UVC = ungulate 

vehicle collisions. 

After State Route 260 was re-constructed and fencing implemented to funnel elk toward 

underpasses, the mean elk/vehicle collision rate decreased to 0.68 collisions per km per year 

(1.1 collisions per mile per year; Dodd and Gagnon 2010). Kline and Swann (1998) conducted 

systematic surveys of carcasses along roads at the Saguaro National Park and found 11.5 

carcasses per mile in the Tucson Mountain District and 6.0 carcasses per mile in the Rincon 

Mountain District, 36 percent of which were mammals. Wakeling et al. (2008, reviewed in 

Gagnon et al. 2009) documented 17 collisions per year for bighorn sheep along an eight-mile 

section of highway along U.S. Highway 191 in east central Arizona (2.1 sheep/vehicle collisions 

72 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

per mile per year). Additional data associated with the U.S. Highway 93 highway alignment 

estimated bighorn sheep fatalities of 10 sheep per year on Highway 93 prior to the highway 

alignment (Cunningham and Hanna 1992 as cited in AZGFD 2011a). In 2011, 4 bighorn sheep 

fatalities were documented (AZGFD 2011a). 

Arizona Department of Transportation (ADOT) tracks motor vehicle crash facts (ADOT 2011). 

These reports show that over the period from 1997 to 2010, approximately 1 percent of all 

vehicle crashes in the state occurred as a result of collisions with animals (Table 14). 

Table 14. Statewide Crashes in Arizona (ADOT 2011) 

Year 

Total 

Number of 

Crashes 

Total Number of 

Crashes Due to 

Animal Collision 

Collisions with 

Animals - Urban 

Collisions 

with Animals ­

Rural 

Proportion of all 

Collisions Due to 

Animals 

2010 106177 1561 182 1379 0.01 

2009 106767 1787 206 1581 0.02 

2008 119588 1481 187 1294 0.01 

2007 140371 1677 187 1490 0.01 

2006 140197 1398 204 1194 0.01 

2005 139265 1163 175 988 0.01 

2004 138547 1489 209 1280 0.01 

2003 130895 1414 154 1260 0.01 

2002 134228 1791 223 1568 0.01 

2001 131573 1638 177 1461 0.01 

2000 131368 1671 152 1519 0.01 

1999 125764 1480 155 1325 0.01 

1998 120293 1136 114 1022 0.01 

1997 114174 1285 158 1127 0.01 

8.2 Overview of Carcass Search/Removal as Compensatory Mitigation 

BP Wind Energy will implement a roadside carcass search/removal program in which roads in 

target areas will be surveyed at regular intervals for eagles and carcasses of mammals, and any 

large carcasses will be removed from the roads and translocated to the nearest reasonably safe 

and accessible site away from the road. This translocation will keep the carcasses available to 

eagles while reducing the risk of vehicle collisions. Carcass search/removal and concurrent 

eagle occurrence surveys will be conducted from September 15 through April 15 (7-month 

period) when the primary food sources for golden eagles are more limited, and the eagles tend 

to feed more frequently on carrion (e.g., roadkill; see Section 8.1.2; Kochert et al. 2002), placing 

them at greater risk of collision than at other times of the year. This timing will also capture the 

ungulate breeding (rut) period, during which ungulates are more active and more susceptible to 

vehicle collisions than at other times of year (Dussault et al. 2006, Bissonette et al. 2008, 

Grovenburg et al. 2008, McShea et al. 2008, Myers et al. 2008). Surveys will initially be 

conducted at 3- to 4-day intervals, which AZGFD believes to be optimal timing in Arizona 

(AZGFD 2012b). 

73 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

8.3 Implementing Mechanisms 

BP Wind Energy is proposing a contribution of funds to the AZGFD to expand their current 

carcass removal program. In the current program, the state’s objective is to reduce the collision 

risk to humans and wildlife by removing incidentally found carcasses from the roadside either by 

completely removing carcasses from an area or by moving carcasses several hundred feet off 

the road (D. Kephart, AZGFD, 2012, pers. comm.). The implementing mechanism will be a 

contract with the AZGFD Research Branch that can be implemented once a scope of work and 

cost are agreed upon. An alternative mechanism that the USFWS has indicated is also feasible 

may involve hiring consultants independently. BP Wind Energy’s current preference is to use 

the AZGFD contracting mechanism. 

8.4 Bottom-up and Top-down Approaches for Mitigation 

BP Wind Energy and AZGFD concurrently developed approaches for a carcass search/removal 

program, both of which were focused on identifying, quantifying, and reducing uncertainty 

associated with carcass search/removal as a mitigation strategy. Both approaches also 

represent independent lines of evidence for deriving the same outcome, in other words, the total 

number of road miles of carcass search/removal that would be needed to provide compensatory 

mitigation for the take of one eagle. BP Wind Energy focused on a “bottom-up” parameterization 

that was based on the rates of carcass occurrence and use of those carcasses by eagles 

(hereafter, the “bottom-up approach”). The approach developed by AZGFD focused on a “topdown” parameterization (hereafter the “top-down approach”) to carcass search/removal based 

on statewide estimates of eagle densities, fatality rates, and population size. Although both 

approaches present different strategies and input parameters, they are included here to bracket 

the range in the total number of miles needed to provide compensatory mitigation for the take of 

one eagle. Using both approaches to bracket the total level of effort needed is a way of 

addressing uncertainty while being conservative, which BP Wind Energy understands to be a 

key component of acceptability for testing a new compensatory mitigation model for the 

USFWS. 

The following sections describe the key parameters of both approaches. The nine step bottomup approach is presented in Section 8.5 and the three step top-down approach is presented in 

Section 8.6. In each step, the logical framework is described, input values are identified, 

calculations are executed, underlying assumptions are identified, a level of certainty is 

described, and a testing/adaptive management strategy is provided. Finally, a synthesis of the 

miles of road where carcass search/removal will need to be completed to compensate for the 

take of one eagle is provided and a description of how the adaptive management framework will 

inform assumptions in both approaches (Section 8.7). 

8.5 Bottom-up Approach for Mitigation 

This section presents the nine-step bottom-up method developed by BP Wind Energy and Tetra 

Tech for estimating the number of eagles saved from vehicle collisions as a result of 

implementation of a roadside carcass search/removal program (Table 15). This approach is 

based on estimating the number of roadside carcasses available to eagles and the number and 

proportion of eagles using those carcasses which get struck by vehicles. The subsections below 

74 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

present the input values and logic process, calculations, assumptions, certainty, and 

testing/adaptive management strategies. 

Table 15.	 Summary of Steps Taken to Calculate the Number of Golden Eagles Saved per 

Mile of Road Where Carcasses are Removed 

Step Metric Values Units Certainty 

Step 1 

Location of area 

to be targeted for 

mitigation 

- -

Moderate – based on AZGFD eagle 

nest surveys and Species of Economic 

and Recreational Importance database 

Step 2 

Annual rate of 

carcass 

occurrence 

0.2-0.3 Per mile per 7­

month period 

Moderate - can be substantiated with 

real data, although data may not be 

location specific. 

Step 3 

Carcasses 

available for 

eagles 

20-30 

(calculation) 

Total carcasses 

per 100 miles of 

road per 7-month 

period 

Moderate - can be substantiated with 

real data, although data may not be 

location specific. 

Step 4 

Percent of 

carcasses with 

eagles 

20 Percent Low - no data to substantiate. Based 

on expert opinion. 

Step 5 Number of eagles 

per carcass 

1 Eagles Moderate - experts consistent in their 

opinions. 

Step 6 Number of eagles 

using carcasses 

4-6 

(calculation) 

Eagles using 

carcasses per 

100 miles of road 

per 7-month 

period 

Low to moderate - calculation based 

on other data with low to moderate 

confidence. 

Step 7 

Percent of eagles 

on carcasses 

involved in 

vehicle collisions 

5 Percent Low - no data to substantiate. Based 

on expert opinion. 

Step 8 

Number of eagles 

that would be 

involved in 

vehicle collisions 

0.2-0.3 

Eagles saved per 

100 miles of road 

per 7-month 

period 

Low - calculation based on other low 

certainty data. 

Step 9 

Miles of road to 

be used for 

carcass 

search/removal 

implementation 

333-500 

(calculation) 

Miles of carcass 

search/removal 

during a 7-month 

period to mitigate 

for one eagle 

(i.e., number of 

miles required to 

be searched 

during each 3-4 

day search 

interval) 

Low to moderate –based on certainty 

of previous steps 

8.5.1	 Step 1: Determine Where Mitigation Efforts Should Be Targeted Within 

Arizona 

AZGFD requested that mitigation be within the state of Arizona and within the natal dispersal 

distance of the eagles impacted to ensure the benefits of mitigation accrue to the local 

population of eagles (K. Jacobson, AZGFD, 2012, pers. comm.). Golden eagles that breed in 

northwestern Arizona are non-migratory, and are likely permanent residents; however, 

75	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

individuals that breed north of 55 degrees latitude migrate south and could possibly overwinter 

in Arizona (Kochert et al. 2002). Non-breeding adult and immature golden eagles, however, may 

move over large distances (Kochert et al. 2002), and may be encountered anywhere in Arizona. 

Year-round population densities are approximately 1.2 eagles per 1,000 km2 (1.2 eagles per 

386 mi2 or 0.31 eagles per 100 mi2

) for Arizona (Boeker 1974). Information regarding winter 

densities of eagles in Arizona is not available, but elsewhere in the region winter densities of 

golden eagles in Texas and New Mexico were generally low overall with Texas having fewer 

wintering golden eagles (8 per 1,000 km2 or 2 per 100 mi2

) than New Mexico (62 per 1,000 km2 

or 16 per 100 mi2; Boeker and Bolen 1972). 

The carcass search/removal program will be most successful in areas where eagles and large 

carcasses overlap. To identify mitigation areas used by eagles, BP Wind Energy will evaluate 

the intersection of roadways within areas identified as suitable golden eagle habitat (Figure 11; 

derived from the top-down strategy, Section 8.6.1.1). Only road classes 1-3 in a digitized road 

surface GIS layer obtained from ADOT were incorporated. These classes include all interstate 

freeways, highways, and major arteries throughout the state, including unpaved roads with 

speed limits exceeding 40 mph. A total of 5,440 miles (8,755 km) of potential mitigation 

roadways (i.e., roads in suitable golden eagle habitat) were identified based on golden eagle 

suitable habitat in Arizona (Figure 11). To focus mitigation efforts on areas with increased 

potential for carcass occurrence, we incorporated a spatial layer that showed densities of large 

mammal of Species of Economic and Recreational Importance (SERI) for which quantified 

population densities were available (HDMS 2012). These included bighorn sheep, black bear, 

elk, javelina, mountain lion, mule deer, and pronghorn. The density categories of low, very low, 

and scarce were excluded in order to highlight those areas with elevated (i.e., medium, high, 

very high) large mammal densities. Density categories reflected on the map represent the 

maximum density category of all species present in a given area. Of the roadways identified in 

golden eagle habitat, 2,635 miles (4,242 km) intersected with areas of elevated large-mammal 

population densities. Based on this analysis, BP Wind Energy will target roads in northcentral 

Arizona for carcass search/removal, because this region contains a large amount of golden 

eagle habitat that supports elevated densities of large mammals; red box in Figure 11). 

Assumptions: This step assumes that AZGFD data are representative of areas with breeding 

golden eagles and large mammal populations and that vehicle strikes occur only on class 1-3 

roads. 

Certainty: Certainty in these values is moderate because an extensive survey of golden eagle 

nests was conducted by AZGFD in the last 1-2 years (AZGFD 2011b, SGEMC 2012), and all 

known vehicle strikes of golden eagles in Arizona occurred on class 1-3 roads selected (M. 

Piorkowski, AZGFD, 2012 pers. comm.). 

76 December 2012 
Potential target 

mitigation area 

Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Figure 11.	 Preliminary Roadways Identified for the Implementation of a Carcass 

Search/removal Program Using a Kernel Analysis to Define Golden Eagle 

Habitat and SERI Data on Large Mammal Population Densities (Tribal Lands and 

the Phoenix Metro Area Were Not Reported or Included in Analyses). 

77	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Test/Adaptive Management: To determine whether eagle abundance is sufficient in the target 

area to make it appropriate for carcass search/removal, road surveys with regular stops based 

on the protocol outlined in Eakle et al. (1996) or equivalent methods will be used to estimate 

seasonal eagle occurrence in the target area. This method will entail roadside golden eagle 

surveys from the roads where carcass search/removal is conducted from September to April. 

Eagle occurrence surveys will be conducted by the same personnel performing carcass 

search/removal, and will be concurrent with carcass search/removal surveys. Each survey team 

will consist of 1-2 surveyors who will drive the roads scanning for eagles and road-killed 

carcasses and will also make regular stops to scan for eagles. Technical details of the survey 

protocol will be developed in consultation with USFWS, BLM, Reclamation, and AZGFD. 

Tetra Tech set a minimum threshold value for eagle abundance on the survey route based on 

the ratio (0.75) of the average year-round population density of golden eagles in Arizona to the 

average year-round population density in New Mexico (Boeker and Bolen 1972, Boeker 1974) 

where Eakle et al.’s (1996) study was performed. This ratio (0.75) was used to calculate the 

minimum threshold of abundance based on the relative abundance of eagles detected per km of 

roads surveyed reported by Eakle et al. (1996; 34.9 eagles/1,000 km (56.2 eagle/1,000 miles) in 

fall-winter and 9.7 eagles/1,000 km (15.6 eagles/1,000 miles in spring-summer)) for New 

Mexico. This approach produced a minimum threshold of 26.2 eagles/1000 km (42.2 

eagles/1,000 miles) in fall-winter and 7.3 eagles/1,000 km (11.7 eagles/1,000 miles) for springsummer. A weighted average of these values was then calculated (22.2 eagles/1,000 km or 

35.8 eagles/1,000 miles) and used as the minimum threshold for eagle abundance for the 7­

month period (September 15 through April 15). If the concurrent surveys do not detect eagle 

use in the target area equivalent to this threshold, BP Wind Energy will evaluate alternate 

mitigation locations in Arizona using the most recent golden eagle data. Additional statewide 

golden eagle nest surveys are planned by AZGFD for 2013 and 2014, and these may aid in 

further refinement of the target mitigation area (AZGFD 2012b). See Step 2 for testing/adaptive 

management for carcass occurrence. 

8.5.2 Step 2: Evaluate the Annual Rate of Carcass Occurrence 

Because carcass occurrence rates impact the level of effort, developing an initial data-driven 

value and adaptive management program are critical to the success of this approach. Annual 

carcass occurrence values reported in Arizona for large mammals range from 1.1 carcasses per 

mile per year for elk (0.68/km; Dodd and Gagnon 2010) to 2.1 carcasses per mile per year for 

bighorn sheep (1.2/km; Wakeling et al. 2008, reviewed in Gagnon et al. 2009). Whereas these 

values are derived from areas having perceived wildlife-vehicle collision problems, and may 

therefore be high compared to other portions of the state, they represent the best data available 

for this step. In an effort to be conservative, Tetra Tech weighted these empirical carcass 

occurrence rates by 0.25 to account for the likelihood that typical carcass occurrence rates in 

areas with large mammals will be considerably lower than were found in these surveys. The 

resulting estimate of carcass occurrence rate ranged from 0.3 – 0.5 carcasses per mile of roads 

per year, or 0.2 – 0.3 carcasses per mile of roads per 7-month period. 

Assumptions: This step assumes that the adjusted rates of carcass occurrence are reflective 

of the rates of carcass occurrence throughout the state, and that carcass occurrence is uniform 

throughout the mitigation period. 

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Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Certainty: Certainty is moderate because the estimate is based on actual rate data for portions 

of the state; however, it is unknown how well the scaled data will extrapolate to other areas of 

the state that may have lower or higher rates of carcass occurrence. 

Test/Adaptive Management: Once the carcass search/removal program has begun, the rate of 

carcass occurrence within the target mitigation area can be estimated from the number and 

locations of carcasses encountered. In order to evaluate if the estimated carcass occurrence 

rate is adequate in the target mitigation area, the number of carcasses found per mile will be 

calculated and if this value is less than 0.2 carcasses per mile of roads for the 7-month period 

then BP Wind Energy will evaluate other potential mitigation areas in Arizona. 

8.5.3	 Step 3: Calculate the Number of Carcasses Available for Eagles per 100 

miles of road 

Here, the number of carcasses available annually for eagles per 100 miles of roadway in 

suitable golden eagle habitat is estimated. A 100-mile metric was chosen because it was the 

appropriate order of magnitude for this effort to result in an estimate of eagles saved between 

0.1-1.0. Multiplying 100 miles by the low end of the range of carcasses per mile per 7-month 

period (0.2, from Step 2) yielded an estimate of 20 carcasses per 100 miles per 7-month period 

along roadways in suitable golden eagle habitat. Using the high end of the range of carcasses 

per mile per year (0.3, from Step 2) yielded an estimate of 30 carcasses per 100 miles of road 

per 7-month period. 

Assumptions: This step makes the same assumption as Step 2, and also assumes that the 

scale of the analysis in Sections 8.5.1 and 8.5.2 represents a reasonable scale at which to 

evaluate suitable eagle habitat. It also assumes that roads are equally distributed across 

suitable golden eagle habitat. 

Certainty: Same as Step 2. 

Testing/Adaptive Management: Same as Step 2. 

8.5.4	 Step 4: Calculate the Percentage of Carcasses Used by Golden Eagles 

Because estimates of the percentage of roadkill carcasses that might be used by golden eagles 

are not available in the literature, Tetra Tech interviewed eagle experts David Bittner, Peter 

Bloom, Gregg Doney, Teryl Grubb, Alan Harmata, Thomas Maechtle, and Brian Millsap. These 

experts have collectively studied golden eagles for over 200 years, with an average individual 

experience of greater than 30 years (Table 16). All of the experts interviewed by Tetra Tech 

have spent considerable time monitoring carcasses and live lures set out for eagle capture, or 

monitoring carcasses along roads for eagle attendance. The eagle experts suggested that the 

range of carcasses having associated eagles likely varied from 0-85 percent depending on the 

time of year, location of the carcass, weather conditions, prey availability, and other variables. 

To be conservative, Tetra Tech assumed that 20 percent of the carcasses will attract foraging 

golden eagles. 

Assumptions: Assumed that 20 percent of the carcasses will attract foraging golden eagles 

during some part of any given day. 

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Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 16. Eagle Experts Contacted and Their Associated Expertise, Affiliation, and Years of 

Experience 

Expert Expertise Affiliation Years of Experience 

David Bittner Eagle ecology 

Eagle trapping Wildlife Research Institute 44 

Peter Bloom Eagle trapping 

Eagle ecology Bloom Biological, Inc. 35 

Gregg Doney Eagle trapping Independent raptor researcher 20 

Teryl Grubb 

Eagle ecology 

Eagle use of carcasses 

on roads 

USFS Rocky Mountain 

Research Station 35 

Alan Harmata Eagle ecology 

Eagle trapping Montana State University 35 

Thomas 

Maechtle 

Eagle trapping 

Eagle ecology 

Big Horn Environmental 

Consultants 30 

Brian Millsap Eagle trapping 

Eagle ecology USFWS 34 

Daniel Driscoll Eagle ecology 

Eagle trapping 

American Eagle Research 

Institute 28 

Certainty: Certainty in this value is low because these data have not been collected 

systematically and because there are multiple variables that could change the probability that an 

eagle uses a carcass. 

Testing/Adaptive Management: A subset of translocated carcasses will be monitored using 

cameras to validate BP Wind Energy’s estimate of the percentage of carcasses that are used by 

eagles. If less than 5 percent of the carcasses are visited by eagles over the 7-month period of 

the carcass search/removal program and weather conditions are normal for the area, BP Wind 

Energy will evaluate other potential mitigation areas in Arizona using the most recent golden 

eagle data, or will expand the mileage surveyed if additional mitigation is needed. 

8.5.5 Step 5: Calculate the Number of Eagles Per Carcass 

As with Step 4, Tetra Tech relied on information from eagle experts (Table 16) to provide data 

on the number of eagles per carcass. Answers were based primarily on experience with golden 

eagles, but some experts also included bald eagles in their answers; therefore, this value 

pertains to both species combined. Their answers suggested that 1 eagle per carcass was the 

most common (range 1-4 eagles per carcass); however, they have also seen large numbers of 

eagles in the vicinity of the carcass waiting for an opportunity to feed on the carcass (6-17 

golden eagles). Because of the consistency in the responses, Tetra Tech assumed that a single 

eagle would feed on a carcass at a time. 

Assumption: Assumed that a single eagle would feed on a carcass at a time. 

Certainty: Certainty in this value is moderate because the experts were consistent that the 

most likely number of eagles per carcass was one. 

Testing/Adaptive Management: Carcass search/removal surveys may also provide validation 

of the number of eagles per carcass, and a subset of carcasses will be monitored using 

80 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

cameras. Camera data will be used to determine the average and range of numbers of eagles 

photographed using carcasses. 

8.5.6	 Step 6: Calculate the Number of Eagles Using Carcasses 

To determine the number of eagles using carcasses, Tetra Tech multiplied the estimated 

number of carcasses available in 100 miles of roadway per 7-month period (20-30, Step 3) by 

the proportion of carcasses used by eagles (0.2, Step 4) and the number of eagles per carcass 

(1, Step 5). This yielded a low estimate of 4.0 eagles using carcasses per 100 miles and a high 

estimate of 6.0 eagles using carcasses per 100 miles in a 7-month period. 

Assumptions: Same as Steps 3, 4, and 5. 

Uncertainty: Same as Steps 3, 4, and 5. 

Testing/Adaptive Management: Same as Steps 2, 4, and 5. 

8.5.7	 Step 7: Evaluate the Percentage of Eagles Involved in a Vehicle Collision 

While Feeding on Carcasses 

For this step, Tetra Tech asked the eagle experts (Table 16) what percentage of eagles that are 

feeding on roadside carcasses will likely have a vehicle collision. Responses ranged from “too 

many” to “rarely”. Two experts provided percentages; one was 1-5 percent and the other was < 

20 percent. Based on these values, Tetra Tech used 5 percent. 

Assumptions: Tetra Tech assumes that 5 percent of eagles feeding on roadside carcasses are 

struck by vehicles. The 5 percent rate of vehicle strikes assumed here falls within the range 

found at the population level (4-7 percent, Hunt 2002; Tetra Tech 2011; K. Jacobson, AZGFD 

pers. comm.). Tetra Tech interprets this information as supportive of the assumption. 

Certainty: Tetra Tech’s certainty for this value is low because it likely depends on a range of 

values, and available data are anecdotal and have not been systematically collected. 

Testing/Adaptive Management: This step can be evaluated if the number of eagles involved in 

a vehicle collision while exploiting carcasses in Arizona is measured. The number of eagles 

confirmed to have been killed by vehicle collision in the state during the 7-month period will 

serve as a minimum estimate of the total number killed, because some carcasses may be 

collected illegally and some carcasses may be overlooked (e.g., an eagle struck by a vehicle 

may move away from the roadway before dying). Assuming that AZGFD is able to obtain 

reasonably accurate records of eagle-vehicle collisions occurring during the carcass 

search/removal program, BP Wind Energy will be able to use this information and most recent 

estimate of statewide eagle fatalities from AZGFD to update the estimated proportion of eagle 

fatalities that is due to vehicle collisions. 

8.5.8	 Step 8: Calculate the Number of Vehicle-Eagle Collisions per Year in the 

Absence of Carcass Search/Removal 

For this step Tetra Tech multiplied the number of eagles using available carcasses per 100 

miles of road in a 7-month period (4-6, Step 6) by the percentage of eagles involved in a vehicle 

collision while feeding on carcasses (5 percent, Step 7). This equation provides the number of 

81	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

eagles that would be saved by implementing the carcass search/removal program for a 7-month 

period along 100 miles of road within the target mitigation area. This step yielded an estimate of 

0.2 – 0.3 vehicle collisions per 100 miles of road per 7-month period.
 

Assumptions: Same as Steps 6 and 7.
 

Certainty: Certainty in this value is low because multiple data points used in this calculation
 

were based on interpreting incidental observations. However, these data are the best available.
 

Testing/Adaptive Management: Same as Steps 6 and 7.
 

8.5.9 Step 9: How Many Miles of Roads Will Have Carcass Search/Removal 

The following equation was used to determine the total number of mitigation miles per eagle. 

The estimated high and low ends of the range are presented here. 

Total Mitigation Effort (high) 

N = Number of eagles that are being mitigated x (100 miles of roads)/ (# eagles 

struck by vehicles per 100 miles of roads per 7-month period) 

N = 1 eagle to be mitigated x 100 miles of roads/0.2 eagle collisions per 100 

miles of roads per 7-month period 

N = 500 miles of mitigation effort over a 7-month period 

Total Mitigation Effort (low) 

N = Number of eagles that are being mitigated x (100 miles of roads)/ (# eagles 

struck by vehicles per 100 miles of roads per 7-month period) 

N = 1 eagle to be mitigated x 100 miles of roads/0.3 eagle collisions per 100 

miles of roads per 7-month period 

N = 333 miles of mitigation effort 

Using these equations, if mitigation is required for one eagle, then carcass search/removal will 

need to occur over 333-500 miles of road for one 7-month period (September-April). 

Assumptions: Same as Steps 1-8 

Certainty: Certainty is low to moderate because the certainty levels of the input values range 

from low to moderate (see Steps 1-8) 

Testing/Adaptive management: Same as Steps 1-8 

8.6 Top-down Approach for Mitigation 

This section presents the top-down approach developed by AZGFD for estimating the number 

of eagles saved from vehicle collisions as a result of implementation of a roadside carcass 

search/removal program. The top-down approach relies on the following three input parameters, 

which are detailed in the subsections below: (1) the eagle fatalities attributed to motor vehicle 

82 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

collisions; (2) the total number of road miles within habitat occupied by golden eagles; (3) the 

number of road miles to be managed. As with the bottom-up approach, the subsections below 

present the input values and calculations, assumptions, certainty, and testing/adaptive 

management strategies. 

8.6.1	 Step 1: Estimate the Number of Golden Eagles Killed by Vehicle Collision 

in Arizona 

The potential effect of vehicle collisions on a given population of golden eagles may be 

estimated by the following equation: 

k = n*m*v 

where k is the expected number of golden eagles killed on roads annually; n is the estimated 

total number of golden eagles annually occurring in Arizona; m is the inverse of survivorship 

(i.e., mortality); and v is the proportion of golden eagle annual mortality attributed to vehicle 

collisions. 

8.6.1.1 Step 1, Part a. Estimate n, the total number of golden eagles in Arizona 

A systematic, late-summer survey of golden eagles was conducted annually during 2006-2011 

by Nielson et al. (2012) in the Southern Rockies-Colorado Plateau BCR (BCR 16), which covers 

western Colorado, eastern Utah, northwestern New Mexico, and the northern one-third of 

Arizona (NABCI 2000). The annual density of golden eagles of all ages in the BCR, calculated 

from data in Nielson et al. (Table 5; 2012), was 0.003-0.009 eagles/km2 (90 percent confidence 

interval). Areas of tribal lands also contain breeding eagles; however, these data are not 

publically available (R. Murphy, USFWS, 2012 pers. comm.). 

Assuming that 1) adults comprise about one-half to two-thirds of the golden eagle population 

(based on a mean of 51.7-69.2 percent of golden eagles classified as adults or adults/subadults 

in annual late summer surveys across most of the western U.S. by Nielson et al. 2012), and 2) 

about one-fourth of adult golden eagles probably are nonbreeding individuals (based on 

simulations describing saturated breeding populations at Moffat’s equilibrium; Table 3 in Millsap 

and Allen 2006), there may be 0.004-0.005 golden eagles/km2 in this habitat. Given this 

collective perspective, an estimate of 0.003-0.009 golden eagles/km2 for BCR 16, based on 

data in Nielson et al. (2012), seems a low approximation of the species’ mean density in 

Arizona. However, this range seems more plausible when considering that the southwestern 

Arizona region supports few breeding golden eagles (Driscoll 2005), and is used below to derive 

a conservative population estimate within golden eagle habitat in Arizona (Figure 11). 

Using records of occupied breeding areas acquired during surveys of golden eagle nests in 

Arizona in 2011 and 2012 (AZGFD 2011b, SGEMC 2012), a kernel analysis was performed to 

exclude areas of very low golden eagle nesting density (i.e., below that in the Mohave Desert 

portion of west central Arizona, noted above; Figure 11). A spatial configuration analysis 

(nearest neighbor) of documented occupied nests suggested uneven distribution of breeding 

areas throughout the state (AZGFD unpublished data). Nests were examined using a kernel 

analysis function with a 40-mile (64-km) buffer to highlight areas likely to be used by golden 

eagles (including breeding, foraging, and flight corridors; hereafter, golden eagle habitat). The 

40-mile buffer distance was selected because it was inclusive of areas with high breeding 

83	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

densities but excluded low density areas (K. Jacobson, AZGFD, 2012 pers. comm.). This 

analysis was further refined to exclude most tribal lands and the Phoenix Metro Area (Figure 

11). This area was also used in Step 2 (Section 8.6.2) and the bottom-up approach (Section 

8.5.1) to estimate the potential road mitigation miles. The resulting area was digitized and 

became the functional unit to derive the state population size. This resulted in 121,868 km2 

(47,053 square miles) of the state (excluding tribal lands) deemed as suitable golden eagle 

habitat for the basis for estimating golden eagle population size (n). Total population was then 

estimated as: 

n = d * a 

where n = total number of golden eagles in a geographic unit of interest, d = estimated density 

(0.003 to 0.009/km2

, from above), and a = total area (km2) in the geographic unit of interest 

(121,868 km2 for the area of Arizona depicted in Figure 11). Thus, 

n = 0.003 to 0.009/km2 * 121,868 km2 = 365 to 1,097 golden eagles 

Use of the higher bound of the estimate (1,097 eagles) based on the upper 90 percent 

confidence internal of the eagle density may be justified to help account for occurrence of nonresident individuals during migration and winter periods. The lower bound seems implausible, 

however, because at least 428 breeding adults were represented by 214 distinctly separate 

breeding areas documented as occupied by breeding pairs during 2011-2012 nest surveys 

(AZGFD 2011b, SGEMC 2012), cross-referenced with a dataset of recently occupied (i.e., 

within the last 10 years) breeding areas obtained from Arizona’s HDMS (2012). In order to 

adjust population size based on the Arizona breeding data, the same assumptions regarding 

adult composition in the population (see Section 8.6.1.1 above) were applied to the 428 

breeding eagles estimated from nest surveys. This resulted in a reasonable, conservative 

estimate of the lower bound of a population estimate of 827 individual golden eagles. Thus, the 

population estimate on which this mitigation program is based is 827-1,097 golden eagles. 

Assumptions: Data from Nielson et al. 2012 combined accurately reflects the range of 

breeding eagles within Arizona. Numbers of golden eagles migrating from other regions and 

overwintering in Arizona do not substantially influence the estimate of population size. 

Certainty: Moderate. Based on multiple data sources that provide similar data ranges. 

Test/Adaptive Management: Several independent efforts to quantify population size of golden 

eagles in Arizona are ongoing or anticipated in 2013-2014 and can be used to update the 

estimate of population size. The studies include completion by the end of the 2013 breeding 

season of a statewide aerial nest survey of accessible and suitable habitat within non-tribal land 

(includes Department of Defense lands) in each of Arizona’s three main BCRs; a minimum of 

two years (2013-2014) of aerial nest surveys in concert with follow-up ground surveys to 

document occupancy of nests statewide; and regular monitoring of productivity of a 

representative sample of breeding areas within each of Arizona’s main BCRs (McCarty and 

Jacobson 2011). 

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Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

8.6.1.2	 Step 1, Part b. Estimate m, the inverse of survivorship (i.e., mortality) 

Two relatively unbiased estimates of golden eagle survival exist. First, annual survival rates for 

all age classes estimated from 2006-2011 golden eagle survey data in the western U.S. 

(Nielson et al. 2012) averaged 0.90 (n = 5, range 0.70 – 1.0). The second source is Hunt’s 

(2002) radio-telemetry study of the species from the Altamont Pass Wind Farm in California. He 

reported estimates of 0.84 (SE = 0.04), 0.79 (0.02), and 0.91 (0.02) for juveniles, subadults, and 

adults, but acknowledged that juvenile and subadult survival rates were probably higher and 

lower, respectively, than in most populations. Survival rates of other species of Aquila eagles lie 

within the middle of the 0.80–0.90 range (e.g., 0.84 for A. heliaca; Rudnick et al. 2005). 

Assumptions: Survival rates calculated by USFWS biologists B. Millsap and R. Murphy for the 

four BCRs (9, 10, 16, 17) sampled by late-summer aerial transect surveys are a good 

approximation of survival rates of golden eagles in Arizona. Data from Altamont Pass, California 

collected by Hunt (2002) are unbiased estimates of background vital rates and were not 

significantly biased by transmitter failures or the high rate of mortality due to collisions with wind 

turbines and electrocution (i.e., vehicle strikes are not compensatory with other sources of 

mortality). Survival rates of Aquila species are similar throughout the genus. 

Certainty: Moderate, because although the estimates from Hunt 2002 represent unbiased data 

for the area, the location of the study in an area with high golden eagle fatalities due to wind 

farm collisions may bias the data when applied to the state of Arizona. Similarly, data from 

Nielson et al. 2012 results assume late summer sampling provides an unbiased estimation of 

eagles breeding in the desert and that estimates from BCR 16 apply to the entire state of 

Arizona. 

Test/Adaptive Management: Survival of golden eagles in the western U.S. is being 

documented currently via satellite telemetry and results should be available within 2-3 years to 

improve upon this important demographic metric (R. Murphy, USFWS, 2012 pers. comm.). 

8.6.1.3	 Step 1, Part c. Estimate v, the proportion of golden eagle annual mortality 

attributed to vehicle collisions 

Vehicle collisions represented 5 (21 percent) of 24 golden eagle fatalities reported in Arizona 

during 2000-2011, but this form of mortality is more likely to be discovered and reported than 

other sources. However, in the past year AZGFD documented six vehicle-collision fatalities of 

golden eagles in Arizona (K. Jacobson, pers. comm.). If annual mortality of the golden eagle in 

Arizona is 0.1-0.2 (inverse of survival rate, above) and the population size is at least 827 

individuals (above), six fatalities attributed to vehicle collisions represent 4-7 percent of the 

year’s mortality. Using radio telemetry, Hunt (2002) attributed four (4 percent) of 100 fatalities of 

golden eagles at the Altamont Wind Resource Area in California to vehicle collisions. This level 

may be lower than that in other areas because 1) some transmitter failures that occurred during 

the study may have been associated with vehicle collision, and 2) substantial mortality due to 

collision with wind turbines in the area may have been compensatory with some vehicle-collision 

mortality. Based on a comprehensive review of records in the U.S. public domain, 5 percent 

(119) of records of human-caused fatalities of golden eagles were due to vehicle collisions 

(Tetra Tech 2011). Stemming from close corroboration among the last three sources of 

information, the percentage of golden eagle fatalities in Arizona attributed to collision with 

vehicles likely is within or slightly above this 4-7 percent range and is less likely to be near the 

85	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

21 percent level suggested by incidental reports from the state. Based on a synthesis of these 

collective sources, USFWS believes a range of 5-10 percent is a reasonable approximation of 

fatality rate (R. Murphy, USFWS, 2012 pers. comm.). 

Assumptions: 1) data from Altamont Pass, California collected by Hunt (2002) are unbiased 

estimates of background vital rates and were not significantly biased by possible transmitter 

failures or the high rate of mortality due to collisions with wind turbines and electrocution (i.e., 

vehicle strikes are not compensatory with other sources of mortality); 2) incidental discoveries of 

vehicle-caused fatalities are reasonably representative of the incidence of this form of mortality. 

Certainty: Low to moderate, because although the estimates from Hunt 2002 represent 

unbiased data for the area, the location of the study in area with high golden eagle fatalities due 

to wind farm collisions may bias the data when applied to the state of Arizona. Other records 

used to develop the estimate were based on incidentally collected information, and may 

therefore be biased. 

Test/Adaptive Management: The proportion of golden eagle annual mortality attributed to 

vehicle collisions can be evaluated during the carcass search/removal program using the 

observed carcass use by eagles, availability of carcasses, and exposure of eagles to vehicle 

collisions. Additionally, results of telemetry work being executed by USFWS in New Mexico and 

elsewhere may provide insights relevant to golden eagle mortality rates in Arizona. 

8.6.1.4	 Step 1, Part d. Estimate k, expected number of golden eagles killed on roads 

annually 

The number of golden eagles killed annually due to vehicle collisions in Arizona (k) is calculated 

from the product of the three parameters n, m, and v, calculated in Steps 1 part a, b, and c, 

respectively. Values used were recommended by USFWS (R. Murphy, pers. comm.). Both 

values of the vehicle-collision mortality rate (v = 0.05 and 0.10) were used to provide a range of 

values. 

When v = 0.05, then k = 1097*0.20*0.05 = 11 golden eagles killed on roads annually in Arizona 

When v = 0.10, then k = 1097*0.20*0.10 = 22 golden eagles killed on roads annually in Arizona 

Assumptions: Same as Steps 1a-1c. 

Certainty: Low to moderate based on information in Steps 1a-1c. 

Test/Adaptive Management: Same as Steps 1a-1c. 

8.6.2	 Step 2: Estimate the Total Mileage of Roads within Habitat Suitable for 

Golden Eagles 

Within the area of golden eagle habitat identified in Step 1 (Figure 11) GIS tools were used to 

calculate the mileage of roads for potential mitigation (see Section 8.6.1.1). The GIS analysis 

identified 5,440 miles (8,755 km) of roadways within golden eagle habitat as potential mitigation 

segments (Figure 11). 

Assumptions: 1) golden eagle habitat is correctly defined, 2) golden eagle fatalities attributed 

to vehicle collisions in Arizona occur only on class 1-3 roads; 3) golden eagle fatalities attributed 

86	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

to vehicle collisions in Arizona are randomly distributed throughout areas with habitat suitable 

for the species; 4) carcasses that attract eagles to feed along roadways are distributed 

randomly throughout areas with suitable habitat for golden eagles. 

Certainty: Moderate. Much of the suitable golden eagle habitat within the state of Arizona has 

been surveyed for golden eagle breeding areas in the past 2-3 years; however, there remain 

large areas of suitable habitat that have not been surveyed in recent years (AZGFD 2011b, 

SGEMC 2012). Data on wildlife-vehicle collisions suggest that primary paved roads have higher 

rates of collisions (see Section 9.1.2). All known vehicle strikes of golden eagles in Arizona 

occurred on class 1-3 roads (M. Piorkowski, AZGFD, 2012 pers. comm.). 

Test/Adaptive Management: Ongoing monitoring of golden eagle breeding areas, in addition 

to other research on golden eagles in Arizona, will improve upon the definition of suitable golden 

eagle habitat. Statewide efforts to document golden eagle vehicle-collision fatalities will help 

refine the assumption about the distribution of golden fatalities. Monitoring of roads during the 

carcass search/removal program will provide information on whether carcass occurrence is 

distributed randomly or is concentrated in specific areas. 

8.6.3	 Step 3: Calculate the Number of Road Miles for Carcass Search/Removal 

to Offset the Loss of One Golden Eagle. 

The number of miles over which the carcass search/removal program is implemented to prevent 

vehicle-collision fatality of one golden eagle is calculated by dividing the number of miles of 

roadway within the golden eagle habitat (Step 2) by the annual vehicle collision mortality 

estimate derived in Step 1. 

Step 1 = 11-22 golden eagle fatalities per year 

Step 2 = 5,440 miles 

Number of road miles to mitigate for one golden eagle fatality = 5,440 miles/11 to 22 golden 

eagle fatalities per year = 247 to 495 miles (398 to 797 km). 

Based on the above estimates and calculations, carcass search/removal would need to be 

conducted along 247 to 495 miles (398 to 797 km) to reduce vehicle collision fatalities of golden 

eagles by one individual. 

Assumptions: Same as in Steps 1 and 2 above. 

Certainty: Moderate, based on certainty of estimates used in Steps 1 and 2 above. 

Test/Adaptive Management: same as Steps 1 and 2 above. 

8.7 Comparison of the Bottom-Up and Top-Down Approaches 

The bottom-up and top-down mitigation approaches obtain an estimate of miles required to 

mitigation for one eagle from either the local level (bottom-up) or the population level (topdown). These two approaches overlap in few input variables (Table 17); therefore, they 

represent relatively independent approaches to developing this mitigation strategy. Despite their 

differences, both the bottom-up and top-down approaches resulted in similar ranges of 

87	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 17. Comparison of Inputs and Adaptive Management Between Bottom-up and Topdown approaches 

Input Bottom-up Top-down Adaptive Management 

Estimating number of eagles killed by cars 

Total number of golden eagles in 

Arizona X 

New and updated data including 

locally available data, current 

scientific literature, and carcass 

search/removal results should be 

assessed at regular intervals 

Golden eagle mortality rates X 

New and updated data including 

locally available data, current 

scientific literature, and carcass 

search/removal results should be 

assessed at regular intervals 

Probability of mortality due to car 

strikes X X 

Monitoring of the mitigation area, in 

addition to incidental eagle-vehicle 

collision records, will evaluate the 

estimated probability of eagle-vehicle 

collisions 

Estimating number of miles to be surveyed 

Total roads X Not subject to adaptive management 

Total number of golden eagles in 

Arizona X 

New and updated data including 

locally available data, current 

scientific literature, and carcass 

search/removal results should be 

assessed at regular intervals 

Annual rate of carcass occurrence X 

To be explicitly tested in adaptive 

management by calculating actual 

number of carcasses found 

Total carcasses available for eagles X 

To be explicitly tested in adaptive 

management by calculating actual 

number of carcasses found 

Percent of carcasses with eagles X 

To be explicitly tested in adaptive 

management by using game 

cameras 

Number of eagles per carcasses X 

To be explicitly tested in adaptive 

management by using game 

cameras 

Number of carcasses with eagles X Calculation based on above 

variables 

Percent of eagles on carcasses 

involved in vehicle collisions X Calculation based on above 

variables 

Number of eagles that would be 

involved in vehicle collisions X X 

Evaluated with monitoring results 

and incidental eagle-vehicle collision 

records 

mitigation miles. The bottom-up approach resulted in an estimated range of 333 to 500 miles 

(536 to 805 km) of mitigation per eagle, whereas the top-down mitigation resulted in an 

estimated range of 247 to 495 miles (398 to 797 km) of mitigation per eagle. To be 

conservative, BP Wind Energy will use the highest value and so will execute 500 miles (805 km) 

of mitigation over a 7-month mitigation period. 

88 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Although few of the input variables for the bottom-up and top-down approaches overlap, 

adaptive management and effectiveness monitoring for both approaches can help inform the 

other. Both approaches use the information collected on eagle use of carcasses either in the 

calculation of miles required (bottom-up) or to confirm that eagles are using carcasses in the 

mitigation area (top-down). Similarly, the bottom-up approach does not explicitly rely on 

population size or demographics, but these data can be used to inform the most advantageous 

location for mitigation. 

8.8 Implementation of the Roadside Carcass Search/Removal Program 

BP Wind Energy will execute a carcass search/removal program as a compensatory mitigation 

measure. BP Wind Energy recognizes that there is uncertainty associated with take and 

compensatory mitigation which can be adaptively managed. After initiation of commercial 

operation of the Project, BP Wind Energy will execute one 7-month period (September – April) 

of roadside carcass search/removal that results in the equivalent of one eagle saved during that 

period (Figure 12). If the adaptive management and testing outlined above indicates that the 

roadside carcass search/removal program has successfully mitigated for one eagle, BP Wind 

Energy will stop the mitigation unless an additional eagle fatality occurs. If an eagle fatality 

occurs, BP Wind Energy will resume the carcass search/removal program or will implement an 

equivalent alternative (e.g., power pole retrofitting; Figure 12) in order to stay one eagle 

equivalent ahead of actual fatalities. BP Wind Energy will evaluate the overall effectiveness of 

the carcass search/removal program by reviewing data collected as outlined in the test/adaptive 

management in Section 8.5 in consultation with USFWS, BLM, Reclamation, and AZGFD. 

For any eagle fatality that occurs, BP Wind Energy will evaluate the fatality in the context of 

environmental conditions at the approximate time when the fatality occurred (e.g., unusual 

weather conditions, management activity within the Project area) and the location of the fatality 

and will actively manage any elements under BP Wind Energy’s direct control (e.g., localized 

carcasses). If this review identifies a problem turbine with multiple fatalities, BP Wind Energy will 

consult with BLM, Reclamation, USFWS, and AZGFD. BP Wind Energy used the best available 

science to estimate golden eagle take associated with the Project; however, the models created 

by the USFWS are currently untested. This could result in take being greater than outlined in 

this ECP-BCS. If take were above the levels discussed here, BP Wind Energy would re-consult 

with USFWS, BLM, Reclamation, and AZGFD. 

89 December 2012 
Project in Operation 

Mitigate for 1 golden eagle fatality by conducting carcass search/removal 

equivalent to 1 golden eagle during the first year of operations. 

Golden eagle fatality? 

No further mitigation. Above 5-year 

permitted take level? 

Re-initiate 

discussions with 

agencies regarding 

take permit. 

Mitigate for golden eagle fatality by either 

initiating another year of carcass 

search/removal or expanding the number of 

miles managed in a single year or 

implement other mitigation efforts. Evaluate 

fatality to determine whether it is unique 

(e.g., unusual weather conditions) or 

indicates a systematic problem. 

No further mitigation. 

No Yes 

Yes No 

Golden eagle fatality? 

No 

Yes 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 12.	 Adaptive Management of Golden Eagle Fatalities at the Mohave County Wind 

Farm 

90	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

BP Wind Energy may choose or need to adaptively manage the carcass search/removal 

program. If the carcass search/removal program appears to be providing adequate mitigation 

but new data suggest that an alternative compensatory mitigation option (e.g., new costeffective technology, availability of pooled mitigation fund) can provide a more cost-effective 

benefit to golden eagles, BP Wind Energy may choose an alternative mitigation approach in 

consultation with the agencies. In contrast, if early tests of the carcass search/removal program 

do not appear to be providing adequate mitigation based on the criteria described In Section 8.5 

during the initial stage of the 7-month effort, BP Wind Energy will work with the USFWS, 

AZGFD, BLM, and Reclamation to 1) modify the carcass search/removal program or 2) conduct 

an alternative mitigation strategy which may include power pole retrofits or 3) implement other 

compensatory mitigation options. If early evaluation of the current carcass search/removal 

program is deemed unsuccessful based on criteria outlined in Section 8.5 and at least half of 

the mileage has been completed, it is BP Wind Energy’s understanding that they will be given a 

credit for a minimum of half an eagle fatality for testing of the carcass search/removal program 

because given the best available information to date the USFWS concurs that this effort should 

provide protection to golden eagles and provide additional information to inform USFWS about 

the success of non-power pole mitigation options. Adaptive management with respect to the 

carcass search/removal program is addressed above in Section 8.7. 

8.9 Operational Mitigation and Adaptive Management for Eagles 

BP Wind Energy has committed to several eagle-specific avoidance and minimization measures 

relative to the Squaw Peak breeding area that was occupied in 2012. The Squaw Peak breeding 

area, in the northwestern corner of the Project footprint (Alternative A), includes a north-south 

ridgeline characterized by a break in topography north of Squaw Peak at the southern end of 

the ridgeline. Collectively the two features comprise the most distinct topographical rise within 

the Project area and contain the majority of golden eagle observations on the Project (Figures 2 

and 3). Sixteen eagle nest structures, classified as a single breeding area, are scattered along 

the western face of an approximately 1-mile portion of the ridgeline; a nest in the center of this 

cluster was active in 2012. 

During the first five years of operation, which coincide with the term of the incidental take permit, 

BP Wind Energy will create a curtailment zone where turbines will be curtailed during the 

breeding season when the Squaw Peak breeding area is occupied (see Section 8.9.1, Adaptive 

Management). The boundary of the curtailment buffer was collectedly derived by the USFWS, 

BLM, Reclamation, Western, AZGFD, and NPS during an in-person meeting on October 2, 2012 

at the USFWS Phoenix office (Table 1). The initial curtailment zone was developed by the 

USFWS’s Eagle Programmatic Permit Implementation Team (EPPIT; R. Murphy, USFWS, 2012 

pers. comm.) following the general approach described in the Draft ECP Guidance for 

categorizing the level of risk where one-half of the mean nearest neighbor distance is 

considered the defended portion of each breeding area and thought to encompass the greatest 

activity by breeding eagles and their young (USFWS 2011a). Based on aerial surveys in late 

winter and spring 2012, 16 possible breeding areas were identified on and within 10 miles (16 

km) of the Project boundary (Section 2.3.3). At least eight of these were classified as occupied, 

based on observations of adults incubating eggs, of nestlings or fledglings, or of adults near 

nests plus sign of recent activity at nests. EPPIT considered five other breeding areas as 

possibly occupied, based on signs of recent nest construction or refurbishment plus fresh 

91 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

whitewash at or near nests. Three other potential breeding areas were considered unlikely to be 

occupied; however, because each was represented only by a single nest structure that lacked 

recent construction activity. Because the USFWS considers the Project an “on-ramp” project, 

initiated several years before the January 2011 Draft ECP Guidance, the criterion of 

simultaneously occupied territories was generally used during review of the Project by the 

EPITT (R. Murphy, U.S. Fish and Wildlife Service, 2012 pers. comm.). Using the eight breeding 

areas verified as occupied and five others considered likely to be occupied, USFWS measured 

the distance from the center of each nest cluster to that of the nearest nest cluster. One-half of 

the mean inter-nest distance was 2.5 miles (4.0 km). 

The initial curtailment zone was a 2.5 mile (4.0 km) radius circle centered on the active Squaw 

Peak nest. However, review by the USFWS EPPIT team and discussions with the resource 

agencies at the October 2012 meeting described above indicated that the documented eagle 

activity in conjunction with the topography and wind direction was suggestive that risk was not 

uniformly distributed within the 2.5-mile radius circle. Rather, risk was predicted to be higher to 

the west and the south and lower to the east of the ridgeline. The resource agencies agreed, 

based on best professional judgment, that the optimal curtailment zone would be reduced by 

about 1 mile (0.8 km) on its east side and extended about 0.5 to 1 mile (0.8 to 1.6 km) on its 

south and southwest sides (Figure 1). 

8.9.1 Adaptive Management of Curtailment Program 

BP Wind Energy developed a curtailment program focused on the breeding activity at the 

Squaw peak nest because telemetry studies of golden eagles have shown that the intensity of 

eagle use is highest surrounding an active nest (Watson et al. 2012; R. Murphy, USFWS, 

unpublished telemetry data). The scope of the curtailment program will focus on the first five 

years of operation as that is the period over which USFWS currently states they can authorize 

an eagle take permit (USFWS 2011a). Section 8.9.1.5 provides additional details on the 

adaptive management of curtailment program within that 5-year period. Although the curtailment 

program was not designed to address non-breeding or wintering eagles, if these types of 

individuals use the area, they will be documented during eagle use surveys (Section 8.9.1.2). 

BP Wind Energy will adaptively manage the timing of the curtailment program using occupancy 

surveys, eagle use surveys, and telemetry as a basis for determining when curtailment should 

begin and end. Occupancy surveys of the Squaw Peak breeding area will serve to determine 

when curtailment needs to be initiated in any given breeding season. Eagle use surveys, 

coupled with telemetry, will serve to determine when curtailment can be concluded in any given 

breeding season after being triggered. Finally, the spatial extent of curtailment within the 

existing curtailment zone will be based on eagle use survey results. As detailed in Section 

8.9.1.4, curtailment will be triggered if occupancy surveys determine that the Squaw Peak 

breeding area is occupied. Curtailment of turbines within the curtailment zone will occur from 

11:00 to 16:00 in December 1 – March 15, and from 4 hours after sunrise to 2 hours before 

sunset March 16 – August 31, or 2 months after the date fledgling eagles leave the nest based 

on golden eagle activity patterns (R. Murphy, USFWS, unpublished data). At least three years of 

eagle use data will be collected prior to considering any relaxation of the spatial extent or 

proposed timing of curtailment within the existing curtailment zone. 

92 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

8.9.1.1 Occupancy Surveys 

Starting in December when courtship and nest building begins (Driscoll 2010), monthly surveys 

will be performed to assess the occupancy of the Squaw Peak breeding area. Occupancy 

surveys will include a combination of ground-based and aerial surveys. It is expected that three 

ground vantage points should provide adequate visual coverage of the 16 known nests in the 

Squaw Peak breeding area. Ground-based surveys will occur for 4 hours per survey. A single 

aerial survey will also be conducted each breeding season in at least the first three years of 

operation between mid-March and April to capture the most likely period when egg laying or 

incubation could occur (Driscoll 2010). Occupancy of breeding areas and nests will be defined 

according to the Arizona Golden Eagle Survey and Monitoring Protocol (SGEMC 2011). 

Occupied Breeding Area: An occupied Breeding Area must have a nest where at least one of 

the following activity patterns is observed: 

a.	 A recently repaired nest with fresh sticks, or fresh boughs on top, and/or droppings 

and/or molted feathers on its rim or underneath. 

b.	 One adult and one bird in immature plumage at or near a nest, if mating behavior was 

observed (display flight, nest repair, copulation). 

c.	 Two adults present on or near the nest. 

d.	 One adult sitting low in the nest, presumably incubating. 

e.	 Eggs seen in the nest. 

f.	 Young seen in the nest. 

Unoccupied Breeding Area: A nest or group of alternate nests at which none of the activity 

patterns diagnostic of an occupied Breeding Area were observed in a given breeding season. 

Active Nest: A nest in which eggs have been laid. 

The breeding area will be considered occupied if any of signs (b) through (f) of occupancy listed 

above are observed. If only sign (a) is observed, a follow-up survey will be conducted within 2 

weeks to verify occupancy status. The breeding area will be considered unoccupied if signs (b) 

through (f) above are not detected after a minimum of four consecutive monthly surveys have 

been conducted (adapted from Driscoll 2010). Occupancy surveys will continue until one of the 

following occurs: 

1)	 The breeding area is determined to be unoccupied; 

2)	 A nest is determined to be active, upon which eagle use surveys will begin (see Section 

8.9.1.2); or 

3)	 The breeding area is occupied but there is no active nest by the end of April. 

8.9.1.2 Eagle Use Surveys 

The objective of the eagle use surveys is to quantify seasonal distribution and intensity of eagle 

use of the curtailment zone, regardless of eagle age, residency, or breeding status. A utilization 

distribution (possibly including data obtained via telemetry) will form the decision-making basis 

93	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

for adaptive management within the existing curtailment zone during the first five years of 

operation. Our null hypothesis is that there is little to no eagle activity in the Squaw Peak area 

when the associated breeding area is unoccupied. We will test this hypothesis by comparing 

results from occupancy surveys and eagle use surveys. Eagle use surveys will occur at up to 

three survey locations that provide good views of the active nest and the turbines within the 

curtailment zone. Surveys will be 8-hour long observations at each point. 

Eagle use surveys will be performed regularly during the first three years of operation. In the 

first two years, surveys will be performed every other week year-round. In the third year, if 

eagles were seen during the non-breeding season, surveys will be performed a minimum of 

every other week during the breeding season (December to fledging in July or August) and a 

minimum of once per month during the rest of the year. If eagles were not seen or were seen 

minimally during the non-breeding season, surveys will be performed every other week during 

the breeding season and effort may be reduced during the non-breeding season. Survey efforts 

may be reduced during the breeding season if efforts to capture both members of the breeding 

pair at Squaw Peak are successful (i.e., transmitters are attached and shown to be fully 

operational). In this event, BP Wind Energy will pay for data transfer services for the 

manufacturer-guaranteed life of the transmitters. These data will be provided to the USFWS for 

additional analysis and research. 

8.9.1.3 Telemetry Monitoring 

A state and federally permitted biologist may attempt to capture adult golden eagles at the 

Squaw Peak breeding area. If capture attempts are successful, data from telemetered 

individuals will be collected via satellite. Locational data will be used to determine the home 

range kernel estimates by month to document the distribution of use of the Squaw Peak 

breeding area by golden eagles. 

8.9.1.4 Curtailment Implementation 

Curtailment of turbines within the existing curtailment zone will be implemented in order to avoid 

and minimize the risk of collisions to eagles using the Squaw Peak breeding area. Curtailment 

will be triggered in the first five years of operation if occupancy surveys determine that the 

Squaw Peak breeding area is occupied. Curtailment of turbines will occur daily from 1) 11:00 – 

16:00 in December 1 – March 15, and 2) 4 hours after sunrise until 2 hours before sunset from 

March 16 – September 30. This timing corresponds to the approximate peak period of flight 

activity of golden eagles in northeastern Arizona and northwestern New Mexico, as determined 

by satellite telemetry (R. Murphy, USFWS, unpublished telemetry data), but extends during midwinter to account for the peak of courtship and territorial display activity by breeding adults. 

Curtailment of turbines within the curtailment zone in any given breeding season will continue 

until one of the following occurs: 

1)	 There is no active nest by the end of April (Driscoll 2010). The assumption is that adult 

birds will gradually disperse away from a nest when it is no longer active; this 

assumption will be evaluated by the ongoing eagle monitoring at the Project. If this 

assumption is not supported by results of the eagle occupancy surveys, and these 

surveys instead indicate that breeding eagles remain near the nest year-round, 

94	 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

curtailment will be conducted from 11:00 – 16:00 in October 1 – March 15, and from 4 

hours after sunrise to 2 hours before sunset from March 16 – September 30; 

2)	 The active nest is determined to have failed as indicated by two, 8-hour eagle use 

surveys without any signs of activity (i.e., adults perched at the nest site, adult in the 

nest, eggs in the nest, young in the nest); or 

3)	 It is two months post-fledgling or less if fledglings have left the curtailment zone. Two 

months was selected because in a recent study by USFWS biologists, 33 PTT-marked 

juvenile golden eagles were within 3 km of their nest 90 percent of the time for at least 2 

months (R. Murphy, USFWS, 2012 pers. comm.). 

8.9.1.5 Adaptive Management 

Data from the surveys and telemetry monitoring will be reviewed by BP Wind Energy, USFWS, 

BLM, Reclamation, and AZGFD annually to assess the evidence of eagle use of the curtailment 

zone. Golden eagle occurrence and breeding effort are related to prey availability and, to a 

lesser extent, weather (e.g., winter severity, precipitation; Millsap 1981, Watson 1997, Steenhof 

et al. 1997, Kochert et al. 2002). Abundance of the black-tailed hare (Lepus californicus), a 

major prey species of golden eagles in western states (Kochert et al. 2002), exhibits marked 

annual variation, such that surveys and studies focused on occurrence and breeding status of 

eagles should encompass multiple years. Thus, at least 3 years of use distribution data using 

telemetry and/or direct observation will be collected on golden eagles in the Squaw Peak area 

before the plan for curtailment of turbines within the existing curtailment zone, as outlined here, 

is revisited. If, after 3 years, eagle use data from telemetry and direct observations indicate 

eagles are not present during non-breeding portions of the year or if they are present, that use 

patterns are much reduced compared to the nesting season, then curtailment may be reduced 

or spatially altered within the existing curtailment zone to reflect eagle use. 

8.10 Mitigation and Adaptive Management for Non-eagle Bird Species 

This section provides an adaptive management framework in which thresholds will trigger 

additional avoidance and minimization measures, as well as compensatory mitigation for noneagle bird species. 

8.10.1 Thresholds 

BP Wind Energy will implement mitigation for non-eagle, migratory bird species if either an 

annual or a turbine-specific threshold is crossed. Thresholds are a transparent means of 

demonstrating accountability and good-faith effort in protecting migratory birds if unanticipated, 

high levels of fatalities occur. BP Wind Energy is committed to avoiding and minimizing losses 

of migratory birds at the Project and incorporates the threshold approach to respond to 

unforeseen fatality events, first and foremost by identifying and correcting problems on-site and, 

as a last resort, through the use of compensatory mitigation. 

BP Wind Energy will employ thresholds for two types of exceedances: systematic and rare. A 

systematic threshold exceedance will be defined as a mean annual rate of fatality over the 

course of any given year that exceeds the annual threshold. A rare threshold exceedance will 

be defined as an event at a single turbine in which Project-related fatalities occurring within a 

single search period are twice the magnitude of the annual threshold. 

95	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Thresholds for non-eagle birds will be based on the mean and variance of fatality rates found at 

wind energy facilities in desert regions in the western U.S. (Table 7b). Fatalities rates from 

regional projects were used to develop thresholds rather than the results from pre-construction 

avian use surveys because studies suggest that pre-construction use surveys are not good 

predictors of rates of fatalities (e.g., Ferrer et al. 2012). In addition, WEST (2011) stated that 

fatalities at similar facilities provide more accurate predictions of rates of fatalities. Furthermore, 

this approach adheres to the Land-based Wind Energy Guidelines which are intended to be 

voluntary and developer-driven according to the USFWS (USFWS 2012). Although fatality 

monitoring studies do not share identical methodologies (e.g., type of carcasses used for 

searcher efficiency and carcass persistence trials, fatality estimate methods), they do represent 

the current state of knowledge, and threshold values will be updated as new data become 

available. The systematic threshold for annual non-eagle bird fatalities will be two SD (1 SD = 

0.83 birds/MW/year) above the western desert region average of 2.05 birds/MW/year. This 

threshold value is 3.71 birds/MW/year (6.65 birds/turbine/year). BP Wind Energy chose two SD 

as a threshold because 97.5 percent of annual fatality estimates in the desert region western 

U.S. would fall below that number (based on Table 7b); therefore, a value above this represents 

an extreme event. The rare threshold value will be defined as twice the systematic threshold, or 

13.30 non-eagle bird fatalities within a single search period at one turbine. 

Thresholds will also be implemented for two subgroups of non-eagle birds that are of particular 

concern: (1) raptor species, and (2) sensitive species (BLM Sensitive species and AZGFD 

SGCN Tier 1A and 1B species, combined). The threshold for the raptor subgroup uses the noneagle fatality threshold scaled by the proportion of pre-construction bird use due to raptors. 

Specifically, detections of non-eagle raptors made up 13.3 percent of all non-eagle bird 

detections; therefore, the systematic threshold for raptor species will be 13.3 percent of the noneagle bird systematic threshold, or 0.49 raptors/MW/year (0.88 raptors/turbine/year). This 

method results in the rare threshold for raptors of 1.76 raptors/turbine/year following the same 

rationale as for non-eagle birds (twice the systematic threshold). 

The threshold for the sensitive species subgroup (i.e., BLM Sensitive species and Tier 1A, 1B 

species) will be the detection of three sensitive species carcasses during a single year of 

monitoring (standardized or incidental). This threshold value was chosen because very few 

detections of sensitive species were made during pre-construction surveys (10 total detections 

excluding eagles from 2007-2011; Appendix A). 

Incidental and WIRS detections will count towards the rare threshold and the sensitive species 

systematic threshold because both of these thresholds use uncorrected counts of carcasses. 

However, because the non-eagle bird systematic threshold requires systematically collected 

data, incidental and WIRS detections will not count toward the non-eagle bird systematic 

threshold. 

8.10.2 Timing of Trigger Evaluation 

BP Wind Energy will proactively review post-construction fatality monitoring data to identify 

threshold exceedances quickly regardless of when in the reporting cycle they occur. For 

example, if a rare threshold is exceeded in a given season, BP Wind Energy will respond before 

the end of that season. This in turn will enable a swift response by BP Wind Energy in terms of 

96 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

assessment of the issue, determination of corrective measures, and communication with 

resource agencies. 

8.10.3 Compensatory Mitigation 

In the event that mitigation thresholds are exceeded and the problem cannot be locally 

corrected, mitigation payments will be made to selected funds that benefit the bird species 

affected. The mitigation payments are voluntary measures provided by BP Wind Energy. These 

may include the research branch within the AZGFD, or non-profit organizations or partnerships, 

or a combination thereof, to be determined in consultation with USFWS, BLM, Reclamation, and 

AZGFD. Most fatalities at wind projects are nocturnal migrants (e.g. Thompson et al. 2011b), 

many species of which only pass through the Project area during migration and use habitats not 

found within the Project area (e.g., ruby-crowned kinglet, yellow-rumped warbler). In order to 

provide a benefit for these species, payments would need to be targeted to regional or national 

organizations (e.g., Partners in Flight, Audubon Society) that perform conservation of habitat at 

breeding and wintering grounds that occur off-site. Funds for mitigation of locally breeding 

species covered by the MBTA would target organizations that perform desert or other local bird 

habitat restoration, or have programs that address reducing bird fatalities (e.g., removing or 

capping mining claim markers which are a source of mortality for small birds; Zuckerman 2012). 

Selection of appropriate funds would be subject to approval by the BLM and Reclamation. 

Mitigation for individual threshold exceedance (rare or systematic) will range from $10,000­

$25,000 per year, depending on the type and recurrence frequency (Table 18). 

Mitigation payments for any given year will be capped at the maximum value for the highest 

threshold trigger exceeded in that year and total Project lifetime payments will be capped at 

$200,000. For example, in Year 1, the cap will be $10,000 for either a rare or systematic 

threshold exceedance, but not both (Table 18, Figure 13). If a lower value is triggered such as 

the $15,000 mitigation for a rare threshold exceedance at a single turbine in two consecutive 

years or a systematic threshold exceedance with all turbines pooled in any two consecutive 

years, then the payment will be the maximum cap of $20,000 less any prior payments in that 

same year or $5,000 (Table 18, Figure 13). 

Table 18. Mitigation Schedule for Non-eagle Birds 

Event Type Description Mitigation 

First occurrence at that turbine (e.g., Year 1) $10,000 

Rare 

(single turbine) 

Two time occurrence at the same turbine in any two consecutive 

years (e.g., Years 1 and 2) $15,000 

Second time occurrence at the same turbine in same season of any 

two consecutive years (e.g., summer Year 1 and summer Year 2) $20,000 

Third time occurrence at the same turbine in any three consecutive 

years (e.g., Years 1, 2, and 3) $25,000 

Annual occurrence (e.g., Year 1) $10,000 

Systematic 

(all turbines 

pooled) 

Any two consecutive years (e.g., Years 1 and 2) $15,000 

Annual occurrence in any two consecutive years with concentration in 

same season (e.g., spring in Year 1 and spring in Year 2) $20,000 

Any three consecutive years (e.g., Years 1, 2, and 3) $25,000 

97 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Mitigation levels and payments amounts for threshold exceedance of subgroups would apply in 

the same manner as for exceedance of the general non-eagle bird thresholds (Table 18). 

However, in the case of the sensitive species subgroup, funds to which the payments are 

directed would be specific to benefiting the sensitive species identified at the Project. 

98 December 2012 
Rare Threshold Systematic Threshold 

Project becomes operational 

Year 1 

Thresholds not exceeded Thresholds not exceeded 

Initial 

monitoring 

Year 2 

Initial 

monitoring 

Year 3 

Responsive 

monitoring 

in fall 

Year 4 

Responsive 

monitoring 

in fall 

Year 5 

Long-term 

monitoring 

No mitigation required 

All-bird threshold exceeded: found 

14 dead birds at Turbine 37 during 

one search period in September 

Payment of $10,000 (first 

occurrence at that turbine) and 

responsive monitoring triggered for 

fall in Year 3 

Raptor threshold exceeded: found 

3 American kestrels at Turbine 26 

during one search period in 

October 

Payment of $10,000 (first 

occurrence at that turbine) and 

responsive monitoring triggered for 

fall in Year 4 

Thresholds not exceeded 

No mitigation required 

Threshold not exceeded 

No mitigation required. 

No mitigation required 

All-bird threshold exceeded: annual 

fatality estimate of 8 birds/turbine 

(most in fall) 

Payment of $10,000 (first 

occurrence) and responsive 

monitoring triggered for fall in Year 3 

All-bird threshold exceeded: annual 

fatality estimate of 7 birds/turbine 

(based on extrapolation of fall 

estimate). 

Payment of $15,000 (2nd consecutive 

year in same season, mitigation cap 

reached) and responsive monitoring 

triggered for fall in Year 4 

Thresholds not exceeded 

No mitigation required 

Sensitive species threshold 

exceeded: 3 dead burrowing owls 

and a gilded flicker are found 

Payment of $10,000 (first 

occurrence) targeted to benefit the 

affected sensitive species. No 

responsive monitoring triggered. 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Figure 13 Flowchart of Example Non-eagle Bird Mitigation Over First Five Years of Project 

Operation 

99 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

8.11 Responsive Monitoring 

If initial or long-term standardized post-construction fatality monitoring indicates that an eagle 

fatality has occurred or designated non-eagle bird thresholds have been exceeded (systematic 

or rare) in a given year, BP Wind Energy will conduct additional responsive fatality monitoring in 

the subsequent year to identify the cause of the eagle fatality or threshold exceedance. 

Responsive monitoring will focus on the specific location and season in which the eagle fatality 

or threshold exceedance occurred; therefore, effort may be reduced in temporal or spatial 

scales compared to initial monitoring. As mentioned above, BP Wind Energy will investigate 

eagle fatalities and threshold exceedances quickly rather than waiting for the annual report. 

9 REPORTING 

An annual post-construction fatality monitoring report will be prepared for each year the surveys 

are conducted to summarize non-eagle and eagle fatalities (if any) associated with operations of 

the Project (Table 19). In years with initial, long-term, or responsive monitoring this report will 

include a detailed summary of the methods; results from carcass searches, carcass persistence 

trials, and searcher efficiency trials; an estimate of fatalities on a per turbine and per megawatt 

basis; and discussions of the results in the context of adaptive management thresholds. In years 

with only WIRS monitoring the report will be limited to details of the fatalities detected. Annual 

reports will be provided to USFWS, AZGFD, BLM, and Reclamation for review, and will be used 

to inform eagle take permit applications if and when they are pursued (Table 19). 

BP Wind Energy will identify and report any threshold exceedances promptly after analysis and 

will not wait until the end of the annual reporting period if the potential to exceed the threshold 

occurs prior to the end of each annual reporting period. Any incident involving a threatened or 

endangered bird species or a bald or golden eagle will be reported to the USFWS, AZGFD, 

BLM, and Reclamation (depending on location of incident) within 24 hours of 

detection/discovery of a confirmed threatened, endangered, or eagle species. 

In years when eagle mitigation is conducted eagle mitigation activities will be reported either as 

part of the mortality monitoring report, or in a separate report, depending on the timing of 

completion of the two activities. Reporting for eagle mitigation will include a summary of the 

methods and results including the number and type of carcasses removed, the number of 

eagles observed during surveys, and eagle use of carcasses. This report will be provided to 

USFWS, AZGFD, BLM, and Reclamation for review. 

100 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Table 19. Example Timeline for Reporting and Eagle Take Permitting 

Permit Period Reporting/Permitting Activity1 Timeframe2 

Submission of Year 1 annual report of 

standardized fatality monitoring and WIRS 

results 

Q1 Year 2 

Submission of Year 2 annual report of 

standardized fatality monitoring and WIRS 

results 

Q1 Year 3 

Eagle Take Permit duration of 5 

years (as of 2012): 

Years 1-5 

Submission of Year 3 annual report of WIRS 

results and responsive monitoring, if 

performed 

Q1 Year 4 

Submission of Year 4 annual report of WIRS 

results and responsive monitoring, if 

performed 

Q1 Year 5 

Initiation and submission of information 

relevant to an Eagle Take Permit 

application/renewal if permit is pursued 

Q1-Q2 Year 5 

Review and processing of information 

relevant to an Eagle Take Permit 

application/renewal if permit is pursued 

Q3-Q4 Year 5 

Anticipated Eagle Take Permit 

duration for life of project, if permit 

Submission of annual report of standardized 

fatality monitoring and WIRS results for Years 

5, 10, 15, 20 and 25 

Q1 of following 

year 

is pursued: 

Years 6-30 

Submission of annual report of WIRS results 

(and responsive monitoring if performed) for 

Years 7-9, 11-14, 16-19, 21-24, 26-30 

Q1 of following 

year 

1. Reporting of any incident involving a threatened, endangered, or eagle species will occur within 24 hours of 

detection/discovery of a confirmed threatened, endangered or eagle species. 

2. Q = quarter of calendar year 

10 DECOMMISSIONING 

The Project is anticipated to have a lifetime of up to 30 years after which it may no longer be 

cost-effective to continue operations. The Project will then be decommissioned, and the existing 

equipment removed. At that time, a Decommissioning Plan will be provided and will address the 

procedures described in this section. 

The goal of Project decommissioning is to remove the installed power generation equipment 

and return the site to a condition as close to a pre-construction state as feasible. The major 

activities required for the decommissioning are as follows: 

 Remove wind turbines and met towers; 

 Remove electrical system; 

 Remove structural foundation per requirements in ROW grants; 

 Remove roads not desired for other purposes; 

 Re-grade and re-contour the disturbed area; and 

 Re-vegetate with native species. 

101 December 2012 
Mohave County Wind Farm	 Eagle Conservation Plan and Bird Conservation Strategy 

Once the Project and transmission line are de-energized, the substations, switchyard, steel 

structures, and control building will be disassembled and removed from the site. The fence and 

fence posts will be removed around the O&M building. The gravel placed at Project facilities will 

be removed and replaced with native rock, if surface rock is prevalent in the immediate area. 

BLM and Reclamation will be consulted to determine if the buried substation grounding grid 

should be removed or left in place. Assuming the transmission line no longer serves a purpose 

for the site or transmission provider, it will be disassembled and removed with the foundations. 

The transmission line tower structures will then be disassembled. The areas around the 

transmission line poles including access roads, will be returned to the pre-construction condition 

to the maximum extent feasible. 

The following BMPs from Appendix B of the Draft EIS will also be followed: 

	 Prior to the termination of the rights-of-way authorization, a decommissioning plan shall 

be developed and approved by the BLM. The decommissioning plan shall include a site 

reclamation plan and monitoring program. 

	 All management plans, BMPs, and stipulations developed for the construction phase 

shall be applied to similar activities during the decommissioning phase. 

	 All turbines and ancillary structures shall be removed from the site. 

	 Topsoil from all decommissioning activities shall be salvaged and reapplied during final 

reclamation. 

	 All areas of disturbed soil shall be reclaimed using weed-free native shrubs, grasses, 

and forbs. 

	 The vegetation cover, composition, and diversity shall be restored to values 

commensurate with the ecological setting. 

11 LITERATURE CITED 

ADOT (Arizona Department of Transportation). 2011. Arizona motor vehicle crash facts. 

Accessed October 2011. http://www.azdot.gov/mvd/statistics/crash/index.asp. 

Anderson, R., J. Tom, N. Neumann, W.P. Erickson, M.D. Strickland, M. Bourassa, K.J. Bay and 

K.J. Semka. 2005. Avian Monitoring and Risk Assessment at the San Gorgonio Wind 

Resource Area: Phase I and Phase II Field Work. Prepared for the National Renewable 

Energy Laboratory, Golden, CO. Subcontract No(s). TAM-7-16454-01, ZAT-6-15179-02. 

138 pgs. 

APLIC (Avian Power Line Interaction Committee). 2006. Suggested practices for raptor 

protection on power Lines; the State of the Art in 2006. Edison Electric Institute, APLIC 

and the California Energy Commission Washington, D.C and Sacramento, CA. 

Arnett, E.B., W.P. Erickson, J. Kerns, and J. Horn. 2005. Relationships between bats and wind 

turbines in Pennsylvania and West Virginia: An assessment of bat fatality search 

protocols, patterns of fatality, and behavioral interactions with wind turbines. A final 

report submitted to the Bats and Wind Energy Cooperative. Bat Conservation 

International, Austin, Texas, USA. 

102	 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Arnett, E.B., D.B. Inkley, D.H. Johnson, R.P. Larkin, S. Manes, A.M. Manville, J.R. Mason, M.L. 

Morrison, M.D. Strickland, and R. Thresher. 2007. Impacts of wind energy facilities on 

wildlife and wildlife habitat. Wildlife Society Technical Review 07-2. The Wildlife Society, 

Bethesda, MA. 

Arnett, E.B., M.R. Schirmacher, M.M.P. Huso, and J.P. Hayes. 2009. Patterns of bat fatality at 

the Casselman Wind Project in South-Central Pennsylvania. Annual report prepared for 

the Bats and Wind Energy Cooperative (BWEC) and the Pennsylvania Game 

Commission. 

AZGFD (Arizona Game and Fish Department). 2009. Burrowing owl project clearance guidance 

for landowners. Arizona Burrowing Owl Working Group, January 2009, 9 pp. 

AZGFD. 2010. State Wildlife Action Plan Species of Greatest Conservation Need. Revised 

December 2010. Phoenix, Arizona. 

AZGFD. 2011a. Evaluation of measures to promote desert bighorn sheep highway permeability 

post construction – Year 1 U.S. Highway 93. Quarterly report – October 2011. Presented 

to the Arizona Department of Transportation. 

AZGFD. 2011b. Arizona Golden Eagle Nest Survey 2011. Technical Report 267. Nongame and 

Endangered Wildlife Program. Phoenix, Arizona. December 2011. 

AZGFD. 2012a. Habimap Arizona. http://habimap.org/habimap/. 

AZGFD. 2012b. Draft Strategy for Reducing Golden Eagle Fatalities on Roadways through 

Roadside Carcass Removal: A Compensatory Mitigation Option For Wind Energy 

Projects. Phoenix, Arizona. July 23, 2012. 

BHE Environmental, Inc. 2011. Post-Construction Bird and Bat Mortality Study: Cedar Ridge 

Wind Farm, Fond Du Lac County, Wisconsin. Final Report. Prepared for Wisconsin 

Power and Light, Madison, Wisconsin. Prepared by BHE Environmental, Inc. Cincinnati, 

Ohio. February 2011. 

Bates, J. W. and M. O. Moretti. 1994. Golden eagle (Aquila chrysaetos) population ecology in 

eastern Utah. Great Basin Naturalist. 54:248-255. 

Beason, Robert C. 1995. Horned Lark (Eremophila alpestris), The Birds of North America 

Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of 

North America Online: 

http://bna.birds.cornell.edu.bnaproxy.birds.cornell.edu/bna/species/195. 

doi:10.2173/bna.195 

Bissonette, J. and C. Kassar. 2008. Locations of deer–vehicle collisions are unrelated to traffic 

volume or posted speed limit. Human–Wildlife Conflicts 2:122–130. 

Bissonette, J.A., C.A. Kassar, and L.J. Cook. 2008. Assessment of costs associated with deervehicle collisions: human death and injury, vehicle damage, and deer loss. HumanWildlife Conflicts 2:17-27. 

Bittner, D. and C. Meador. 2011. Golden eagle status in selected areas of the west. Presented 

at the Western Raptor Symposium. Riverside, California, USA. February 8-9, 2011. 

103 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Boeker, E.L. 1974. Status of golden eagle surveys in the western states. Wildlife Society 

Bulletin 2:46-49. 

Boeker, E.L. and E.B. Bolen. 1972. Winter golden eagle populations in the southwest. Journal of 

Wildlife Management 36:477-484. 

BLM (Bureau of Land Management). 2012. Mohave County Wind Farm Project 

Draft Environmental Impact Statement. U.S. Department of the Interior, Bureau of Land 

Management, Colorado River District. Kingman Field Office, Kingman, Arizona. 

Available at http://www.blm.gov/az/st/en/prog/energy/wind/mohave/reports/DEIS.html 

Accessed on April 29, 2012. 

BLM. 2010a. Instruction Memorandum No. 2010-156. BLM Bald and Golden Eagle Protection 

Act – Golden Eagle National Environmental Policy Act and Avian Protection Plan 

Guidance for Renewable Energy. Issued July 9, 2010. 

BLM. 2010b. Instruction Memorandum No. AZ-2011-005: Updated Bureau of Land Management 

(BLM) Sensitive Species List for Arizona. BLM Arizona State Office, Phoenix, AZ.BLM. 

2012. Draft Environmental Impact Statement for the Proposed Mohave County Wind 

Farm Project. Kingman Field Office, Arizona. 

Call, M. 1979. Habitat management guides for birds of prey. Bureau of Land Management. 

Technical. Note 338. Denver, Colorado. 

Craig, E.H., and T.H. Craig. 1998. Lead and mercury levels in golden and bald eagles and 

annual movements of golden eagles wintering in east central Idaho 1990-1997. 

Submitted to: Allan Thomas, Idaho State Office, Bureau of Land Management. 

Craighead, A.C., F.L. Craighead, and L. Oechsli. 2009. Bozeman Pass wildlife pre- and postfence monitoring project. Proceedings from the International Conference on Wildlife 

Ecology and Transportation. Duluth, Minnesota. 

Derby, C., A. Dahl, W. Erickson, K. Bay, and J. Hoban. 2007. Post-Construction Monitoring 

Report for Avian and Bat Mortality at the NPPD Ainsworth Wind Farm. Unpublished 

report prepared by Western EcoSystems Technology, Inc. (WEST), Cheyenne, 

Wyoming, for the Nebraska Public Power District. 

Dodd, N.L. and J.W. Gagnon. 2010. Arizona State Route 260: promoting wildlife permeability, 

highway safety, and agency cultural change. Pages 257-274 in Highways, Wildlife, and 

Habitat Connectivity (J.P. Beckmann, A.P. Clevenger, M. Huijser, eds). 

Dodd, N. L., J. W. Gagnon, S. Boe, A. Manzo, and R. E. Schweinsburg. 2007. Evaluation of 

measures to minimize wildlife-vehicle collisions and maintain wildlife permeability across 

highways – State Route 260, Arizona, USA. Arizona Transportation Research Center, 

Arizona Department of Transportation, Phoenix, Arizona, USA. 

Drewitt, A.L., and R.H.W. Langston. 2006. Assessing the impacts of wind farms on birds. Ibis 

148:29-42. 

Driscoll, D.E. 2010. Protocol for golden eagle occupancy, reproduction, and prey population 

assessment. American Eagle Research Institute, Apache Junction, Arizona. 

104 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Driscoll, J. 2005. Golden Eagle.in T. E. Corman and C. Wise-Gervais, editors. The Arizona 

Breeding Bird Atlas. University of New Mexico Press, Albuquerque. 

Dussault, C., M. Poulin, R. Courtois, and J-P Ouellet. 2006. Temporal and spatial distribution of 

moose-vehicle accidents in the Laurentides Wildlife Reserve, Quebec, Canada. Wildlife 

Biology 12:415-425. 

Eakle, W.L., E. L. Smith, S.W. Hoffman, D.W. Stahlecker, and R.B. Duncan. 1996. Results of a 

raptor survey in southwestern New Mexico. Journal of Raptor Research 30:183-188. 

Enk, T., K. Bay, M. Sonnenberg, and J.R. Boehrs. 2012a. Year 2 Post-Construction Avian and 

Bat Monitoring Report: Biglow Canyon Wind Farm Phase II, Sherman County, Oregon. 

September 13, 2010 - September 15, 2011. Prepared for Portland General Electric 

Company, Portland, Oregon. Prepared by Western EcoSystems Technology, Inc. 

(WEST), Cheyenne, Wyoming, and Walla Walla, Washington. January 7, 2011. 

Enk, T., K. Bay, M. Sonnenberg, and J.R. Boehrs. 2012b. Year 1 Avian and Bat Monitoring 

Report: Biglow Canyon Wind Farm Phase III Sherman County, Oregon. September 13, 

2010 - September 9, 2011. Prepared for Portland General Electric Company, Portland, 

Oregon. Prepared by Western EcoSystems Technology, Inc. (WEST), Cheyenne, 

Wyoming, and Walla Walla, Washington. April 24, 2012. 

Erickson, W.P. 2007. Summary of Methods and Results for Prediction and Estimation of 

Impacts and Risk. Presented at NWCC Probability of Impact Workshop, 13 November 

2007, Golden, CO. 

Erickson, W.P., G.D. Johnson, M.D. Strickland, and K. Kronner. 2000. Avian and Bat Mortality 

Associated with the Vansycle Wind Project, Umatilla County, Oregon: 1999 Study Year. 

Technical report prepared by WEST, Inc. for Umatilla County Department of Resource 

Services and Development, Pendleton, Oregon. 21pp. http://www.westinc.com/reports/vansyclereportnet.pdf. 

Erickson, W.P., G.D. Johnson, M.D. Strickland, D.P. Young, K.J. Sernka, and R.E. Good. 

2001a. Avian collisions with wind turbines: a summary of existing studies and 

comparisons to other sources of avian collision mortality in the United States. Prepared 

for the National Wind Coordinating Committee. Western Ecosystems Technology, 

Cheyenne, Wyoming, USA., http://www.west-inc.com/reports/avian_collisions.pdf.. 

Accessed 1 May 2007. 

Erickson, W.P., E. Lack, M. Bourassa, K. Sernka, and K. Kronner. 2001b. Wildlife Baseline 

Study for the Nine Canyon Wind Project, Final Report May 2000-October 2001 

Technical report prepared for Energy Northwest, Richland, Washington. 

Erickson, W.P., G. Johnson, D. Young, D. Strickland, R. Good, M. Bourassa, K. Bay, and K. 

Sernka. 2002. Synthesis and comparison of baseline avian and bat use, raptor nesting 

and mortality information from proposed and existing wind developments. Technical 

report prepared by WEST, Inc., for Bonneville Power Administration, Portland, OR. 

Erickson, W.P., K. Kronner, and B. Gritski. 2003a. Nine Canyon Wind Power Project avian and 

bat monitoring report. September 2002 – August 2003. Prepared for the Nine Canyon 

Technical Advisory Committee and Energy Northwest by Western EcoSystems 

105 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Technology, Inc. (WEST), Cheyenne, Wyoming, and Northwest Wildlife Consultants 

(NWC), Pendleton, Oregon. 

Erickson, W.P., D.P. Young, Jr., G. Johnson, J. Jeffrey, K. Bay, R. Good, and H. Sawyer. 

2003b. Wildlife Baseline Study for the Wild Horse Wind Project. Summary of Results 

from 2002-2003 Wildlife Surveys May 10, 2002- May 22, 2003. Draft report prepared for 

Zilkha Renewable Energy, Portland, Oregon. Prepared by Western EcoSystems 

Technology, Inc. (WEST), Cheyenne, Wyoming. November 2003. 

Erickson, W.P., J. Jeffrey, K. Kronner, and K. Bay. 2003c. Stateline Wind Project Wildlife 

Monitoring Annual Report, Results for the Period July 2001 – December 2002. Technical 

report submitted to FPL Energy, the Oregon Office of Energy, and the Stateline 

Technical Advisory Committee. 

Erickson, W.P., J. Jeffrey, K. Kronner, and K. Bay. 2004. Stateline Wind Project Wildlife 

Monitoring Final Report, July 2001—December 2003. Technical report peer- reviewed 

by and submitted to FPL Energy, the Oregon Energy Facility Siting Council, and the 

Stateline Technical Advisory Committee. 

Erickson, W.P., G.D. Johnson, and D.P. Young, Jr. 2005. A summary and comparison of bird 

mortality from anthropogenic causes with an emphasis on collisions. USDA Forest 

Service Gen. Tech. Rep. PSW-GTR-191. 

Erickson, W.P., K. Kronner, and K.J. Bay. 2007. Stateline Wind Project Wildlife Monitoring 

Annual Report, January – December 2006. Technical report submitted to FPL Energy, 

the Oregon Energy Facility Siting Council, and the Stateline Technical Advisory 

Committee. 40 pgs. 

Erickson, W.P., J. Jeffrey, and V.K. Poulton. 2008. Avian and Bat Monitoring: Year 1 Report. 

Puget Sound Energy Wild Horse Wind Project, Kittitas County, Washington. Prepared 

for Puget Sound Energy, Ellensburg, Washington, by Western EcoSystems Technology, 

Inc. (WEST), Cheyenne, Wyoming. January 2008. 

Ferguson-Lees, J., and D. A. Christie. 2001. Raptors of the World. Houghton Mifflin, Boston. 

Ferrer, M., M. de Lucas, G. F. E. Janss, E. Casado, A. R. Muñoz, M. J. Bechard and C. P. 

Calabuig. 2012. Weak relationship between risk assessment studies and recorded 

mortality in wind farms. Journal of Applied Ecology 49: 38–46. 

Fiedler, J.K., T.H. Henry, R.D. Tankersley, and C.P. Nicholson. 2007. Results of Bat and Bird 

Mortality Monitoring at the Expanded Buffalo Mountain WindFarm, 2005. Prepared for 

the Tennessee Valley Authority, 42 pgs. 

Forman, R.T.T. and L.E. Alexander. 1998. Roads and their major ecological effects. Annual 

Review of Ecology and Systematics. 29:207-231. 

Gagnon, J.W., N.L. Dodd, S. Boe, and R.E. Schweinsburg. 2009. Using global positioning 

system technology to determine wildlife crossing structure placement and evaluating 

their success in Arizona, USA. Proceedings from the International Conference on 

Ecology and Transportation. Duluth, Minnesota. 

Gleason, J.S. and J.A. Jenks. 1993. Factors influencing deer/vehicle mortality in east central 

South Dakota. Prairie Naturalist 25:281-288. 

106 December 2012 
 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Gritski, B., K. Kronner, and S. Downes. 2008. Leaning Juniper Wind Power Project, 2006 − 

2008. Wildlife Monitoring Final Report. Prepared for PacifiCorp Energy, Portland, 

Oregon. Prepared by Northwest Wildlife Consultants, Inc. (NWC), Pendleton, Oregon. 

December 30, 2008. 

Gritski, B., S. Downes, and K. Kronner. 2010. Klondike III (Phase 1) Wind Power Project Wildlife 

Monitoring Study October 2007–October 2009. Prepared for Iberdrola Renewables, 

Klondike Wind Power III, LLC, Portland, OR. Prepared by Northwest Wildlife 

Consultants, Inc. (NWC), Pendleton, Oregon. April 21, 2010. 

Gritski, R., S. Downes, and K. Kronner. 2011. Klondike IIIa (Phase 2) Wind Power Project, 

Wildlife Monitoring August 2008 - August 2010. Prepared for Iberdrola Renewables, 

Klondike Wind Power III LLC, Portland, Oregon. Prepared by Northwest Wildlife 

Consultants, Inc. (NWC), Pendleton, Oregon. April 2011. 

Grodsky, S.M. and D. Drake. 2011. Assessing Bird and Bat Mortality at the Forward Energy 

Center. Final Report. Public Service Commission (PSC) of Wisconsin. PSC REF 

No:152052. Prepared for Forward Energy LLC. Prepared by Department of Forest and 

Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin. August 2011. 

Grovenburg, T.W., J.A. Jenks, R.W. Klaver, K.L. Monteith, D.H. Galster, R.J. Schauer, W.W. 

Morlock, and J.A. Delger. 2008. Factors affecting road mortality of white-tailed deer in 

eastern South Dakota. Human-Wildlife Conflicts 2:48-59. 

Gruver, J., M. Sonnenburg, K. Bay, and W. Erickson. 2009. Post-Construction Bat and Bird 

Fatality Study at the Blue Sky Green Field Wind Energy Center, Fond Du Lac County, 

Wisconsin July 21 - October 31, 2008 and March 15 - June 4, 2009. Unpublished report 

prepared by Western EcoSystems Technology, Inc. (WEST), Cheyenne, Wyoming. 

December 17, 2009. 

Gunther, K.A., M.J. Biel, and H.L. Robison. 1998. Factors influencing the frequency of roadkilled wildlife in Yellowstone National Park. Proceedings from the International 

Conference on Wildlife Ecology and Transportation. Fort Myers, Florida. 

Harmata, A.R. 2002. Encounters of golden eagles banded in the Rocky Mountain West. Journal 

of Field Ornithology 73:23-32. 

HDMS (Heritage Data Management System). 2012. Data requests of the Arizona HDMS for the 

Mohave County Wind Farm. 

Holmes, T.L., R.L. Knight, L. Stegall, and G.R. Craig. 1993. Responses of wintering grassland 

raptors to human disturbance. Wildlife Society Bulletin 21:461-468. 

Howe, R.W., W. Evans, and A.T. Wolf. 2002. Effects of Wind Turbines on Birds and Bats in 

Northeastern Wisconsin. Prepared by University of Wisconsin-Green Bay, for Wisconsin 

Public Service Corporation and Madison Gas and Electric Company, Madison, 

Wisconsin. November 21, 2002. 104 pp. 

Howell, J.A. and J. Noone. 1992. Examination of avian use and mortality at a U.S. windpower 

wind energy development site, Montezuma Hills, Solano County, California. Final report 

to Solano County Department of Environmental Management, Fairfield, California. 

107 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Hunt, G. 2002. Golden eagles in a perilous landscape: predicting the effects of mitigation for 

wind turbine blade-strike mortality. Consultant Report, California Energy Commission. 

Huso, M.M.P. 2011. An estimator of wildlife fatality from observed carcasses. Environmetrics 

22:318-329. 

Insignia Environmental. 2009. 2008/2009 Annual Report for the Buena Vista Avian and Bat 

Monitoring Project. Prepared for Contra Costa County, Martinez, CA. 95 pgs. 

Jacques Whitford (Jacques Whitford Stantec Limited). 2009. Ripley Wind Power Project 

Postconstruction Monitoring Report. Project No. 1037529.01. Report to Suncor Energy 

Products Inc., Calgary, Alberta, and Acciona Energy Products Inc., Calgary, Alberta. 

Prepared for the Ripley Wind Power Project Post-Construction Monitoring Program. 

Prepared by Jacques Whitford, Markham, Ontario. April 30, 2009. 

www.jacqueswhitford.com. 

Jain, A. 2005. Bird and Bat Behavior and Mortality at a Northern Iowa Windfarm. M.S. Thesis. 

Iowa State University, Ames, Iowa. 

Jain, A., P. Kerlinger, R. Curry, and L. Slobodnik. 2007. Annual Report for the Maple Ridge 

Wind Power Project post-construction bird and bat fatality study—2006. Prepared by 

Curry and Kerlinger, LLC for PPM Energy, Horizon Energy, and Technical Advisory 

Committee for the Maple Ridge Project. 

Jain, A., P. Kerlinger, R. Curry, L. Slobodnik, and M. Lehman. 2009. Maple Ridge Wind Power 

Avian and Bat Fatality Study Report - 2008. Annual Report for the Maple Ridge Wind 

Power Project, Post-construction Bird and Bat Fatality Study - 2008. Prepared for 

Iberdrola Renewables, Inc., Horizon Energy, and the Technical Advisory Committee 

(TAC) for the Maple Ridge Project Study. Prepared by Curry and Kerlinger, LLC. May 

14, 2009. 

Jain, A.A., R.R. Koford, A.W. Hancock, and G.G. Zenner. 2011. Bat Mortality and Activity at a 

Northern Iowa Wind Resource Area. American Midland Naturalist. 165: 185-200. 

Jeffrey, J.D., K. Bay, W.P. Erickson, M. Sonneberg, J. Baker, M. Kesterke, J. Boehrs, and A. 

Palochak. 2009a. Portland General Electric Biglow Canyon Wind Farm Phase I PostConstruction Avian and Bat Monitoring First Annual Report, Sherman County, Oregon. 

January 2008 - December 2008. Technical report prepared for Portland General Electric 

Company, Portland, Oregon. Prepared by Western EcoSystems Technology (WEST) 

Inc., Cheyenne, Wyoming, and Walla Walla, Washington. April 29, 2009. 

Jeffrey, J.D., W.P. Erickson, K. Bay, M. Sonneberg, J. Baker, J. Boehrs, and A. Palochak. 

2009b. Horizon Wind Energy, Elkhorn Valley Wind Project, Post-Construction Avian and 

Bat Monitoring, First Annual Report, January-December 2008. Technical report prepared 

for Horizon Wind Energy, Portland, Oregon. Prepared by Western EcoSystems 

Technology, Inc., Cheyenne, Wyoming, and Walla Walla, Washington. 

Johnson, G.D., and W.P. Erickson. 2011. Avian, Bat and Habitat Cumulative Impacts 

Associated with Wind Energy Development in the Columbia Plateau Ecoregion Of 

Eastern Washington and Oregon. May 2011. Prepared for Klickitat County Planning 

Department. Prepared by Western EcoSystems Technology, Inc. (WEST). Cheyenne, 

108 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Wyoming. May 18, 2011. Available online at: 

http://www.klickitatcounty.org/Planning/filesHtml/200408-EOZ-EIS/cummulative2.pdf. 

Johnson, G.D. and S.E. Stephens. 2011. Wind Power and Bio Fuels: A Green Dilemma for 

Wildlife Conservation. Chapter 8. In: Energy Development and Wildlife Conservation in 

Western North America. D. E. Naugle, ed. Island Press, Washington, D.C. Pp. 131-155. 

Johnson, G.D., W.P. Erickson, M.D. Strickland, M.F. Shepherd, and D.A. Shepherd. 2000a. 

Avian monitoring studies at the Buffalo Ridge Wind Resource Area, Minnesota: Results 

of a 4-Year Study. Final report prepared for Northern States Power Company, 

Minneapolis, Minnesota, by Western EcoSystems Technology, Inc. (WEST), Cheyenne, 

Wyoming. 

Johnson, G.D., D.P. Young, W.P. Erickson, C.E. Derby, M.D. Strickland, and R.E. Good. 2000b. 

Wildlife Monitoring Studies, SeaWest Windpower Plant, Carbon County, Wyoming, 

1995-1999. Final report prepared for SeaWest Energy Corporation, San Diego, 

California, and the Bureau of Land Management, Rawlins, Wyoming, by Western 

EcoSystems Technology, Inc. (WEST), Cheyenne, Wyoming. 

Johnson, G.D., W.P. Erickson, M.D. Strickland, M.F. Shepherd, D.A. Shepherd, and S.A. 

Sarappo. 2002. Collision mortality of local and migrant birds at a large-scale wind power 

development on Buffalo Ridge, Minnesota. Wildlife Society Bulletin 30:879-887. 

Johnson, G.D., W.P. Erickson, and J. White. 2003. Avian and bat mortality at the Klondike 

Oregon Phase I Wind Plant, Sherman County, Oregon. Technical Report prepared for 

Northwestern Wind Power. Prepared by WEST, Cheyenne, WY. 

Kerlinger, P., R.Curry, L. Culp, A. Hasch and A. Jain. 2006a. Avian monitoring study and risk 

assessment for the Shiloh Wind Power Project, Solano County, California. Prepared for 

EnXco. 

Kerlinger, P., R. Curry, L. Culp, A. Jain, C. Wilkerson, B. Fischer, and A. Hasch. 2006b. Post 

construction avian and bat fatality monitoring study for the High Winds wind power 

project. Solano County, California: Two Year Report. Prepared for High Winds, LLC, 

FPL Energy. 

Kerlinger, P., R. Curry, L. Culp, A. Hasch and A. Jain. 2009. Post-construction avian monitoring 

study for the Shiloh I wind power project, Solano County, California. Prepared for 

Iberdrola Renewables. 

Kerns, J., and P. Kerlinger. 2004. A study of bird and bat collision fatalities at the Mountaineer 

Wind Energy Center, Tucker County, West Virginia: Annual report for 2003. Technical 

report prepared by Curry and Kerlinger, LLC for FPL Energy and Mountaineer Wind 

Energy Center Technical Review Committee. 

Kline, N.C. and D.E. Swann. 1998. Quantifying wildlife road mortality in Saguaro National Park. 

Proceedings from the International Conference on Wildlife Ecology and Transportation. 

Fort Myers, Florida. 

Kochert, M.N, K. Steenhof, C.L. McIntyre, and E.H. Craig. 2002. Golden Eagle (Aquila 

chrysaetos). In: The Birds of North America. No. 684. A. Poole and F. Gill (Eds.), 

Philadelphia, PA: The Birds of North America, Inc. 

109 December 2012 
 

Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Kronner, K., B. Gritski, J. Baker, V. Marr, G. Johnson and K. Bay. 2005. Wildlife baseline study 

for the Leaning Juniper Wind Power Project. Prepared for PPM Energy, Portland, 

Oregon and CH2M Hill, Portland, Oregon. Prepared by Northwest Wildlife Consultants, 

Inc., Pendleton, Oregon and WEST, Inc., Cheyenne, Wyoming. 

Kronner, K., R. Gritski, and S. Downes. 2008. Big Horn Wind Power Project Wildlife Fatality 

Monitoring Study: 2006−2007. Final report prepared for PPM Energy and the Big Horn 

Wind Project Technical Advisory Committee by Northwest Wildlife Consultants, Inc. 

(NWC), Mid-Columbia Field Office, Goldendale, Washington. June 1, 2008. 

Laundré, J.W. and B.L. Keller. 1984. Home-range size of coyotes: a critical review. The Journal 

of Wildlife Management 48:127-139. 

Leddy, K.L., K.F. Higgins, and D.E. Naugle. 1999. Effects of Wind Turbines on Upland Nesting 

Birds in CRP Grasslands. Wilson Bulletin 111:100-104. 

Lightfoot, D.C., A.D. Davidson, C.M. McGlone, and D.G. Parker. 2011. Rabbit abundance 

relative to rainfall and plant production in northern Chihuahuan Desert grassland and 

shrubland habitats. Western North American Naturalist 70:490–499. 

Lowe, C.H. 1985. Arizona’s Natural Environment. The University of Arizona Press. Tucson, 

Arizona. 

Marzluff, J. M., S. T. Knick, M. S. Vekasy, L. S. Schueck, and T. J. Zarriello. 1997. Spatial use 

and habitat selection of golden eagles in southwestern Idaho. Auk 114:673-687. 

McCarty, K.M. and K.V. Jacobson. 2011. Arizona golden eagle nest survey 2011 summary 

report. Nongame and Endangered Wildlife Program Technical Report 267. Arizona 

Game and Fish Department, Phoenix, Arizona. 

McIntyre, C. L. and L. G. Adams. 1999. Reproductive characteristics of migratory golden eagles 

in Denali National Park, Alaska. Condor 101:115-123. 

McShea, W.J., C.M. Stewart, L.J. Kearns, S. Liccioli, D. Kocka. 2008. Factors affecting autumn 

deer-vehicle collisions in a rural Virginia county. Human-Wildlife Conflicts 2:110-121. 

Millsap, B.A. 1981. Distributional status of Falconiformes in west central Arizona with notes on 

ecology, reproductive success, and management. United States Department of Interior, 

Bureau of Land Management, Technical Note 355. 

Millsap, B.A. and G.T. Allen. 2006. Effects of falconry harvest on wild raptor populations in the 

United States: theoretical considerations and management recommendations. Wildlife 

Society Bulletin 34:1392-1400. 

Myers, W.L., W.Y. Chang, S.S. Germaine, W.M. Vander Haegen, and T.E. Owens. 2008. An 

analysis of deer and elk-vehicle collision sites along state highways in Washington State. 

Completion Report, Washington Department of Fish and Wildlife. Olympia, WA. 

NatureServe. 2011. NatureServe Explorer: An online encyclopedia of life [web application]. 

Version 7.1. NatureServe, Arlington, Virginia. Available 

http://www.natureserve.org/explorer. Accessed on December 2011. 

NCDC (National Climatic Data Center). 2011. Climate Data Online. Available at: 

http://www7.ncdc.noaa.gov/CDO/cdo. 

110 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Nicholson, C.P., J. R.D. Tankersley, J.K. Fiedler, and N.S. Nicholas. 2005. Assessment and 

Prediction of Bird and Bat Mortality at Wind Energy Facilities in the Southeastern United 

States. Final Report. Tennessee Valley Authority, Knoxville, Tennessee. 

Nielson, R.M., T. Rintz, L. McManus, and L.L. McDonald. 2012. A survey of golden eagles 

(Aquila chrysaetos) in the western US: 2011 Annual Report. Report prepared by 

Western EcoSystems Technology, Inc. for the US Fish and Wildlife Service. 

North American Bird Conservation Initiative (NABCI). 2000. Bird Conservation Regions. 

Available at: http://www.nabci-us.org/bcrs.htm. Accessed on June 26, 2012. 

NWC (Northwest Wildlife Consultants, Inc.) and WEST (Western EcoSystems Technology, 

Inc.). 2007. Avian and Bat Monitoring Report for the Klondike II Wind Power Project. 

Sherman County, Oregon. Prepared for PPM Energy, Portland, Oregon. Managed and 

conducted by NWC, Pendleton, Oregon. Analysis conducted by WEST, Cheyenne, 

Wyoming. July 17, 2007. 

Olendorff, R. R., and W. D. Zeedyk. 1978. Land management for the conservation of 

endangered birds. Pp. 419-428 in S. A. Temple Editor. Endangered birds. University of 

Wisconsin Press, Madison, Wisconsin. 

Oregon EFSC (Oregon Energy Facility Siting Council). 2009a. Golden Hills Wind Project: 

Wildlife Monitoring and Mitigation Plan. 

Oregon EFSC. 2009b. Leaning Juniper II Wind Project: Wildlife Monitoring and Mitigation Plan. 

Oregon EFSC. 2010. Montague Wind Power Facility: Wildlife Monitoring and Mitigation Plan. 

Pagel, J.E., D.M. Whittington and G.T. Allen. 2010. Interim golden eagle inventory and 

monitoring protocols; and other recommendations. Division of Migratory Birds, U.S. Fish 

and Wildlife Service. 

Pagel, J.E., B.A. Millsap, E. Kernsher, S. Covenington, and R. Murphy. 2011. Known eagle 

mortalities at wind turbine technology facilities in the western United States. Raptor 

Research Foundation Meetings, Duluth, Minnesota, October 2011. 

Palmer, R.S. 1988. Golden Eagle. Pages 180-231 in R. Palmer (ed.), Handbook of North 

American Birds. Vol. 5. Yale Univ. Press, New Haven, Connecticut. 

Peterson Guides. 2011. Bird Finder List for Mohave County Arizona. Peterson Guides, Cornell 

Laboratory of Ornithology, and Appweavers, Inc. Available at 

http://petersonguides.com/BirdFinder/counties/AZ-015.html. Accessed online August 7, 

2012. 

Phillips R.L. 1986. Current issues concerning the management of golden eagles in the western 

U.S.A. Birds of Prey Bulletin 3:149-156. 

Poulton, V. 2010. Summary of Post-Construction Monitoring at Wind Projects Relevant to 

Minnesota, Identification of Data Gaps, and Recommendations for Further Research 

Regarding Wind-Energy Development in Minnesota. Prepared for State of Minnesota 

Department of Commerce. 52 Pgs. 

Reynolds, R.T., J.M. Scott, and R.A. Nussbaum. 1980. A Variable Circular-Plot Method for 

Estimating Bird Numbers. Condor 82(3): 309-313. 

111 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Rich, T.D., C.J. Beardmore, H. Berlanga, P.J. Blancher, M.S.W. Bradstreet, G.S. Butcher, D.W. 

Demarest, E.H. Dunn, W.C. Hunter, E.E. Iñigo-Elias, J.A. Kennedy, A.M. Martell, A.O. 

Panjabi, D.N. Pashley, K.V. Rosenberg, C.M. Rustay, J.S. Wendt, T.C. Will. 2004. 

Partners in Flight North American Landbird Conservation Plan. Cornell Lab of 

Ornithology. Ithaca, NY. 

Robinson, S.K., F.R. Thompson III, T.M. Donovan, D. R. Whitehead, and J. Faaborg. 1995. 

Regional forest fragmentation and the nesting success of migratory birds. Science 267: 

1987-1990. 

Rudnick, J.A., T.E. Katzner, E.A. Bragin, O.E. Rhodes, and J.A. Dewoody. 2005. Using naturally 

shed feathers for individual identification, genetic parentage analyses, and population 

monitoring in an endangered Eastern imperial eagle (Aquila heliaca) population from 

Kazakhstan. Molecular Ecology 14:2959-2967. 

Russell, A.C. and J.E. Harden. 2009. RAVEN project: application of WRI rehabilitation 

acquisition data to state endangered and threatened species and species of 

conservation concern. Report to New Mexico Department of Fish and Game, Share With 

Wildlife Program. 

Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2011. 

The North American Breeding Bird Survey, Results and Analysis 1966 - 2010. Version 

12.07.2011 USGS Patuxent Wildlife Research Center, Laurel, MD. Available at 

http://www.mbr-pwrc.usgs.gov/bbs/bbs.html. Accessed on September 17, 2012. 

Smallwood, S.K. and B. Karas. 2009. Avian and Bat Fatality Rates at Old-Generation and 

Repowered Wind Turbines in California. Journal of Wildlife Management 73(7):1062– 

1071. 

Shaffer, J., and D. Johnson. 2008. Displacement Effects of Wind Developments on Grassland 

Birds in the Northern Great Plains. NWCC Wind Wildlife Conference, October 2008. 

Milwaukee, WI. 

SGEMC (Southwestern Golden Eagle Management Committee). 2011. Arizona golden eagle 

survey and monitoring protocol. Developed by the Southwestern Golden Eagle 

Management Committee Science Subcommittee, April 2011. 

SGEMC. 2012. Golden Eagle Nest Survey Results. Unpublished report. 

Steenhoff, K., M.N. Kochert and T.L. MacDonald. 1997. Interactive effects of prey and weather 

on golden eagle reproduction. Journal of Animal Ecology 66:350-362. 

Strickland, M.D., E.B. Arnett, W.P. Erickson, D.H. Johnson, G.D. Johnson, M.L., Morrison, J.A. 

Shaffer, and W. Warren-Hicks. 2011. Comprehensive Guide to Studying Wind 

Energy/Wildlife Interactions. Prepared for the National Wind Coordinating Collaborative, 

Washington, D.C., USA. 

Suter, G.W., H, and J.L. Joness. 1981. Criteria for golden eagle, ferruginous hawk, and prairie 

falcon nest site protection. Journal of Raptor Research 15:12-18. 

Taylor, K., J. Gruver, and K. Bay. 2008. Wildlife Studies for the Campbell Hill Wind Resource 

Area, Converse County, Wyoming. Fall Summary Report: September 9 - November 5, 

112 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

2008. Prepared for Three Buttes Windpower, LLC/Duke Energy. Prepared by Western 

EcoSystems Technology, Inc.(WEST), Cheyenne, Wyoming. December 30, 2008 

Tetra Tech. 2011. AWEA report on eagle citations, nest locations, and fatalities. Report 

prepared for the American Wind Energy Association. 

Tetra Tech. 2012. Mohave County Wind Farm 2012 Golden Eagle Surveys January – May, 

2012. Prepared for BP Wind Energy North America Inc. Prepared by Tetra Tech EC, Inc. 

June 2012. 

Thompson, J. 2011. Raptor nest survey for the proposed Mohave County Wind Resource Area, 

Mohave County, Arizona. Report prepared for BP Wind Energy. 

Thompson, J. D. Solick, J. Gruver, and K. Bay. 2011a. Wildlife baseline studies for the Mohave 

County Wind Farm, Mohave County, Arizona. Final report prepared for BP Wind Energy. 

Thompson, J. D. Solick, and K. Bay. 2011b. Post-construction fatality surveys for the Dry Lake 

Phase I Wind Project Iberdrola Renewables September 2009 – December 2010. 

Prepared for Iberdrola Renewables. 

Tierney, R. 2009. Buffalo Gap 2 Wind Farm Avian Mortality Study: July 2007 - December 2008. 

Final Survey Report. Submitted by TRC, Albuquerque, New Mexico. TRC Report No. 

151143-B-01. June 2009. 

TRC Environmental Corporation. 2008. Post-Construction Avian and Bat Fatality Monitoring and 

Grassland Bird Displacement Surveys at the Judith Gap Wind Energy Project, 

Wheatland County, Montana. Prepared for Judith Gap Energy, LLC, Chicago, Illinois. 

TRC Environmental Corporation, Laramie, Wyoming. TRC Project 51883-01 (112416). 

January 2008. http://www.newwest.net/pdfs/AvianBatFatalityMonitoring.pdf. 

USEPA (US Environmental Protection Agency). 2007. Level III and IV Ecoregions. National 

Health and Environmental Effects Research Laboratory, USEPA. Available online at: 

http://www.epa.gov/wed/pages/ecoregions/level_iii.htm. Accessed online May 31, 2012. 

USFWS (US Fish and Wildlife Service). 2008. Birds of Conservation Concern 2008. United 

States Department of Interior, Fish and Wildlife Service, Division of Migratory Bird 

Management, Arlington, Virginia. 85 pp. Available online at: 

http://www.fws.gov/migratorybirds/ 

USFWS. 2009. Eagle permits; Take necessary to protect interests in particular localities; final 

rule. Federal register. 74:46836-46879. 

USFWS. 2010. Discussions on recent range and use areas of released California condors in 

Arizona. Communication between URS and the USFWS, April 2010. 

USFWS. 2011a. Draft eagle conservation plan guidance. Released January, 2011. 

USFWS. 2011b. Eagle Conservation Plan Review and Sufficiency Checklist –Wind Energy 

Projects. USFWS Region 2. Version dated August 24, 2011. 

USFWS. 2012a. Draft eagle conservation plan guidance version 2. Technical Appendices. 

Released August 2012. 

113 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

USFWS. 2012b. U.S. Fish and Wildlife Service Final Land-Based Wind Energy Guidelines. 

Available from: http://www.fws.gov/windenergy/docs/WEG_final.pdf Accessed March 

2012. 

USGS (US Geological Survey). 1999. 10 meter National Elevation Dataset. 7.5-minute elevation 

data for the conterminous US. Sioux Falls, South Dakota: US Geological Survey. 

USGS. 2010. Bird banding laboratory band returns for eagles 1960-2010 (unpublished data). 

Received by Tetra Tech EC, December 20 2010. 

University of California Museum of Paleontology. 2012. The Desert Biome. Available at 

http://www.ucmp.berkeley.edu/exhibits/biomes/deserts.php Accessed on August 9, 

2012. 

Watson, J. 1997. The golden eagle. 1st ed. T and A. D. Poyser, London, United Kingdom. 

Watson, J.W., A.A. Duff, and R.W. Davies. 2012. Breeding range characteristics and resource 

use of Golden Eagles in Washington and implications for wind turbine placement. 

Presentation at The Wildlife Society Annual Meeting on October 17, 2012 in Portland, 

Oregon. 

WEST (Western Ecosystems Technology, Inc.). 2006. Diablo Winds Wildlife Monitoring 

Progress Report March 2005 - February 2006. 32 pgs. 

WEST. 2008. Diablo Winds Wildlife Monitoring Progress Report: March 2005 – February 2007. 

Prepared by WEST, Cheyenne, Wyoming. August 2008. 

WEST. 2011. Presentation at the Northwest Wind Energy and Wildlife Workshop. Portland, 

Oregon. June 7-8, 2011. 

WRCC (Western Regional Climate Center). 2012. Climatological Summary: Boulder City, NV, 

Temple Bar, AZ, Yucca, AZ, Searchlight, NV, Kingman, AZ, Kingman 2, AZ. Available 

online at http://www.wrcc.dri.edu/summary/igm.az.html. Accessed on May 31, 2012. 

Whitfield, D. P. 2009. Collision avoidance of golden eagles at wind farms under the ‘Band’ 

collision risk model. Report from Natural Research to Scottish Natural Heritage, 

Banchory, UK. 

Young, D.P. Jr., W.P. Erickson, K. Bay, J. Jeffrey, E.G. Lack, R.E. Good, and H.H. Sawyer. 

2003a. Baseline Avian Studies for the Proposed Hopkins Ridge Wind Project, Columbia 

County, Washington. Final Report, March 2002 - March 2003. Prepared for RES North 

America, LLC., Portland, Oregon, by Western EcoSystems Technology, Inc.(WEST), 

Cheyenne, Wyoming. April 30, 2003. 

Young, D.P., Jr., W.P. Erickson, R.E. Good, M.D. Strickland, and G.D. Johnson. 2003b. Avian 

and bat mortality associated with the initial phase of the Foote Creek Rim Wind Power 

Project, Carbon County, Wyoming: November 1998–June 2002. Technical report 

prepared by WEST, Inc. for PacifiCorp, Inc., SeaWest Windpower, Inc., and Bureau of 

Land Management. 

Young, Jr., D.P., W.P. Erickson, J.D. Jeffrey, K. Bay, and M. Bourassa. 2003c. Avian and 

Sensitive Species, Baseline Study Plan and Final Report, Eurus Combine Hills Turbine 

Ranch, Umatilla County, Oregon. Technical Report for Eurus Energy America 

114 December 2012 
Mohave County Wind Farm Eagle Conservation Plan and Bird Conservation Strategy 

Corporation and Aeropower Services, Inc. Prepared by: Western EcoSystems 

Technology, Inc., Cheyenne, Wyoming. 

Young, D.P. Jr., J. Jeffrey, W.P. Erickson, K. Bay, and V.K. Poulton. 2006. Eurus Combine Hills 

Turbine Ranch. Phase 1 post construction wildlife monitoring first annual report. 

Technical report prepared for Eurus Energy America Corporation, San Diego, California, 

and the Combine Hills Technical Advisory Committee, Umatilla County, Oregon. 

Prepared by Western EcoSystems Technology, Inc. (WEST), Cheyenne, Wyoming, and 

Northwest Wildlife Consultants, Inc. (NWC), Pendleton, Oregon. 

Young, D.P. Jr., W.P. Erickson, J. Jeffrey, and V.K. Poulton. 2007. Puget Sound Energy 

Hopkins Ridge Wind Project Phase 1 Post-Construction Avian and Bat Monitoring First 

Annual Report, January - December 2006. Technical report for Puget Sound Energy, 

Dayton, Washington and Hopkins Ridge Wind Project Technical Advisory Committee, 

Columbia County, Washington. Western EcoSystems Technology, Inc. (WEST) 

Cheyenne, Wyoming, and Walla Walla, Washington. 25 pp. 

Young, D.P., Jr., C. LeBeau, W. Erickson, S. Nomani, J.R. Boehrs, and B. Oakleaf. 2010. 

Status of breeding populations of ferruginous hawks, golden eagles and bald eagles in 

Albany and Carbon County, Wyoming. Prepared for the Wyoming Game and Fish 

Department (WGFD). 

Zar, J.H. 1996. Biostatistical Analysis, 3rd ed. Prentice Hall, Upper Saddle River, NJ. 

Zuckerman, L. 2012. Mining claim markers killing millions of birds in U.S. West. Reuters. June 

30, 2012. Available at http://articles.chicagotribune.com/2012-06-30/news/sns-rt-us-usabirds-miningbre85t0jj-20120630_1_migratory-birds-pvc-pipes-american-birdconservancy. Accessed on August 21, 2012. 

115 December 2012 
Appendix A

Table of All Avian Species Detected
Appendix A. Table of All Avian Species Detected During Baseline Surveys of the Mohave County Wind Proje

Species Common

Name

Species Scientific

Name

Size

Class1

Resident

Classification2

Total Number Detected USFWS

BCC3

B

Sta

Point Counts Songbird Migration Incidental

Abert's Towhee Pipilo aberti Small Resident - - 1 - 

American kestrel Falco sparverius Large Resident 9 4 168 - 

ash-throated flycatcher Myiarchus cinerascens Small Resident 18 130 25 - 

bank swallow Riparia riparia Small Migrant 2 - - - 

barn owl Tyto alba Large Migrant - - 7 - Bendire's thrasher Toxostoma bendirei Small Resident - - 4 BCC 

black-headed grosbeak Pheucticus melanocephalus Small Resident - 1 - - black-tailed gnatcatcher Polioptila melanura Small Resident 1 12 11 - 

black-throated sparrow Amphispiza bilineata Small Resident 181 428 108 - 

Brewer's sparrow Spizella breweri Small Migrant 2 90 120 - 

brown-headed cowbird Molothrus ater Small Resident - - 7 - 

Bullock's oriole Icterus bullockii Small Resident - - 1 - 

burrowing owl Athene cunicularia Small Resident - - 1 BCC cactus wren Campylorhynchus brunneicapillus Small Resident 26 213 47 - 

Cassin's kingbird Tyrannus vociferans Small Resident 2 - - - 

chipping sparrow Spizella passerina Small Resident 3 4 - - 

chukar Alectoris chukar Large Resident - - 3 - 

cliff swallow Petrochelidon pyrrhonota Small Resident 2 - - - 

common poorwill Phalaenoptilus nuttallii Large Resident - - 4 - 

common raven Corvus corax Large Resident 65 7 55 - common yellowthroat Geothlypis trichas Small Resident - - 1 - 

Cooper's hawk Accipiter cooperii Large Resident - - 2 - 

Costa's hummingbird Calypte costae Small Resident - 4 3 BCC dark-eyed junco Junco hyemalis Small Resident 2 - - - 
Species Common

Name

Species Scientific

Name

Size

Class1

Resident

Classification2

Total Number Detected USFWS

BCC3

B

Sta

Point Counts Songbird Migration Incidental

Gambel's quail Callipepla gambelii Large Resident 28 56 47 - 

gilded flicker Colaptes chrysoides Small Resident 1 - 4 BCC 

golden eagle Aquila chrysaetos Large Resident 5 - 3 - greater roadrunner Geococcyx californianus Large Resident - 4 3 - 

great horned owl Bubo virginianus Large Resident - - 2 - 

horned lark Eremophila alpestris Small Resident 64 2 250 - house finch Carpodacus mexicanus Small Resident 11 44 12 - 

ladder-backedwoodpecker Picoides scalaris Small Resident 1 1 1 - 

lark sparrow Chondestes grammacus Small Migrant - - 3 - 

lark bunting Calamospiza melanocorys Small Migrant - 1 - - 

loggerhead shrike Lanius ludovicianus Small Resident 20 84 45 - 

merlin Falco columbarius Large Migrant 1 - 2 - 

mourning dove Zenaida macroura Large Resident 19 128 36 - 

northern flicker Colaptes auratus Small Resident 3 10 9 - northern harrier Circus cyaneus Large Resident - - 3 - 

northern mockingbird Mimus polyglottos Small Resident 22 109 49 - northern rough-wingedswallow

Stelgidopteryxserripennis Small Resident 2 - - - 

phainopepla Phainopepla nitens Small Resident - - 4 - 

prairie falcon Falco mexicanus Large Resident - - 1 BCC 

red-tailed hawk Buteo jamaicensis Large Resident 23 14 134 - rock wren Salpinctes obsoletus Small Resident 25 61 42 - sage sparrow Amphispiza belli Small Resident 2 2 - - 

sage thrasher Oreoscoptes montanus Small Migrant 27 45 38 - 

savannah sparrow Passerculus sandwichensis Small Migrant - 2 1 - 
Species Common

Name

Species Scientific

Name

Size

Class1

Resident

Classification2

Total Number Detected USFWS

BCC3

B

Sta

Point Counts Songbird Migration Incidental

Say's phoebe Sayornis saya Small Resident 5 - 1 - 

Scott's oriole Icterus parisorum Small Resident 5 40 10 - 

sharp-shinned hawk Accipiter striatus Large Resident 1 - 2 - 

song sparrow Melospiza melodia Small Resident - 1 - - 

tree swallow Tachycineta bicolor Small Resident - - 6 - 

turkey vulture Cathartes aura Large Resident 42 1 58 - vesper sparrow Pooecetes gramineus Small Migrant - - 1 - violet-green swallow Tachycineta thalassina Small Resident - - 2 - 

western kingbird Tyrannus verticalis Small Resident - 5 15 - 

western meadowlark Sturnella neglecta Small Resident 2 - - - western scrub-jay Aphelocoma californica Small Resident 1 - - - 

western wood pewee Contopus sordidulus Small Resident - - 1 - 

white-crowned sparrow Zonotrichia leucophrys Small Resident - 12 84 - 

white-throated swift Aeronautes saxatalis Small Resident 1 - 9 - 

Wilson's warbler Wilsonia pusilla Small Migrant - 1 4 - 

zone-tailed hawk Buteo albonotatus Large Resident - - 1 - 

Total Number of Birds Detected 683 1549 1467 5 

1. Small defined as a bird = 10 inches in length Large defined as a bird > 10 inches in length

2. Migrants defined as species with occurrence in Mohave County restricted to spring and fall migration periods; Residents defined as species with ye

occurrence. Occurrence data used from Peterson Guides Bird Finder List for Mohave County, Arizona

3. USFWS 2008 Birds of Conservation Concern (BCC) for Bird Conservation Region 33 (Sonoran and Mojave Deserts)

4. 2010 BLM Sensitive Species

5. Tiers of Species of Greatest Conservation Need (revised 2010) from the Arizona State Wildlife Action Plan

1A Scored 1 for Vulnerability in at least one of the 9 categories, or is federal endangered, threatened or candidate species; is covered under a sig

is petitioned for listing

1B Scored 1 for Vulnerability but matches none of the additional criteria above

1C Unknown Vulnerability status species

6. Partners in Flight 2004 North American Landbird Conservation Plan Species of Continental Importance

WL2 Watch List Species—Moderately abundant or widespread with declines or high threatsWL3 Watch List Species—Restricted distribution or low population size

AL1 Additional Stewardship Species—High percent of Global Population in single biome (breeding or winter)
Appendix B

Wildlife Incident Reporting System Protocol











Appendix C

Wildlife Incident Reporting Form