Open-File Report 2007-1296

U.S. Department of the Interior

U.S. Geological Survey

National Park Service

In Cooperation with the University of Arizona, School of Natural Resources

Vascular Plant and Vertebrate Inventory of 

Saguaro National Park, Tucson Mountain District
This page left intentionally blank.
 

In cooperation with the University of Arizona, School of Natural Resources 

Vascular Plant and Vertebrate Inventory of 

Saguaro National Park, Tucson Mountain District 

Edited by Brian F. Powell, William L. Halvorson, and Cecilia A. Schmidt 

Open-File Report 2007-1296 

 

U.S. Department of the Interior 

U.S. Geological Survey 

National Park Service

U.S. Geological Survey 

Southwest Biological Science Center 

Sonoran Desert Research Station 

University of Arizona 

School of Natural Resources 

125 Biological Sciences East 

Tucson, Arizona 85721
U.S. Department of the Interior 

DIRK KEMPTHORNE, Secretary 

U.S. Geological Survey

Mark Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

For product and ordering information: 

World Wide Web: http://www.usgs.gov/pubprod

Telephone: 1-888-ASK-USGS 

For more information on the USGS-the Federal source for science about the Earth, its natural and living 

resources, natural hazards, and the environment: 

World Wide Web:http://www.usgs.gov 

Telephone: 1-888-ASK-USGS 

 

 Suggested Citation 

Powell, B.F, Halvorson, W.L., and Schmidt, C.A., eds., 2007, Vascular plant and vertebrate inventory of Saguaro 

National Park, Tucson Mountain District: U.S. Geological Survey Open-File Report 2007-1296, 92 p. 

[http://pubs.usgs.gov/of/2007/1296/].

Cover photo: Saguaro National Park, Tucson Mountain District. Photograph by Don Swann.

Any use of trade, product, or firm names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government. 

 

ii 
Editors and Authors

Brian F. Powell and Cecilia A. Schmidt Aaron D. Flesch 

School of Natural Resources School of Natural Resources 

125 Biological Sciences East, Building 43 325 Biological Sciences East, Building 43 

The University of Arizona The University of Arizona 

Tucson, AZ 85721 Tucson, AZ 85721 

William L. Halvorson Don E. Swann 

USGS SBSC Sonoran Desert Research Station Saguaro National Park 

125 Biological Sciences East, Building 43 3693 South Old Spanish Trail 

The University of Arizona Tucson, AZ 85730 

Tucson, AZ 85721 

U.S. Geological SBSC Survey Sonoran Desert Research Station Personnel 

Charles van Riper III, Station Leader 

William L. Halvorson, Research Ecologist 

Cecil R. Schwalbe, Ecologist 

Michael R. Kunzmann, Ecologist (Emeritus) 

Kathryn Thomas, Ecologist 

Pamela Nagler, Physical Scientist 

Phil Rosen, Ecologist 

Program and Expertise Areas of USGS and UA Personnel

Administration & Outreach 

Laura Opalka 

Wendy Parrish 

Emily Sherbrooke 

Charles van Riper III 

Avian Ecology 

Claire Crow 

Glenn Johnson 

Chris O’Brien 

Brian Powell 

Charles van Riper III 

Data Management 

Brent Sigafus 

Ecology of Amphibians & Reptiles 

Kevin Baker 

Cristina Jones 

Dave Prival 

Phil Rosen 

Cecil Schwalbe 

Brent Sigafus 

Fire Management 

Dennis Suhre 

Cori Dolan 

James Feldmann 

Bill Halvorson 

Invasive Species Research 

Patricia Guertin 

Jim Malusa 

Phil Rosen 

Cecil Schwalbe 

Brent Sigafus 

Dennis Suhre 

Kathryn Thomas 

Inventory & Monitoring 

Patricia Guertin 

Bill Halvorson 

Pamela Nagler 

Brian Powell 

Cecilia Schmidt

Vegetation Mapping & Ecology 

Patricia Guertin 

Bill Halvorson 

Jim Malusa 

Kathryn Thomas 

USGS Southwest Biological Science Center http://sbsc.wr.usgs.gov 

USGS Southwest Biological Science Center, Sonoran Desert Research Station http://sbsc.wr.usgs.gov/sdrs

iii 
iv 
Table of Contents 

Acknowledgments.......................................................................................................................................xi

Executive Summary ...................................................................................................................................xiii

Chapter 1: Introduction to the Inventories....................................................................................................1

Project Overview...................................................................................................................................1

Report Format and Data Organization ..................................................................................................1

Verification and Assessment of Results................................................................................................2

Sampling Design ...................................................................................................................................4

Chapter 2: Park Overview.............................................................................................................................7

Park Area and History...........................................................................................................................7

Natural Resources Overview.................................................................................................................7

Natural Resource Management Issues..................................................................................................9

Chapter 3: Plants.........................................................................................................................................13

Previous Research ...............................................................................................................................13

Methods...............................................................................................................................................13

Results.................................................................................................................................................16

Inventory Completeness......................................................................................................................17

Discussion ...........................................................................................................................................17

Chapter 4: Amphibians and Reptiles ..........................................................................................................21

Previous Research ...............................................................................................................................21

Methods...............................................................................................................................................21

Results.................................................................................................................................................26

Inventory Completeness......................................................................................................................29

Discussion ...........................................................................................................................................33

Chapter 5: Birds..........................................................................................................................................37

Previous Research ...............................................................................................................................37

Methods...............................................................................................................................................37

Results.................................................................................................................................................40

Inventory Completeness......................................................................................................................43

Discussion ...........................................................................................................................................44

Chapter 6: Mammals...................................................................................................................................47

Previous and Ongoing Research .........................................................................................................47

Methods...............................................................................................................................................47

Results.................................................................................................................................................54

Inventory Completeness......................................................................................................................56

Discussion ...........................................................................................................................................58

Chapter 7: Literature Cited .........................................................................................................................61

 

v 
List of Tables

Table 1. Summary of vascular plant and vertebrate inventories at Saguaro National Park, Tucson 

Mountain District, 1999–2005.................................................................................................xiii

Table 1.1. Museums that were queried in 1998 for vertebrate specimen vouchers with “Arizona” and 

“Saguaro National Park” and “Saguaro National Monument” in the collection location. .........3 

Table 2.1. Average monthly climate data for the University of Arizona (low elevation; the closest climate 

monitoring station to the district), 1894–2004. ..........................................................................8 

Table 4.1. Characteristics of three major active survey methods used during surveys for herpetofauna, 

Saguaro NP, Tucson Mountain District, 2001 and 2002. .........................................................21 

Table 4.2. Herpetofauna survey effort by method and year, Saguaro NP, Tucson Mountain District, 2001 

and 2002. ..................................................................................................................................24 

Table 4.3. Number of animals and species detected per hour by method and year, Saguaro NP, Tucson 

Mountain District, 2001 and 2002. ...........................................................................................27 

Table 4.4. Relative abundance (mean and SE; no./ha/hr) of herpetofauna detected during intensive 

surveys along random focal-point transects (n = 5) in spring (11-17 April) and summer (16-24 

July) 2001, Saguaro NP, Tucson Mountain District.................................................................27 

Table 4.5. Relative abundance (mean + SE; no./10 hrs) of amphibians and reptiles detected during 

extensive surveys (n = 55), by topographic formation, Saguaro NP, Tucson Mountain District, 

2001 and 2002. .........................................................................................................................28 

Table 4.6. Relative abundance (no./hr) of amphibians and reptiles detected during road surveys in 

Saguaro NP, Tucson Mountain District, 2001 and 2002. .........................................................30 

Table 4.7. Relative abundance (no./100 hrs) of animals trapped in pitfall trap array (n = 1) in Saguaro 

NP, Tucson Mountain District, 2001 and 2002. .......................................................................30 

Table 5.1. Summary of bird survey effort by UA inventory personnel, Saguaro NP, Tucson Mountain 

District, 2001 and 2002. ..........................................................................................................39 

Table 5.2. Total number of observations (sum) and relative abundance (mean + SE), by transect, of birds 

recorded during repeat-visit VCP surveys, Saguaro NP, Tucson Mountain District, 2001 and 

2002. .......................................................................................................................................41 

Table 5.3. Mean relative abundance of birds from reconnaissance VCP surveys, Saguaro NP, Tucson 

Mountain District, 2002............................................................................................................42 

Table 5.4. Mean relative abundance of birds, by transect, from nocturnal surveys, Saguaro NP, Tucson 

Mountain District, 2001 and 2002. ...........................................................................................43 

Table 5.5. Number of observations for each breeding behavior for birds, Saguaro NP, Tucson Mountain 

District, 2001 and 2002. ..........................................................................................................43 

Table 6.1. Summary of small mammal trapping effort, Saguaro NP, Tucson Mountain District, 2001 and 

2002. .......................................................................................................................................51 

Table 6.2. Summary of infrared-triggered camera effort, Saguaro NP, Tucson Mountain District, 2002-

2005. .......................................................................................................................................54 

Table 6.3. Relative abundance of small mammals trapped at Saguaro NP, Tucson Mountain District, 

2001 and 2002 at random (R) and non-random (NR) trapping grids. ....................................54 

vi 
Table 6.4. Results of roost site detections and netting for bats, Saguaro NP, Tucson Mountain District, 

2001 and 2002. .......................................................................................................................55 

Table 6.5. Number of photographs of mammal species, from infrared-triggered photography, Saguaro 

NP, East, 1999-2005. .............................................................................................................56 

Table 6.6. List of possible bat and rodent species for Saguaro NP, Tucson Mountain District. .............58 

vii 
List of Figures 

Figure 1.1. Layout of 1-km focal-point transects showing layout of amphibian and reptile plots (C), 

small-mammal trapping grids (D), and bird survey stations (E), Saguaro NP, Tucson 

Mountain District.. ....................................................................................................................5 

Figure 2.1. Location of the two districts of Saguaro National Park in southern Arizona. ...........................8 

Figure 2.2. Composite aerial photograph showing major features of Saguaro NP, Tucson Mountain 

District.......................................................................................................................................9 

Figure 2.3. Comparison of monthly weather data during the time of the majority of the inventory effort 

(2001–2003) compared to the mean (1894–2004 for University of Arizona; thick solid line in 

all figures), Tucson Mountain District, Saguaro National Park.. ............................................10 

Figure 3.1. Layout of a modified-Whittaker plot, Saguaro NP, Tucson Mountain District, 2001.............14 

Figure 3.2. Locations of modified-Whittaker plots and point-intercept transects (line transect), Saguaro 

NP, Tucson Mountain District, 2001.......................................................................................15 

Figure 3.3. Typical layout of point-intercept transects, Saguaro NP, Tucson Mountain District, 2001....16 

Figure 3.4. Number of plant species at the five random sites that were found by each of the two field 

methods used at focal points (point-intercept transect and modified-Whitaker plot), Saguaro 

NP, Tucson Mountain District, 2001.......................................................................................17 

Figure 3.5. Vertical vegetation structure (A) and ground cover type (B), by transect, and from pointintercept transects, Saguaro NP, Tucson Mountain District, 2001..........................................18 

Figure 4.1. Typical plot layout of herpetofauna subplots along a 1-km focal-point transect (n = 5), 

Saguaro NP, Tucson Mountain District...................................................................................22 

Figure 4.2. Study site locations for herpetofauna, Saguaro NP, Tucson Mountain District, 2001 and 2002.

.................................................................................................................................................23 

Figure 4.3. Species accumulation curve for herpetofauna surveys, all methods combined, Saguaro NP, 

Tucson Mountain District, 2001 and 2002..............................................................................32 

Figure 4.4. Species accumulation curve for herpetofauna surveys, by survey type, Saguaro NP, Tucson 

Mountain District, 2001 and 2002...........................................................................................33 

Figure 5.1. Location of VCP and nocturnal survey stations for birds, Saguaro NP, Tucson Mountain 

District, 2001 and 2002. ..........................................................................................................38 

Figure 5.2. Species accumulation curve for birds, all survey methods, Saguaro NP, Tucson Mountain 

District, 2001 and 2002.. .........................................................................................................44 

Figure 6.1. Location of random and non-random small-mammal trapping sites, bat trapping stations, and 

Trailmaster cameras (infrared-triggered cameras), Saguaro NP, Tucson Mountain District, 

2001.........................................................................................................................................48 

Figure 6.2. Location of infrared-triggered camera units, Saguaro NP, 2002-2005....................................49 

Figure 6.3. Layout of small-mammal trapping grids along focal-point transects, Saguaro NP, Tucson 

Mountain District, 2001.. ........................................................................................................50 

Figure 6.4. Detailed layout of small-mammal trapping grids at Saguaro NP, Tucson Mountain District, 

2001 and 2002.. .......................................................................................................................50 

viii 
Figure 6.5. Typical configuration for an active infrared-triggered camera system....................................53 

Figure 6.6. Species accumulation curve for small-mammal trapping, Saguaro NP, Tucson Mountain 

District, 2001...........................................................................................................................57 

Figure 6.7. Species accumulation curve for infrared-triggered photography, Saguaro NP, Tucson 

Mountain District, 2002-2005. ................................................................................................57 

ix 
List of Appendices 

Appendix A. List of plant species that were observed (O) or collected (X) at Saguaro NP, Tucson 

Mountain District. ........................................................................................................67 

Appendix B. List of reptiles and amphibians by University of Arizona Inventory personnel and field 

method(s) used to detect them, Saguaro NP, Tucson Mountain District, 

2001 and 2002. ..............................................................................................................78 

Appendix C. List of bird species observed at Saguaro NP, Tucson Mountain District by UA 

inventory personnel (2001 and 2002) or by other survey efforts or lists: Monson 

and Smith (M&S; 1986), Yensen (YE; 1976), Short (SH; 1996), and 

Kline (KL; 1998). ........................................................................................................79 

Appendix D. List of mammals observed at Saguaro NP, Tucson Mountain District by University of 

Arizona (UA) and Saguaro National Park (SNP) Inventory personnel (by survey type, 

2001-2005 and other efforts. .......................................................................................83 

Appendix E. Vertebrate specimen and photograph vouchers collected by University of Arizona or 

park personnel, Saguaro National Park,Tucson Mountain District, 1997–2002. ........85 

Appendix F. List of existing specimen vouchers collected prior to our inventory effort. ................86 

Appendix G. Percent composition (Comp.) and cover from point-intercept transects, by height 

category, Saguaro NP, Tucson Mountain District, 2001. ............................................87 

Appendix H. Presence of plant species at modified-Whitaker vegetation plots, by vegetation 

community and plot number, Saguaro NP, Tucson Mountain District, 2001................90 

Appendix I. Detail of small mammal trapping effort at Saguaro NP, Tucson Mountain District, 2001 

and 2002. .....................................................................................................................92 

Appendix J. Summary of field research for bats, Saguaro NP, Tucson Mountain District, 2001 and 

2002. ............................................................................................................................92 

x 
Acknowledgments 

Thanks to Saguaro National Park Superintendent Sarah Craighead, Chief of Science and Resource 

Management Meg Weesner, and biologists Natasha Kline and Don Swann for providing leadership and 

administrative support for this project. Other park staff who assisted our project included Matt Daniels, 

Mark Holden, and Robert Stinson. This project was funded by the National Park Service (NPS) 

Inventory and Monitoring program (I&M) and was made possible by the collaboration of many people at 

the University of Arizona (UA), NPS, and U.S. Geological Survey (USGS). Administration of the project 

was facilitated by the Desert Southwest and Colorado Plateau Cooperative Ecosystem Studies Units 

(CESUs). The Southern Arizona Office of the NPS assisted with the development of the original study 

plan that led directly to initiation of this project. Additional support (monetary and in-kind) for infraredtriggered photography was provided by the Western National Parks Association, Friends of Saguaro 

National Park, T&E Inc., and the UA Undergraduate Biology Internship Program. 

Andy Hubbard at the Sonoran Desert Network I&M program has been a great advocate of our 

program. He also provided funds for Don Swann to work on this report. Kathy Davis, Superintendent of 

Tuzigoot and Montezuma Castle national monuments played an instrumental role in this project by 

providing important early initiative. Larry Norris at the Desert Southwest CESU has provided strong 

support for our program and spent considerable time and effort providing clear and timely administrative 

assistance. Matt Goode, Don Swann, and Dale Turner provided much of the early planning for this 

project; we are indebted to their vision and work. Eric Albrecht was an outstanding spokesperson and 

leader of the program; he was an invaluable member of the team and his contributions are sorely missed. 

We thank a core group of dedicated field biologists who collected a wealth of data at Saguaro 

National Park: Greta Anderson, Theresa DeKoker, Meg Quinn, Dale Turner, and Emily Willard (plants); 

Dan Bell, Kevin Bonine, James Borgmeyer, Philip Brown, Matt Goode, Dave Prival, and Mike Wall 

(amphibians and reptiles); Eric Albrecht, Gavin Beiber, Chris Kirkpatrick, and Gabe Martinez (birds); 

Eric Albrecht, Melanie Bucci, Matt Caron, Matt Colvin, Tony Dee, Mark Holden, Neil Perry, Jason 

Schmidt, Ronnie Sidner, Patty Stern, Sandy Wolf, and Erin Zylstra (mammals). We are appreciative of 

the following people, many of whom never ventured into the field, but whose work in the office made the 

field effort successful: Debbie Angell, Jennifer Brodsky, Chuck Conrad, Louise Conrad, Brian Cornelius, 

Taylor Edwards, Carianne Funicelli, Marina Hernandez, Colleen McClain, Heather McClaren, Lindsay 

Norpel, Ryan Reese, Jill Rubio, Brent Sigafus, Taffy Sterpka, Jenny Treiber, Zuleika Valdez, Alesha 

Williams, and Erin Zylstra. Pam Anning, Kristen Beaupré, and Matthew Daniels assisted with database 

design. Pam Anning also provided the maps for this report. Additional administrative support was 

provided by Valery Catt, Jenny Ferry, Andy Honaman, Terri Rice, and especially Cecily Westphal of the 

School of Natural Resources at the UA. Special thanks to Lisa Carder and Kathleen Docherty for their 

years of hard work on all aspects of the project. 

Technical support was graciously provided by the following experts: Dan Austin, Michael 

Chamberland, Phil Jenkins, and Charlotte and John Reeder at the UA Herbarium; Tom Huels of the UA 

ornithology collection; George Bradley of the UA herpetology collection; and Yar Petryszyn and Melanie 

Bucci of the UA mammal collection. Thanks to Sharon Megdal and Peter Wierenga, the current and 

former directors, respectively, of the UA Water Resources Research Center, and all their staff. Thanks to 

Mau-Crimmins et al. (2005) and Sprouse et al. (2002) for use of their background information on the 

district and Aaron Flesch (Flesch 2001) for use of some of his discussion in the mammal chapter. We 

received many excellent comments on the amphibian and reptile chapter from Phil Rosen and Cecil 

Schwalbe. Larry Norris, Don Swann, and Meg Quinn reviewed an earlier version of this report. 

xi 
xii 
Executive Summary 

This report summarizes the results of the first 

comprehensive inventory of plants and 

vertebrates at the Tucson Mountain District 

(TMD) of Saguaro National Park, Arizona. 

From 2001 to 2003 we surveyed for vascular 

plants and vertebrates (amphibians, reptiles, 

birds, and mammals) at the district to document 

the presence of species within its boundaries. 

Park staff also carried out extensive infraredtriggered camera work for medium and large 

mammals from 2002-2005 and results from that 

effort are reported here. Our spatial sampling 

design for all taxa employed a combination of 

random and nonrandom survey sites. Survey 

effort was greatest for medium and large 

mammals and herpetofauna. Because we used 

repeatable study designs and standardized field 

methods, these inventories can serve as the first 

step in a biological monitoring program for the 

district. We also provide an overview of 

previous survey efforts in the district. We use 

data from our inventory and other surveys to 

compile species lists and to assess inventory 

completeness. 

The survey effort for herpetofauna, 

birds, and medium and large mammals was the 

most comprehensive ever undertaken in the 

district. We recorded a total of 320 plant and 

vertebrate species, including 21 species not 

previously found in the district (Table 1). Based 

on a review of our inventory and past research at 

the district, there have been a total of 723 

species of plants and vertebrates found there. 

We believe inventories for most taxonomic 

groups are nearly complete. 

Based on our surveys, we believe the 

native plant and vertebrate community 

compositions of the district are relatively intact, 

though some species loss has occurred and 

threats are increasing, particularly to 

herpetofauna and larger mammals. Of particular 

note is the relatively small number of non-native 

species and their low abundance in the district, 

which is in contrast to many nearby natural 

areas. Rapidly expanding development on the 

west, north, and east sides of the district is cause 

for concern that the park continue its 

commitment to environmental restoration, which 

is largely responsible for reducing the threats 

posed by non-native plants. With continued 

maintenance of natural processes and the 

ecological structure of the park’s biodiversity, 

the park will become an increasingly important 

place to both the general public and the 

scientific community. 

This report supersedes results reported 

in Powell et al. (2002, 2003).

 

 

Table 1. Summary of vascular plant and vertebrate inventories at Saguaro National Park, Tucson Mountain District, 

1999–2005. 

UA inventory 

Taxonomic group 

Number of 

species recorded 

Number of new species 

added to district list 

Number of 

non-native species 

Total number of species 

on district list 

Plants 180 8 47 512 

Amphibians and Reptiles 34 0 0 37 

Birds 73 4 2 134 

Mammals 33 9 2 40 

Totals 320 21 50 723 

xiii 
xiv 


Chapter 1: Introduction to the Inventories

Brian F. Powell, Cecilia A. Schmidt, and William L. Halvorson

Project Overview

Inventory: A point-in-time effort to document the 

resources present in an area. 

In the early 1990s, responding to criticism that 

it lacked basic knowledge of natural resources 

within parks, the National Park Service (NPS) 

initiated the Inventory and Monitoring Program 

(I&M) to detect long-term changes in biological 

resources (NPS 1992a). At the time of the 

program’s inception, basic information, including 

lists of plants and animals, was absent or 

incomplete for most park units (Stohlgren et al. 

1995b).

Species inventories have both direct and 

indirect value for management of the park and are 

an important first step in long-term monitoring. 

Species lists are not only useful in resource 

interpretation and facilitating visitor appreciation 

of natural resources, but are also critical for 

making management decisions. Knowledge of 

which species are present, particularly sensitive 

species, and where they occur provides for 

informed planning and decision-making (e.g., 

locating new facilities). Thorough biological 

inventories provide a basis for choosing 

parameters to monitor and can provide baseline 

data for monitoring ecological populations and 

communities. Inventories can also test sampling 

designs, field methods, and data collection 

protocols, and provide estimates of variation that 

are essential in prospective power analysis. 

Goals

The purpose of this study was to complete basic 

inventories for vascular plants and vertebrates 

at the Tucson Mountain District (TMD) of 

Saguaro National Park. This effort was part of a 

larger biological inventory of eight NPS units in 

southern Arizona and southwestern New Mexico 

(Davis and Halvorson 2000; e.g., Powell et al. 

2006a, 2005). Our goals were to: 

(1) Conduct field surveys to document at 

least 90% of all species of vascular plants 

and vertebrates expected to occur at the 

district. 

(2) Use repeatable sampling designs and 

survey methods that allow estimation 

of parameters of interest (e.g., relative 

abundance).

(3) Compile historic occurrence data for all 

species of vascular plants and vertebrates 

from three sources: museum records 

(voucher specimens), previous studies, 

and park records. 

(4) Create resources useful to park managers, 

including detailed species lists, maps 

of study sites, and high-quality digital 

images for use in resource interpretation 

and education. 

 The bulk of our effort addressed the 

first two goals. To maximize efficiency (i.e., the 

number of species recorded by effort) we used 

field methods designed to detect multiple species. 

We did not undertake single-species surveys for 

threatened or endangered species. 

Report Format and Data Organization

Like the report for the Rincon Mountain District 

(Powell et al. 2006b), each taxon-specific chapter 

in this report has separate authorship. As such 

there are some differences in the organization 

and content of each chapter. Appendices related 

to each chapter are attributed to the respective 

author(s). We organized a single literature cited 

chapter at the end of the report. 

In the text, we report both common and 

scientific names for plants, and for vertebrates 

we report only common names (listed in 

phylogenetic sequence) unless we reference a 

species that is not listed later in an appendix; in 

this case, we present both common and scientific 

names. For each taxonomic group we include an 

appendix of all species that we recorded in the 

district (Appendices A–D). In the amphibian and 

reptile and mammal chapters we review species 

that were likely or confirmed to have been present 

historically or that we suspect are currently 

present and may be recorded with additional 

survey effort. Scientific and common names used 

throughout this document are current according 
to accepted authorities for each taxonomic group: 

Integrated Taxonomic Information System (ITIS 

2005) and the PLANTS database (USDA 2005) 

for plants; Stebbins (2003) for amphibians and 

reptiles; American Ornithologists’ Union (AOU 

1998, 2003) for birds; and Baker et al. (2003) for 

mammals. We recognize that the designation of 

a plant as “non-native” using the aforementioned 

lists may lead to the misclassification of some 

species, because these lists indicate only species 

status in North America as a whole, not regions 

within the continent. Therefore, our flora 

underestimates the number of non-native species, 

but because no authoritative list of non-native 

species exists for the region, we believe that use 

of these lists is justified.

Spatial Data

Most spatial data are geographically referenced 

to facilitate mapping of study plots and locations 

of plants or animals. Coordinates were stored 

in the Universal Transverse Mercator (UTM) 

projection (Zone 12), using the North American 

Datum of 1983 (NAD 83). We recorded UTM 

coordinates using hand-held Garmin E-Map®

Global Positioning System (GPS) units (Garmin 

International Incorporated, Olathe, KS; horizontal 

accuracy approximately 10–30 m). We obtained 

some plot or station locations by using more 

accurate Trimble Pathfinder® GPS units (Trimble 

Navigation Limited, Sunnyvale, CA; horizontal 

accuracy about 1 m). Although we mapped the 

locations of study plots, stations, or transects 

on Digital Orthophoto Quarter Quads (DOQQ; 

produced by the USGS), the locations of study 

areas will remain with the park and NPS Sonoran 

Desert Network I&M office in Tucson. We also 

produced distribution maps for all vertebrate 

species from this and other recent survey efforts 

(including wildlife observation cards at the 

park). Those maps will be archived in the same 

locations as the GPS coordinates. 

Species Conservation Designations

We indicate species conservation designations by 

the following agencies: U.S. Fish and Wildlife 

Service (responsible for administering the 

Endangered Species Act), USDA Forest Service, 

Arizona Game and Fish Department, and Partners 

in Flight (a partnership of dozens of federal, 

state and local governments, non-governmental 

organizations, and private industry). 

Databases and Data Archiving

We entered field data into taxon-specific 

databases (Microsoft Access version 97) and 

checked all data for transcription errors. From 

these databases, we reproduced copies of the 

original field datasheets using the “Report” 

function in Access. The output looks similar 

to the original datasheets but data are easier to 

read. The databases, printouts of field data, and 

other data such as digital photographs have been 

distributed to park staff and will be archived at 

Special Collections at the University of Arizona. 

Original copies of all datasheets currently reside 

at the I&M office in Tucson and may be archived 

at another location. Along with the archived data, 

we will include copies of the original datasheets 

and a guide to filling them out. This information, 

in conjunction with the text of this report, should 

enable future researchers to repeat our work. 

Verification and Assessment of Results

Photograph Vouchers

Whenever possible, we documented vertebrate 

species with analog color photographs. Many 

of these photographs show coloration or other 

characteristics of visual appearance in detail, 

and they may serve as educational tools for the 

park staff and visitors. We obtained a close-up 

photograph of each animal “in hand” and, if 

possible, another photograph of the animal in 

natural surroundings. Photographs are archived 

with other data as described above.

Voucher Specimens

Voucher specimens are an indisputable form of 

evidence of a species occurrence. For plants, we 

searched the University of Arizona Herbarium 

for specimens from the district (see Appendix 

A for results), and we collected herbarium 

specimens whenever flowers or fruit were present 

on plants. All specimens that we collected 

were accessioned into the University of Arizona 

Herbarium. To prioritize vertebrate species for 

voucher collection, we first searched the park’s 
specimen collection and that of other universities 

and collections (Table 1.1; see Appendix F 

for results). When we did collect specimens, 

most were found dead. When necessary, we 

euthanized animals according to procedures of 

the University of Arizona’s Institutional Animal 

Care and Use Committee, prepared the specimens 

using UA methods, and deposited them in 

the appropriate collection at the University of 

Arizona. 

Assessing Inventory Completeness

We assessed inventory completeness by (1) 

examining the rate at which new species were 

recorded in successive surveys (i.e., species 

accumulation curves; Hayek and Buzas 1997) 

and (2) comparing the list of species we recorded 

with a list of species likely to be present based 

on previous research and/or expert opinion. 

We created species accumulation curves for 

all taxonomic groups except plants. For all 

accumulation curves (unless indicated otherwise), 

we randomized the order of the sampling periods 

to break up clusters of new detections that 

resulted from temporal conditions (e.g., monsoon 

initiation) independent of cumulative effort. We 

used the computer program Species Richness 

and Diversity III (Pisces Conservation Ltd., IRC 

House, Pennington, Lymington, UK) to calculate 

species accumulation curves where the order 

of samples was shuffled the maximum number 

of times and the average was plotted, thereby 

smoothing the curve.

Estimating Abundance

Estimating population size is a common goal 

of biologists who are motivated by the desire 

to reduce (pest species), increase (endangered 

species), maintain (game species), or monitor 

(indicator species) population size. Our surveys 

at the district were generally focused on detecting 

species rather than estimating population size. 

In many cases, however, we present estimates 

of “relative abundance” by species to provide 

information on areas in which species might be 

more or less common. Relative abundance is 

an index to population size; we calculate it as 

the number of individuals of a species recorded, 

scaled by survey effort. If we completed multiple 

surveys in comparable areas, we included a 

measure of precision (usually standard error) with 

the mean of those survey results. 

Indices of abundance are presumed to 

correlate with true population size, but ecologists 

do not typically attempt to account for variation 

in detectability among different species or 

groups of species under different circumstances. 

Metrics (rather than indices) of abundance do 

consider variation in detection probability, and 

these include density (number of individuals 

per unit area; e.g., one western diamondback 

rattlesnake per km2

) and absolute abundance 

(population size; e.g., 150 western diamondback 

rattlesnakes). These estimates are beyond the 

scope of our research. While it is true that 

indices to abundance have often been criticized 

(and with good reason, c.f. Anderson 2001), the 

Table 1.1. Museums that were queried in 1998 for vertebrate specimen vouchers with “Arizona” and “Saguaro 

National Park” and “Saguaro National Monument” in the collection location. 

Collection Collection cont.

Brigham Young University Oklahoma Museum of Natural History, Norman

Chicago Academy of Sciences Peabody Museum, Yale University

Cincinnati Museum of Natural History & Science Saguaro National Park (collection now at the Western 

Cornell Vertebrate Collections, Cornell University Archaeological and Conservation Center, Tucson)

George Mason University (Fairfax, VA) Strecker Museum, Baylor University, Waco

Illinois Natural History Survey Texas Cooperative Wildlife Collection

Marjorie Barrick Museum, University of Nevada-Las Vegas Tulane Museum of Natural History

Michigan State University Museum (East Lansing) University of Arizona

Milwaukee Public Museum University of Texas, Arlington 

Museum of Natural History, University of Kansas University of Illinois, Champaign-Urbana

Museum of Texas Tech University University of Colorado Museum

Museum of Vertebrate Zoology, University of California, Berkeley United States National Museum

Museum of Life Sciences, Louisiana State University, Shreveport Walnut Canyon National Monument

Natural History Museum of Los Angeles County Western Archaeological and Conservation Center, Tucson

North Carolina State Museum of Natural Sciences Wupatki National Monument
abundance information that we present in this 

report is used to characterize the commonness 

of different species rather than to quantify 

changes in abundance over long periods of time 

(e.g., monitoring). As such, relative abundance 

estimates are more useful than detectabilityadjusted estimates of density or abundance for 

only a few species or raw count data for all 

species without scaling counts by survey effort. 

Sampling Design

Overview

Sampling design is the process of selecting 

sample units from a population or area of interest. 

Unbiased random samples allow inference to 

the larger population from which those samples 

were drawn and enable one to estimate the true 

value of a parameter. The precision of these 

estimates, based on sample variance, increases 

with the number of samples taken; theoretically, 

random samples can be taken until all possible 

samples have been selected and precision is exact 

– a census has been taken and the true value is 

known. Non-random samples are less likely to be 

representative of the entire population, because 

the sample may (intentionally or not) be biased 

toward a particular characteristic, perhaps one of 

interest or convenience. 

In our surveys we employed both random 

and non-random spatial sampling designs for 

all taxa. For random sites, we co-located all 

taxonomic studies at the same sites (focal points 

and focal-point transects; see below for more 

information) because some characteristics, 

especially vegetation, could be used to explain 

differences in species richness or relative 

abundance among transects. We also used 

vegetation floristics and structure to group 

transects into community types that allowed more 

accurate data summaries. The location of nonrandom study sites was entirely at the discretion 

of each field crew (i.e., plants, birds, etc.) and we 

made no effort to co-locate them. 

Focal Points and Focal-point Transects: Random 

Sampling 

We chose a simple random design to assign 

the location of our focal points. This was in 

contrast to the stratified random design that we 

used at the Rincon Mountain District, which 

had numerous environmental communities that 

corresponded to elevational gradients (Powell 

et al. 2006b). At the Tucson Mountain District 

we used the following process to assign the 

location of random study areas. First, we created 

50 random (hereafter referred to as “focal”) 

points using the Animal Movement extension 

for ArcView (developed by the USGS Alaska 

Science Center – Biological Science Office), 

using uniform distribution, allowing zero meters 

to the district boundary, and zero meters between 

points. For each focal point, we generated a 

random bearing (the numbers ranged from 0 to 

359). We then used the Bearing and Distance 

extension for ArcView (developed by Ying Ming 

Zhou, March 29, 2000; downloaded from ESRI 

ArcScripts website) to create points based on the 

distance and bearing from the original points. 

This gave us start points and end points for all 

50 focal points. We then used the “from” and 

“to” coordinates to draw the transect line using 

an Avenue script (“Draw line by coordinates,” 

developed by Rodrigo Nobrega, August 13, 1998; 

downloaded from ESRI ArcScripts website). The 

result was randomly placed, 1000-m line transects 

(hereafter referred to as “focal-point transects” 

or “transects”). Focal-point transects were not 

allowed to overlap. If this occurred, an entire 

new selection was conducted until a scenario of 

no overlapping transects was achieved.

Many focal-point transects were not used 

because either some part of them lay outside of 

the district boundary or they were in areas where 

the terrain was too steep to work safely (i.e., 

crossed areas with slopes exceeding 35 degrees). 

These “danger” areas were derived from 30- 

m Digital Elevation Models using the Spatial 

Analyst extension for ArcView. The final design 

produced four bird-survey stations spaced 250- 

m apart; 10, 100 x 100-m amphibian and reptile 

plots; and 20, 50 x 50-m mammal plots along the 

focal-point transect line (Fig. 1.1). We sampled 

vegetation by point intercept along six, 50-m 

transects (see Chapter 3 for more information).

To map the location of plots, we designed 

a footprint of the sampling grids using an 

Avenue Script (“View.CreateTransectLines,” by 
Neal Banerjee, October 5, 2000; downloaded 

from ESRI ArcScripts website) to create grid 

lines every 100 m that were perpendicular (90 

degrees) to a “dummy” transect (Fig. 1.1A). 

These grid lines were converted from graphics to 

shapes using the XTools extension for ArcView 

(developed by the Oregon Department of 

Forestry). We then generated points where each 

grid line intersected the transect using the Themes 

Intersections to Points extension for ArcView 

(developed by Arun Saraf, November 11, 1999; 

downloaded from ESRI ArcScripts website) (Fig. 

1.1B). 

We created 100 x 100-m squares 

centered on each intersection point to generate 

the amphibian and reptile plots using the 

Square Buffer Wizard extension for ArcView 

(developed by Robert J. Scheitlin, May 12, 2000; 

downloaded from ESRI ArcScripts website). 

These squares were numbered 1 to 10 in the 

direction of the transect bearing (Fig. 1.1C). The 

same process was repeated to create the mammal 

plots (Fig. 1.1D). Four bird survey stations were 

created by selecting the center of mammal plots 

3, 8, 13, and 18 and buffering each of these points 

with a radius of 125 m (Fig. 1.1E). These circles 

were numbered 1 to 4 in the direction of the 

transect bearing.

Non-random Selection of Study Sites

Many areas of the district contain unique areas 

requiring special surveys for all taxa. Cliffs, 

rocky outcrops, and ephemeral pools were 

likely to be missed if we located our study sites 

only in random areas. These areas are diversity 

“hotspots” and are therefore crucial to visit 

in order to complete the species inventories. 

We selected these study areas based on our 

knowledge of the district. 

Figure 1.1. Layout of 1-km focal-point transects showing layout of amphibian and reptile plots (C), smallmammal trapping grids (D), and bird survey stations (E), Saguaro NP, Tucson Mountain District. Figures A and B 

represent the building blocks of the other transects. 

00m

 1 2 3 4 5 6 7 8 9 10

 2 3 4 5 6 7 8 9 0  2 3 4 5 6 7 8 9 20 

1 2 3 4

A

B

E

D

C



Park Area and History

Saguaro National Park is located in eastern Pima 

County adjacent to Tucson, Arizona (Fig. 2.1). 

Originally designated as a national monument, 

the park was created in 1933 to preserve the 

“exceptional growth” of the saguaro cactus (NPS 

1992b). In 1961, the park was expanded to 

include over 9,000 ha of the Tucson Mountains 

(known as the Tucson Mountain District) and was 

expanded again by legislation in 1976 and 1994. 

The Tucson Mountain District is the subject of 

this report (see Powell et al. 2006b for the Rincon 

Mountain District report). The Tucson Mountain 

District consists of 9,727 ha and is bounded by 

private and state land to the north, east, and west 

and by Pima County’s Tucson Mountain Park and 

private land to the south. Although created to 

preserve natural resources, the park is also home 

to Native American campsites and petroglyphs 

and contains remnants of early ranching and 

mining (NPS 1992b). Annual visitation to both 

districts of the park averages approximately 

700,000 (NPS 2005).

Physiography, Geology, and Soils

Saguaro National Park is located within the 

Basin and Range Physiographic Province. 

The district encompasses much of the Tucson 

Mountains. These mountains were created 

through uplifted, tilted and faulted intrusives, 

volcanics and sediments. Topography at Tucson 

Mountain District ranges from desert flats 

to rocky outcroppings. Elevation at Tucson 

Mountain District ranges from 670 m on the west 

side of the district to 1429 m at Wasson Peak. 

There are many rock types found in Tucson 

Mountain District including limestone, rhyolite, 

sandstone, and granite. The Tucson Mountains 

are predominated by rhyolite, laid down during a 

period of volcanism about 70 million years ago 

(Scarborough 2000).

The Tucson Mountain District is 

characterized by a rugged, boulder-strewn terrain 

that is cut from many steep-channeled washes 

that run only ephemerally. Below the foothills, 

these washes fan out into larger multi-channeled 

bodies. The district contains no natural sources 

of perennial water; however there are several 

drainages, such as King Canyon and Javelina 

and Panther Peak washes that often flow during 

periods of heavy rainfall.

Natural Resources Overview

Climate

Saguaro National Park experiences an annual 

bimodal pattern of precipitation that is 

characterized by heavy summer (monsoon) 

storms brought about by moisture coming from 

the Gulf of Mexico, and less intense frontal 

systems coming from the Pacific Ocean in the 

winter. On average, approximately one-half of 

the annual precipitation falls from July through 

September (Table 2.1; WRCC 2005). The area’s 

hot season occurs from April through October; 

daily maximum temperatures exceed 40o

C. 

Winter temperatures can dip below freezing and 

snow occurs, but is uncommon, on Wasson Peak. 

From 2001 to 2003, during the time of 

most of our inventory effort, average annual 

precipitation totals ranged from slightly to 

substantially below the long-term mean of 28.6 

cm (21.7 cm in 2001, 19.0 cm in 2002 and 26.5 

cm in 2003; Fig. 2.3; WRCC 2005). Average 

annual temperatures from 2001 to 2003 were 

above the long-term mean of 21.3o

C (21.5oC in 

2001, 21.6o

C in 2002 and 22.0oC in 2003; Fig 2.3; 

WRCC 2005). 

Vegetation

Sonoran desertscrub is the dominant vegetation 

community in the district and is found throughout 

the district except at the highest points near 

Wasson Peak, where there is representation of 

semi-desert grasslands. According to Rondeau et 

al. (1996), the district has seven plant associations 

based on Brown and Lowe (1980) classification: 

Creosote Bush Association, Creosote Bush–

Bursage Association, Palo Verde–Saguaro–

Ironwood Association, Palo Verde–Saguaro 

Association, Jojoba Mixed–Scrub Association, 

Desert Grassland and Desert Riparian Scrub. 

Chapter 2: Park Overview

Brian F. Powell, Cecilia A. Schmidt, and William L. Halvorson
Figure 2.1. Location of the two districts of Saguaro National Park in southern Arizona.

Table 2.1. Average monthly climate data for the University of Arizona (low elevation; the closest climate monitoring 

station to the district), 1894–2004. Data from WRCC (2005).

Month

Characteristic Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

Maximum temperature (o

C) 18.6 20.5 23.5 27.8 32.6 37.7 37.8 36.7 35.1 29.9 23.5 19.0 28.6

Minimum temperature (o

C) 3.1 4.5 6.7 9.9 14.2 19.3 23.3 22.4 19.3 12.7 6.6 3.4 12.1

Precipitation (cm) 2.3 2.2 1.9 1.0 0.4 0.7 5.2 5.4 3.0 1.9 2.0 2.5 2.3
The dominant trees and shrubs in the district 

are triangle-leaf bursage (Ambrosia deltoidea), 

palo verde (Cercidium spp.), Ironwood (Olneya 

tesota), acacia (Acacia spp.), and creosote bush 

(Larrea tridentata). Succulents are ubiquitous 

and include: saguaro (Carnegia gigantea), agave 

(Agave spp.), yucca (Yucca spp.), barrel cactus 

(Ferocactus), pincushion cactus (Mammillaria

spp.), and prickly pear and cholla (Opuntia spp.). 

Warm- and cool-season annuals, both native 

(e.g., woolly plantain; Plantago patagonica ) and 

introduced (e.g., red brome; Bromus rubens) are 

common following rainfall.

Natural Resource Management Issues

Adjacent Land Development

Increasing housing development along the east 

and west boundaries of the district has become 

the most pressing natural resource issue. Located 

between both districts of the park, the greater 

Tucson metropolitan area is one of the fastest 

growing in the United States (PAG 2005). The 

area currently has an estimated population 

of 800,000, a 44% increase over the last two 

decades. The increase in human residents brings 

with it a variety of natural-resource-related 

problems including harassment and predation of 

native species by feral animals, increased traffic 

leading to altered animal movement patterns and 

mortality, the spread of non-native species, illegal 

collections of animals, vandalism, increased 

water demands, air pollution from vehicle 

emissions, and visual intrusions to the natural 

landscape (Briggs et al. 1996). Throughout this 

document we highlight some of these impacts as 

they pertain to each taxonomic group. 

Non-native Species and Changes to Vegetation

The spread of non-native species within the 

district is an important natural resource issue. 

Figure 2.2. Composite aerial photograph showing major features of Saguaro NP, Tucson Mountain District. 
10

In particular buffelgrass, Lehmann lovegrass, 

red brome, and other non-native grasses have 

increased in the last ten years (Funicelli et 

al. 2001). The spread of some non-native 

plants used for landscaping, such as crimson 

fountaingrass from development bordering the 

district is also a concern, especially along washes. 

The invasion of non-native grasses has led to 

structural changes in vegetation, from areas that 

supported mostly sparse bunchgrasses to areas 

of fairly uniform grass cover. This change in 

species composition and structure can alter the 

fire regime of the area by supporting higher fire 

frequencies, thereby leading to other changes in 

vegetation composition and structure (Burgess 

et al. 1991, Anable et al. 1992). Nowhere are 

these effects more evident than in the Sonoran 

desertscrub vegetation community, which rarely 

burned historically (Steenbergh and Lowe 1977). 

Many native plant species, especially succulents, 

are not adapted to short duration but highintensity fires and therefore die (Schwalbe et al. 

1999, Dimmitt 2000). Fires such as the Mother’s 

Day Fire (Rincon Mountain District), fueled 

largely by non-native grasses, have caused a high 

mortality of saguaro cactus (Schwalbe et al. 1999; 

see Chapter 3 for additional information). 

Month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Centimenters from mean -4

-2

0

2

4 2001

2002

2003

Precipitation

Month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Degrees Celsius difference from mean

-4

-2

0

2

4

6

2001

2002

2003

Temperature

Figure 2.3. Comparison of monthly weather data during the time of the majority of the inventory effort (2001–2003) 

compared to the mean (1894–2004 for University of Arizona; thick solid line in all figures), Tucson Mountain District, 

Saguaro National Park. Data from WRCC (2005). Degrees Celsius difference from mean Centimeters from mean
11

Abandoned Mines

The Tucson Mountain District has numerous 

seeps and pools located inside mines, which 

can be a source for water contamination. In 

particular, soil samples from the Old Yuma Mine 

identified high contaminant levels for arsenic, 

copper, zinc, and lead. These contaminants could 

easily enter local water supplies as a result of 

heavy rainfall and subsequent runoff (Mott 1997). 

Other mines in the district, such as Gould Mine 

and Mile Wide Mine, have tailings which could 

leach contaminants into residential water sources. 

Not all abandoned mines pose an environmental 

hazard and risk to public health. Old Yuma and 

Gould mines are important roosting sites for bats 

(see Chapter 6).
12
13

Previous Research

Among the earliest botanical information for 

the district is a list of 430 species, compiled by 

Ranger-Naturalist Richard Wadleigh, known or 

suspected to occur in the district (1969). The 

list was a good start for compiling information 

on the flora of the district, but was not based on 

collections. The best flora for the district was by 

Van Devender (1992) and Rondeau et al. (1996), 

who produced a comprehensive inventory of the 

district and other areas of the Tucson Mountains. 

They included extensive information on the 

distribution, abundance, elevation range, and 

flowering phenology of the species that they 

found during field research from 1987 to 1993. 

This remains the most comprehensive synthesis 

of information on the plants of the district and 

we refer the reader to their work for an annotated 

species list and discussions of biogeography. 

They also provide an excellent overview of 

previous research and collecting from the range 

and comparisons to other floras of the region. 

Our work was intended to revise their species list 

for the district and to provide supporting data for 

the vertebrate inventories. 

In 1990 the park established 20 plots to 

document injury to saguaro cactus and to map the 

distribution of other plants. Park personnel used 

these plots to establish 20 long-term vegetation 

transects in low-elevation areas of the district and 

used the point-intercept method in multiple years 

and seasons from 1998 to 2005 (Holden 2005). 

To our knowledge, no comprehensive species 

list was produced from that effort. In 2002, park 

personnel established an additional four transects 

on recently acquired lands. Funicelli et al. 

(2001) resurveyed the original 20 plots, which 

were also used by Turner and Funicelli (2000) to 

resurvey the condition and population structure 

of saguaro cacti. The saguaro cactus, the park’s 

namesake, has been one of the most investigated 

non-agricultural plants in the world. McAuliffe 

(1993) provides an excellent overview of saguaro 

research at the park. Halvorson and Guertin 

(2003) mapped locations of 5 species of nonnative plants, and Bertelsen (1998) completed 

inventories of two pieces of land that had been 

added to the district in 1994. May (1970) 

produced the first vegetation-type map for the 

district, and there are plans to update the map 

(Andy Hubbard, pers. comm.).

We located specimens representing 362 

species at the University of Arizona Herbarium, 

many of which were collected by Rondeau et al. 

(1996). Because of its close proximity to Tucson, 

and the 1904 establishment of the Carnegie 

Desert Botanical Laboratory on Tumamoc Hill, 

there has been considerable collecting in the 

Tucson Mountains. See Rondeau et al. (1996) for 

an excellent summary of collecting in the range. 

 

Methods

We used three methods to survey for plants: 

(1) general botanizing surveys that involved 

opportunistically collecting species that we 

thought might be new to the district list or that 

we could not identify in the field, (2) modified 

Whittaker plots, and (3) line transects at all 

focal-point transects (FPT) to make quantitative 

comparisons among areas, provide data for longterm monitoring, and provide supporting data for 

the vertebrate inventories. 

General Botanizing

Methods

Whenever possible we collected at least one 

representative specimen (with reproductive 

structures) for each plant species that we 

encountered. We also maintained a list of species 

observed but not collected. When we collected a 

specimen, we assigned it a collection number and 

recorded the flower color, associated dominant 

vegetation, date, collector name(s), and UTM 

coordinates. We pressed and processed the 

specimens on site. Specimens remained pressed 

for two to three weeks and were later frozen 

for 48 hours or more to prevent infestation by 

insects and pathogens. Mounted specimens 

were accessioned into the University of Arizona 

Herbarium.

Chapter 3: Plants

Brian F. Powell and Cecilia A. Schmidt
14

Effort

We collected specimens during 10 days of 

fieldwork from 12 April to 10 October 2001. 

Analysis

We present a variety of summary statistics: total 

number of species found and number and percent 

of native and non-native species. 

Modified-Whittaker Plots

Methods

We used modified-Whittaker plots to characterize 

the plant community at a single area associated 

with focal points. Each plot was 20 x 50 m (1000 

m2) and contained 13 subplots of three different 

sizes (see Stohlgren et al. 1995a): 0.5 x 2 m (10 

subplots), 2 x 5 m (2 subplots), and 5 x 20 m (1 

subplot) (Fig. 3.1; Shmida 1984). We estimated 

the cover (m2

) of each plant species for the entire 

1000 m2 plot. For all subplots we simply noted 

the presence of each species. For a more detailed 

explanation of the data collection method, see 

Shmida (1984). For safety reasons, we deviated 

from the methods outlined in Shmida (1984) by 

not surveying against the contours in steep areas.

Effort

We used modified-Whittaker plots at 5 focal 

points (Fig. 3.2). We used a single observer 

(Patty West) to estimate percent cover in the 20 

x 50 m plot, but other observers occasionally 

assisted with noting presence of plants in 

subplots. 

Analysis

In this report we indicate the presence of each 

species over the entire plot. We also note patterns 

of species richness among plots. We do not give 

as complete a summary of the data as for pointintercept transects because the latter method is 

more repeatable and less subjective. However, 

we have provided more complete summary data 

for modified-Whitaker plots to the park and the 

raw data will be available through the park and 

network. 

Point-intercept Transects

Methods

We used the point-intercept method (Bonham 

1989) to sample vegetation along 50-m transects 

located along each focal-point transect (Fig. 

0.5 x 2m 

2 x 5m 

5 x 20m 

20m

50 m 

Figure 3.1. Layout of a modified-Whittaker plot, Saguaro NP, Tucson Mountain District, 2001.
15

3.3). Point-intercept transects began at 25, 125, 

425, 525, 825 and 925 m from the beginning of 

the transect (i.e., focal point). For example, the 

first transect started at 25 m from the focal point 

and went to the 75-m mark. We placed a 50-m 

transect tape along the length of each transect 

section. In each of four height categories (<0.5 

m, 0.5–2 m, 2-4 m, and >4 m) we recorded the 

species of the first plant intercepted by a vertical 

line every 1 m along the transect line (n = 300 

points for most transects). We created the vertical 

line using a graduated pole and extrapolated 

contacts in a fourth height category (>4 m), which 

was rarely used. We classified groundcover as 

rock, bare ground, annual forb, grass, or woody 

debris.

Effort

We surveyed along each of the five random 

transects in the spring of 2001. We typically 

worked in groups of two or three field personnel, 

but sometimes had as many as five field 

Figure 3.2. Locations of modified-Whittaker plots and point-intercept transects (line transect), Saguaro NP, 

Tucson Mountain District, 2001.
16

personnel. We surveyed a total of 300 points 

along most transects, but we surveyed 1000 

points along transect number 204 to test the 

feasibility of completing that many points. 

Analysis

We calculated percent cover and percent 

composition for each species in each height 

category. Percent cover is the number of times a 

species was encountered along the entire length 

of the transect divided by effort (in most cases a 

maximum of 300 intercepts per height category) 

and multiplied by 100. We calculated percent 

composition of each species in each height 

category as the number of times a species was 

encountered divided by the number of times all 

other species were encountered. If there was 

at least a single species encountered along a 

transect (in a height category), the total percent 

composition equaled 100 percent. 

Results

We found 180 species during our inventory 

effort (Appendix A). Of these, we observed 

or collected at least 8 but as many as 28 new 

species for the district, including 7 non-native 

species. (In all we confirmed eight new species 

for the district, with 20 new species possible but 

unsubstantiated because of a lack of a specimen.) 

Many of the new species for the district (n = 

22) were from our point-intercept transects and 

modified-Whitaker plots, though most of these 

new species were observations and not based on 

voucher specimens. Based on a review of current 

and past research efforts, there have been a total 

of 512 species documented for the district, of 

which 9.1% (n = 47) are non-native. 

Distance from focal point 

25 m 

(A)

125 m 

Focal point (beginning 

of transect) Point-intercept transects 

925 m 825 m 525 m 425 m 

50 m

0 m 

General Botanizing and Specimen Collection

We collected 89 specimens representing 74 

species during general botanizing surveys 

(Appendix A). We collected specimens from 33 

sites. We found two new species of plants for 

the district while conducting general botanizing 

surveys. 

Focal Points-General Patterns

We found 176 species on point-intercept transects 

and modified-Whitaker plots. The mean number 

of species per site was 80 (+ 10.1 [SD]). The 

range was 61 species (Point 213) to 116 species 

(Point 204). Of the 176 total species, we found 

14 species at all five sites and 95 species at only a 

single site (Appendices G, H). 

Point-intercept Transects

We found 83 species along all five point-intercept 

transects (Appendix G). The mean number 

of species at each transect was 31 (+ 7.5) and 

ranged from 14 to 57 (Fig. 3.4). Based on the 

presence of vegetation in each of the four height 

categories, there were some differences in 

vegetation structure among transects (Fig. 3.5). 

However, all transects exhibited the same pattern 

and were approximately what we expected: more 

vegetation close to the ground and progressively 

less vegetation in successive height categories. 

Percent ground cover by type was variable among 

transects (Fig. 3.5). 

Modified-Whitaker Plots

We recorded 151 species on modified-Whitaker 

plots. The mean number of species per plot 

Figure 3.3. Typical layout of point-intercept transects, Saguaro NP, Tucson Mountain District, 2001. 
17

was 65 + 7.3 with the range from 45 to 89. We 

observed 73 species on a single plot and 10 

species on all five plots (Appendix G). Yellow 

palo verde (Parkinsonia microphylla) was found 

on all plots and was among the most common 

species. 

Modified-Whitaker vs. Point-intercept Transects

Comparing both Modified-Whitaker plots and 

point-intercept transects, we found a mean of 

43% (+ 8.1) more species on Modified-Whitaker 

plots (Fig. 3.4). The percentage of the total 

number of species observed on both plots and 

transects for each site was only 18 (+ 3.1). 

Inventory Completeness

The Tucson Mountains have a long tradition of 

botanical studies and collecting, starting with the 

establishment of the Carnegie Desert Botanical 

Laboratory (now called the Desert Laboratory) 

on the east edge of the Tucson Mountains in the 

beginning of the 20th century. Though not a part 

of the park, the Desert Laboratory is one of the 

longest-running ecological research sites in the 

world and, as a result, has produced important 

research that has applicability to the district (e.g. 

Goldberg and Turner 1986). As a result of these 

and other research and collecting efforts, both 

outside and inside the district’s boundaries, the 

Tucson Mountains have one of the best regional 

floras in the southwest. Yet we found evidence 

that the flora for the district is not complete. In 

particular, we found at least eight new species 

of plants (and as many as 28) for the district 

with minimal survey effort. We found most 

of these species away from trails (the typical 

location for collections) and associated with focal 

points. Therefore, it is difficult to determine if 

ours and other surveys have reached the goal of 

documenting 90%. 

Discussion

The Tucson Mountain District has a 

representative flora of the Tucson Mountains 

with some special elements. This dry mountain 

range contains very few sources of perennial 

water, but still maintains a surprisingly high plant 

species richness when compared to other areas 

with similar features (Rondeau et al. 1996). This 

richness is due to geographic location, elevation 

range, climate, and differences in soil types. 

The Tucson Mountains have mild winters 

and infrequent frost, allowing many frostsensitive species to thrive (Rondeau et al. 1996). 

Transect number

204 212 213 238 239

Number of species

0

20

40

60

80

100

120

140

Whitaker only 

Transect only 

Common to both 

Figure 3.4. Number of plant species at the five random sites that were found by each of 

the two field methods used at focal points (point-intercept transect and modified-Whitaker 

plot), Saguaro NP, Tucson Mountain District, 2001. 
18

These species, such as desert ironwood (Olneya 

tesota), are absent from the cooler Rincon 

Mountain District. The Tucson Mountains are 

also noted for being at a transition zone among 

a number of phytogeographic provinces, with 

floristic influences from the Mojave, Chihuahuan, 

and Great Basin deserts (McLaughlin and Bowers 

1999). 

The area on and around Wasson Peak is 

a notable site within the Tucson Mountains in 

general, and the district in particular. In this 

highest-elevation site of the range is a remnant 

patch of semi-desert grassland, which is 

responsible for many plants with distributions 

that are largely restricted to that community 

including black, hairy, and sideoats grama 

(Bouteloua spp.), plains lovegrass (Eragrostis 

intermedia), curly mesquite grass (Hilaria 

belangeri), and shin dagger (Agave schottii). 

Also on Wasson Peak are relicts of the chaparral 

community, species such as Arizona rosewood 

(Vauquelinia californica) and banana yucca 

(Yucca baccata). This area is very much at an 

ecotone and will likely be subsumed, in the 

coming decades, by the lower-elevation desert 

scrub vegetation community as a result of global 

Transect number

204 212 213 238 239

Percent of individuals in height catagory

0

10

20

30

40

50

60

0-0.5 m

0.5-2 m 

2-4 m

> 4 m

Transect number

204 212 213 238 239

Percent

0

20

40

60

80

Plant

Rock or bare ground

Other

A

B

Figure 3.5. Vertical vegetation structure (A) and ground cover type (B), by transect, and from pointintercept transects, Saguaro NP, Tucson Mountain District, 2001. Zero values for ground cover for 

transect 204 are because we did not record ground cover at that transect. Percent of individuals in height category Percent
19

climate change (Allen and Breshears 1998). 

Therefore, we anticipate a declining trend in the 

richness and abundance of grassland-associated 

species on and around Wasson Peak. Evidence 

of an increase in woody plant cover throughout 

the district (Funicelli et al. 2001) is further proof 

that encroachment of woody plants into the semidesert grasslands may be happening at a rapid 

pace. 

The current distribution and abundance of 

non-native plant species appear to occur in >2% 

of the land area of the district (Holden 2005; 

Funicelli et al. 2001), yet the number of nonnative species is increasing. The percentage 

of non-native species on long-term monitoring 

transects in the district increased from 2.5% in 

2001 to 10.5% in 2005 (Holden 2005), though 

it is unclear if this increase is biologically 

significant or an artifact of sampling error or 

seasonal conditions. Despite the lack of clear 

evidence for recent trends in the distribution 

of non-native species, the general trend is for 

non-native species to remain at low abundance, 

then increase rapidly in the span of a few years 

because conditions are favorable. For example, 

the distribution and abundance of buffelgrass 

(Pennisetum ciliare) at the Desert Laboratory 

was restricted to a few isolated populations in 

the early 1990s but has since spread to large and 

contiguous patches throughout the area (Desert 

Laboratory, unpublished data). 

Non-native plants are an important 

management concern because they alter 

ecosystem function and processes (Naeem 

et al. 1996, D’Antonio and Vitousek 1992), 

reduce abundance of native species, and cause 

potentially permanent changes in diversity 

and species composition (Bock et al. 1986, 

D’Antonio and Vitousek 1992). However, 

some species have stronger impacts on the 

ecological community than others. In assessing 

the potential threat posed by non-native species, 

it is important to consider the spatial extent of 

species, particularly those species that have 

been identified as “invasive” or of management 

concern. The most widespread and potentially 

disruptive non-native species in the district 

are the perennials buffelgrass and crimson 

fountain grass (Pennisetum setaceum) and the 

annuals red brome (Bromus rubens), redstem 

fillaree (Erodium cicutarium), barley (Hordeum 

murinum), and London rocket (Sisymbrium 

irio). The park has had a successful eradication 

program for targeted buffelgrass and fountain 

grass, in particular. This control program has been 

extremely successful at preventing widespread 

establishment of the many problem species. 

Given this success continued non-native plant 

control seems warranted. Another species that 

has not yet been recorded at the district is Sahara 

mustard (Brassica tournefortii). This species 

will likely become established on the west side 

of the monument in sandy substrates. In years 

of substantial winter rains it may dominate some 

sites. 

Additional Research and Monitoring Needed

We suggest that additional surveys are needed to 

complete the species list for the district and that 

surveys should take place throughout the district, 

particularly off trails, especially to relocate and 

collect vouchers for the 20 species that were 

only observed in 2001. However, because of the 

increased number and distribution of non-native 

and invasive species in the region and concern 

for their impacts on natural areas, we suggest 

that surveys adjacent to development and along 

roads are most likely to ensure early detection of 

potentially invasive species. We also suggest that 

surveys should take place after good monsoon 

and winter rains to ensure collection of annuals. 

Vegetation monitoring will be an important 

component of the I&M program at Saguaro 

National Park and other park units in the Sonoran 

Desert Network (Mau-Crimmins et al. 2005), yet 

field methods and communities for vegetation 

monitoring have not yet been established. Our 

use of the modified-Whittaker plots and pointintercept transects provides data to inform that 

program. If the goal of the I&M program is to 

monitor species richness or species composition, 

the modified-Whittaker plots may be more 

appropriate than the point-intercept method 

because of the higher species richness observed 

on the modified-Whittaker plots. However, 

observer bias in estimating species cover is 

the most important limitation of the modifiedWhittaker and similar methods for monitoring 
20

that parameter. In fact, variation in estimates 

of cover can be so great as to obscure trend 

detection for all but the most extreme changes 

(Kennedy and Addison 1987). Bias can be 

minimized by reducing the size of the quadrat 

(Elzinga et al. 2001). With regards to observer 

bias, the point-intercept (or similar line-intercept) 

transects produced less biased estimates of 

species cover because there was less opportunity 

for interpretation. Elzinga et al. (2001) provide 

an excellent overview of the major survey 

methods for monitoring plants, including a good 

discussion of observer bias issues. 

If the goal of the monitoring program is 

to monitor changes in vegetation structure and 

gross vegetation characteristics (i.e., dominant 

plant species), then the point-intercept method 

is likely the more appropriate of the two 

methods. Because transects are spaced over a 

1-km transect, estimates of cover are likely to 

be more representative of the study area than a 

single 20 m x 50 m plot. Further, accuracy of 

cover estimates from point-intercept transects 

and quantification of the vegetation heterogeneity 

can be assessed by using estimates from each 

50-m transect section. Estimates of accuracy and 

heterogeneity for modified-Whitaker plots can 

also be accomplished by establishing multiple 

plots. 

Powell et al. (2005) and others (I&M 

program, unpublished data) used similar field 

methods as reported here and found many of the 

same patterns with regard to species richness and 

cover estimates. Their use of “modular” plots 

(where point-intercept transects were established 

within Braun-Blanquet plots [similar to modifiedWhitaker plots; Braun-Blanquet 1965]) will 

provide a more rigorous comparison of those two 

methods. Regardless of the field method chosen, 

the use of plot or transect-based field surveys 

should be incorporated with remote sensing 

data, which is becoming an important tool for 

monitoring vegetation change (Frohn 1998). 

Great attention should be paid in the 

planning process for vegetation monitoring 

to ensure that enough plots are surveyed to 

adequately capture the diversity of vegetation 

structure and composition represented in the 

district. An evaluation of our results clearly 

indicates that five line-intercept transects and 

modified-Whittaker plots was insufficient to 

capture this spatial diversity (Figs. 3.4, 3.5) 

and is inadequate for a rigorous long-term 

monitoring program. We suggest that monitoring 

be particularly focused on areas on and around 

Wasson Peak where impacts of global climate 

change are likely to be greatest. In addition to 

establishing long-term monitoring sites for the 

I&M program, we encourage the I&M network 

to continue the work by Funicelli et al. (2001) 

by reading those saguaro plots at least every 10 

years.
21

Previous Research

The Tucson Mountains are well known to 

herpetologists, and several species lists exist for 

Saguaro National Park (e.g., Doll et al. 1986, 

Lowe and Holm 1991, Swann 2004), yet little 

information is available on distribution and 

abundance of amphibians and reptiles (hereafter 

“herpetofauna”) in the Tucson Mountain District. 

Lowe and Holm (1991) ranked abundance (e.g. 

rare, uncommon, and common) of herpetofauna 

known to occur in Tucson Mountain District, but 

abundance categories were not based on field 

observations. Therefore, our effort represents 

the first attempt to quantify relative abundance 

and species richness of herpetofauna in the 

Tucson Mountain District and to provide a welldocumented species list.

Methods

We surveyed herpetofauna in 2001 and 2002 

using four field methods. These included 

intensive plot-based surveys and more flexible 

extensive non-plot based surveys (Table 4.1), 

as well as pitfall trapping and road surveys. 

We used multiple methods to describe species 

richness and relative abundance because temporal 

and spatial variation in detectability is high, 

both within and among species. We selected 

intensive plot-based survey locations at random 

and constrained the surveys by time and area 

(Crump and Scott 1994). Extensive, non-plotbased survey locations were selected randomly 

and non-randomly and allowed variation in time 

and area to better detect rare and elusive species. 

For road surveys and extensive surveys we used 

both diurnal and nocturnal surveys to detect 

species with restricted activity periods (Ivanyi et 

al. 2000). Although techniques were designed 

to detect both amphibians and reptiles, fewer 

amphibians were detected as they have more 

restrictive activity periods. 

Sampling Designs

We selected random and non-random survey 

areas. Randomization allowed inference to 

the entire district and facilitated comparisons 

among parks. Non-random selection allowed 

inclusion of areas, such as seeps or areas with 

unique geology that have relatively low landscape 

coverage but may have high species richness and 

abundance or include rare species not previously 

recorded. For road surveys, we constrained effort 

to paved and unpaved public roads within the 

district and along the district boundary. 

Intensive Surveys

Field Methods

In 2001, we used plot-based visual encounter 

surveys constrained by time and area to 

standardize effort (Crump and Scott 1994). 

Surveys were confined to 1-ha (100 x 100 m) 

subplots and searched for one hour (see Chapter 

1 for discussion of location of focal-point 

transects). If dangerous topography prevented a 

survey in one of these subplots, we surveyed an 

adjacent subplot. 

Chapter 4: Amphibians and Reptiles

Aaron D. Flesch, Don E. Swann, and Brian F. Powell

Table 4.1. Characteristics of three major active survey methods used during surveys for herpetofauna, Saguaro NP, 

Tucson Mountain District, 2001 and 2002. 

Survey type

Characteristic Intensive, plot-based Extensive – Random Extensive – Non-random

Random location Yes Partially No

Area constrained Yes No No

Configuration Plot-based visual encounter Non-plot-based visual encounter Non-plot-based visual encounter

Area (ha) three 1-ha plots per transect Variable Variable

Time constrained Yes, 1 hour No No

Time of day Morning Morning Morning, afternoon, and evening 

Advantages

Facilitates comparison with other areas, 

scope of inference to entire district, more 

complete richness and abundance data

Larger scope of inference and potential 

to detect less common species 

Maximum flexibility facilitating 

detection of rare species with 

restricted distributions 

Disadvantages Inefficient for developing complete 

species list

Inefficient for developing complete 

species list

Scope of inference applies only to 

those areas surveyed
22

We surveyed three subplots per focal-point 

transect (FPT) in spring (11 - 18 April) and two 

subplots per FPT during the summer monsoon 

season (16 - 24 July). Only the two end subplots 

(1 and 10) were surveyed in summer because 

there was not sufficient time during peak activity 

periods to search all three. We selected survey 

times that coincided with periods of peak diurnal 

reptile activity because activity levels vary with 

temperature. On cooler spring days we began 

our surveys between 0740 and 1405 whereas on 

hotter, summer days we began between 0618 

and 0851. To account for within-day variation 

in detectability and to reduce observer bias, 

each subplot was surveyed twice per day by a 

different observer. We did not conduct nocturnal/

crepuscular intensive surveys. 

We searched subplots visually and aurally 

and worked systematically across each subplot. 

We used a Garmin E-map GPS to ensure we 

stayed within subplot boundaries during surveys. 

We also looked under rocks and litter and used 

a mirror to illuminate cracks and crevices. For 

each animal detected, we recorded species, sex 

and age/size class (if known), and microhabitat 

(ground, vegetation, rock, edifice, burrow, or 

water). We marked subplot corners with rubbercapped stakes and recorded UTM coordinates 

with a Trimble GPS. We recorded temperature, 

wind speed (km/h), percent relative humidity, 

and percent cloud cover using hand-held Kestrel 

3000 weather meters (Nielson-Kellerman Inc., 

Boothwyn, PA) before and after surveys. We also 

described vegetation and soils. 

Effort

We completed 42 one-hour surveys at 15 subplots 

located along 5 FPTs (Table 4.2; Fig. 4.2). We 

surveyed all 5 FPTs in spring and only 3 FPTs 

in summer. In 2002 we discontinued intensive 

surveys, because of the relatively low number of 

species detected, and instead focused on other 

methods.

Analysis

We calculated abundance by summing detections 

for each species for the two or three subplots 

per FPT. Because we surveyed subplots twice 

per day to account for within-day variation in 

detectability, we used the maximum number 

of individuals detected on either survey for 

each visit because it reflected abundance when 

detectability was highest (Rosen and Lowe 1995). 

We estimated relative abundance (no/ha/hr) 

for each species (and all species combined) by 

averaging the maximum number of individuals 

detected on repeated visits to each FPT, then 

averaging among all FPTs. We present estimates 

by season (spring vs. summer) and for both 

seasons combined. 

Extensive Surveys

Non-plot-based extensive surveys facilitated 

sampling in areas with low landscape coverage 

where we expected high species richness, 

abundance, or species not previously detected. 

Typically, we selected areas for extensive 

surveys in canyons or riparian areas but also 

included ridgelines, cliffs, rock piles, bajadas, 

or other features. We based extensive surveys 

Transect

line

1000 m 

1 2 3 4 5 6 7 8 9 10

Subplot number 

Focal

Point

100 m 

100 m 

Figure 4.1. Typical plot layout of herpetofauna subplots along a 1-km focal-point transect (n = 5), Saguaro NP, 

Tucson Mountain District. We surveyed three 100 x 100 m subplots (dotted boxes) in spring and two subplots (1 and 

10) in summer. 
23

on visual encounters (Crump and Scott 1994) 

and in contrast to intensive surveys, they were 

not constrained by area or time. We focused 

extensive surveys during mornings and also 

included evenings and nights when detectability 

of snakes and amphibians is highest (Ivanyi et al. 

2000). 

Field Methods

We located extensive surveys randomly and nonrandomly. Random surveys were located within 

approximately 1 to 2 km of FPTs used during 

intensive surveys and were conducted on one 

occasion. Non-random surveys were selected 

using topographic maps and prior knowledge 

and have been referred to as “special areas” in 

previous reports (Powell et al. 2002, 2003). We 

relied upon visual detection of herpetofauna 

during extensive surveys and often looked under 

objects and illuminated cracks to detect hidden 

individuals. We began morning surveys before 

1000 hrs and afternoon surveys after 1630 hrs to 

avoid the hottest times of day. We also surveyed 

Figure 4.2. Study site locations for herpetofauna, Saguaro NP, Tucson Mountain District, 2001 and 2002.
24

in late evenings and nights especially after the 

onset of the summer monsoon. We surveyed in 

spring (11–14 April) and summer (2 July – 25 

September) of 2001 and 2002. Survey duration 

averaged 3.1 ± 0.2 (± SE) hrs and ranged from 

1.3 to 6.2 hrs. One, two, or three observers 

searched areas simultaneously and recorded 

data separately. We recorded data using similar 

methods as intensive surveys and noted UTM 

coordinates and elevation at start and end points 

of each survey. We also classified survey areas 

by topographic formation (Lowe 1992) and 

considered two formations found in the Tucson 

Mountain District, bajada and rocky mountain, as 

well as the transition zone between them (within 

≈1 km of either formation). 

Effort

We surveyed 55 areas in 2001 and 2002, 90% of 

which were surveyed in 2001 (Table 4.2). Total 

survey effort was 224.7 hrs, 89% of which was 

in non-random extensive areas. Survey effort for 

extensive surveys was roughly 3 times greater 

than for other methods. 

Analysis

We calculated relative abundance as number 

of individuals detected for each species or all 

species combined per 10 hrs of effort. For 

surveys completed by >1 observer per survey 

area, we summed survey time and detection 

data for all surveyors when calculating effort 

and relative abundance for the area. To describe 

patterns of relative abundance and species 

richness across the district, we post-stratified 

survey areas by topographic formation and used 

one- or two-way ANOVA and linear contrasts to 

test for variation among formations. To describe 

patterns of relative abundance across elevation 

we used multiple linear regression. Because 

patterns of relative abundance often varied with 

temperature, relative humidity, and time of day 

we adjusted for their influence when necessary 

and report least square means which are adjusted 

for other important model parameters. To adjust 

for temporal variation in relative abundance we 

considered three time periods: day, late evening 

or night, or surveys that spanned portions of 

both periods. We considered 20 min before local 

sunset time as the cut-point between day and 

late evening surveys. Although we surveyed 

some areas multiple times within and between 

years, survey routes often varied. We therefore 

considered each survey as an independent sample 

despite some spatial overlap. 

Road Surveys 

Driving roads is a common method for surveying 

for herpetofauna and is recommended for 

augmenting species richness information in 

conjunction with other methods (Shaffer and 

Juterbock 1994). Road surveys involve driving 

slowly along a road, typically after sunset, and 

watching for animals. 

Field Methods

We drove Golden Gate, Hohokam, Kinney, 

Picture Rocks, and Sandario roads and focused 

primarily on Kinney, Hohokam, and Golden 

Gate roads for safety reasons because of the high 

volume of traffic on the other roads. Because 

some bajada species, especially leaf-nosed snakes 

(genus Phyllorhynchus), would mostly likely be 

seen on Sandario Road, this may have caused us 

to miss them. We recorded weather information 

at beginning and end points of each survey as 

described in other methods. We recorded each 

Table 4.2. Herpetofauna survey effort by method and year, Saguaro NP, Tucson Mountain District, 2001 and 2002. 

2001 2002

Survey method Elevation range (m)

No. of samples 

(subsamples)a

Survey 

hours

No. of samples 

(subsamples)a

Survey 

hours

Intensive survey 680 - 1108 5 (15) 42.0 0 0.0

Extensive survey – random 670 - 1067 5 (11) 25.5 0 0.0

Extensive survey – non-random 671 - 1219 44 174.7 8 24.5

Road cruising 670 - 768 1 34.2 1 4.9

Pitfall array 700 1 76.0 1 280.0 a Number of subsamples for random surveys equals number of subplots for intensive surveys and number of survey areas for 

extensive surveys.
25

individual detected by species and whether it was 

found alive or dead. We surveyed between 12 

April and 24 August and began surveys during 

evenings or nights and ended surveys during 

nights.

Effort

We conducted 21 road surveys totaling 39.1 hrs 

of effort (Table 4.2).

Analysis

Because survey routes varied in length and 

included a number of different segments surveyed 

in various orders, we pooled results from all 

routes and road segments. Mileage for each 

route was not recorded so we scaled estimates 

of relative abundance by time. We calculated 

relative abundance as the number of individuals 

detected for each species (or all species 

combined) per hour of survey effort. 

Pitfall Trapping

Pitfall trapping is a live-trap, passive sampling 

technique useful for detecting species that are 

difficult to observe due to rarity, limited activity, 

or inconspicuous behavior (Corn 1994). 

Field Methods

We constructed 1 pitfall trap array with three 

19-L buckets spaced 8 m apart at angles of 

approximately 120 degrees from a central bucket. 

We dug shallow trenches connecting the central 

buckets to each outside bucket and placed drift 

fences (7.6-m long, 0.5-m tall aluminum-flashing 

supported by rebar) in each trench. We buried 

buckets so that their edges were at ground level 

and placed cover boards (50 x 50-cm pieces of 

plywood) over them to keep animals cool during 

the day (Corn 1994). 

To capture large snakes and other animals 

capable of escaping trap buckets, we placed one 

wire-mesh funnel-trap (tubes with inwardlydirected cones at each end) at midpoints along 

each side of drift fences (n = 6 traps) (Corn 

1994). Animals entering funnels fell to the 

bottom of tubes and were unable to escape. 

We typically opened traps around sunset and 

checked and closed traps either around midnight 

or the following morning. We recorded species, 

sex, and age class (if known) for each animal 

captured.

Effort

The trap array was located on the bajada, 

west of Sandario Road and south of Manville 

Road (UTM 477739 m E, 3571005 m N) at 

700-m elevation (Fig. 4.2). We operated traps 

for 9 nights totaling 76 hrs from 2 July to 22 

September 2001 and for 16 nights totaling 280 

hrs from 2 August to 6 October 2002. Mean 

start time was 1809 ± 0.34 hrs. We closed traps 

around midnight on eight occasions and after 

sunrise on 17 occasions. 

Analysis

We report number of animals captured per 

100 hrs of trap array operation by species and 

taxonomic group. 

Vouchers 

We collected both voucher specimens and analog 

voucher photographs. All voucher specimens 

were prepared with formalin, tagged, placed 

in alcohol, and deposited in the University of 

Arizona’s herpetology collection. Specimen tags 

included collector’s name, species, date, and 

location of each specimen. To prioritize species 

for voucher collection, we first searched Saguaro 

National Park’s specimens, university collections, 

and the NPS Inventory and Monitoring database 

NPSpecies to create a list of species that had 

already been collected in the district. Voucher 

specimens are important to verify species 

identifications and can be useful if species are 

reclassified and split into multiple species; all the 

specimens we collected at the district had been 

killed on park roads by cars.

We also obtained voucher photographs 

for each species we were able to capture. We 

obtained a close-up photograph of each animal 

“in hand” and, if possible, another photograph of 

the animal in natural surroundings. We recorded 

the same information for each voucher photo as 

above. In addition to documenting most species, 

these photos should be useful for interpretive 

purposes at the park. 

Incidental Observations

We noted sightings of rare or important species 

by sex and age class (if known) and recorded 

time of observations and UTM coordinates 

for all detections. These incidental detections 
26

were often recorded before or after more formal 

surveys and were used in determining species 

richness and distribution. To complete the 

species list, we relied on incidental observations, 

voucher specimens, and voucher photographs 

collected by Saguaro National Park staff (Don 

Swann) during the inventory period.

Species Identifications

The most challenging reptiles to identify in the 

district are whiptail lizards (Cnemidophorus

spp.). Many parthenogenetic (non-sexuallyreproducing) whiptail species may have arisen 

as hybrids from the same diploid, sexuallyreproducing parent species (Degenhardt et al. 

1996) and several undescribed “parthenospecies” 

may exist in the desert southwest. Systematics of 

genus Cnemidophorus (Aspidoscelis according to 

some sources) remains challenging (Wright 1993) 

and some individuals we identified as western (C. 

tigris) or Sonoran spotted (C. sonorae) whiptails 

may be undescribed “species”. On the district 

we saw “classic” Sonoran whiptails (adults with 

six longitudinal dorsal stripes, light spots in dark 

and occasionally light dorsal areas; dorsal stripes 

more yellow anteriorly; overall color was brown 

dorsally and unmarked white-cream ventrally; tail 

was more brownish-orange than bluish as seen in 

Gila spotted whiptails; Degenhardt et al. 1996, 

Phil Rosen pers. obs.) and a variation of this 

classic appearance (possibly older individuals) 

that superficially resembled Gila spotted whiptails 

(C. flagellicaudus). In this document we report 

all of these individuals as Sonoran whiptails. 

Results

We detected 34 species of herpetofauna, four 

amphibian and 30 reptile species (Appendix 

B). Reptile species included one tortoise, 14 

lizard, and 15 snake species. The greatest 

number of species (29) was detected during 

extensive surveys. Road cruising and pitfall 

trapping resulted in detection of one additional 

species (Couch’s spadefoot toad) and incidental 

observations resulted in detection of four 

additional species (Great Plains toad, Sonoran 

whipsnake, western lyre snake, and Sonoran coral 

snake) not detected using other methods. All 14 

species detected during intensive surveys were 

observed using other methods. 

We detected 1,397 individuals during 

intensive, extensive, road cruising, pitfall 

trapping efforts, and 305 incidental detections 

during the study. Most individuals (1,037) 

were detected during extensive surveys and the 

fewest (20) were detected during pitfall trapping 

(Table 4.3). The number of individuals detected 

per unit time was greatest for intensive surveys 

(6.3 individuals/hr) and roughly 27% lower for 

extensive surveys (4.6 individuals/hr). Efficiency 

was lowest for pitfall trapping with only 0.1 

individuals detected per hour (0.8 individuals per 

trap night). 

Intensive Surveys

We detected 264 animals and 14 species along 

five FPTs (Table 4.4). Lizards were most 

common and comprised 64.3% (n = 9 of 14) 

of species and 96.2% (n = 254 of 264) of 

individuals. We recorded no amphibians during 

intensive surveys. Relative abundance averaged 

7.7 ± 2.6 individuals/ha/hr (range = 1.5–16.3) and 

was similar between seasons. 

Western whiptail, zebra-tailed lizard, and 

side-blotched lizard were most common (≥37 

detections), whereas Gila monster, coachwhip, 

western patch-nosed snake, and gopher snake 

were rarest (1 detection each). Western diamondbacked rattlesnake was the most common snake 

and was detected in both spring and summer. 

Relative abundance appeared to vary between 

seasons for some of the most common species 

(Table 4.4). Relative abundance of ornate tree 

lizards, for example, was 1.8 times greater in 

spring whereas relative abundance of sideblotched lizards was 5 times greater in summer. 

Ornate tree lizards were the only species 

found on all FPTs whereas zebra-tailed lizard 

occurred on 80% (n = 4 of 5) of FPTs. All 

snake species were found on only one FPT each. 

Clark’s spiny lizards occurred on three FPTs 

whereas desert spiny lizard occurred on two and 

occurrence of these species overlapped along one 

FPT. 
27

Extensive Surveys

We detected 1,037 animals of 29 species during 

55 surveys in 2001 and 2002 (Table 4.5). We 

recorded only 2 amphibian species during 

extensive surveys, Sonoran desert toad and 

red-spotted toad. Reptile species included one 

tortoise, 14 lizards, and 12 snakes. Eighty seven 

percent (n = 909 of 1,037) of individuals detected 

were lizards. The most common species were 

the same as for intensive surveys: zebra-tailed 

lizard, western whiptail, and side-blotched lizard, 

and the western diamond-backed rattlesnake was 

the most common snake. Relative abundance of 

the zebra-tailed lizard was roughly three times 

higher than that of the next most common species 

(western whiptail). Blind snake, glossy snake, 

sidewinder, and Mohave rattlesnake were least 

abundant (1 detection each). 

Most surveys were during the day (45.5%) 

with fewer during the late evening or night 

(32.7%) or spanning both periods (21.8%). 

Relative abundance varied among time periods 

for lizards and snakes (F2, 52 ≥ 3.61, P ≤ 0.034, 

ANOVA) with more lizards detected during the 

day and more snakes detected during the night 

than during other periods. Further, species 

richness varied among time periods (F2, 52 = 3.12, 

P = 0.053, ANOVA) and averaged 36% greater 

for surveys during both day and night. We 

therefore adjusted for the influence of survey time 

in all comparisons.

Relative abundance of amphibians 

increased by 2.9 ± 0.7 individuals/10 hrs with 

Table 4.3. Number of animals and species detected per hour by method and year, Saguaro NP, Tucson Mountain 

District, 2001 and 2002. 

2001 2002

Survey type

Animals 

detected

Animals 

per 

hour 

Species 

detected

Species 

per 

hour 

Animals 

detected

Animals 

per 

hour 

Species 

detected

Species 

per 

hour 

Intensive survey 264 6.3 14 0.33

Extensive survey 909 4.5 30 0.15 128 5.2 15 0.61

Road cruising 72 2.1 15 0.44 4 0.8 3 0.61

Pitfall array 4 0.1 4 0.05 16 0.1 8 0.03

Table 4.4. Relative abundance (mean and SE; no./ha/hr) of herpetofauna detected during intensive surveys along 

random focal-point transects (n = 5) in spring (11-17 April) and summer (16-24 July) 2001, Saguaro NP, Tucson 

Mountain District. 

Spring (n = 5) Summer (n = 3) All seasons

Species mean SE mean SE mean SE

desert iguana 0.07 0.07 0.33 0.33 0.20 0.20

zebra-tailed lizard 1.87 0.65 2.17 1.17 2.20 0.79

desert spiny lizard 0.13 0.08 0.13 0.08

Clark’s spiny lizard 0.33 0.15 0.17 0.17 0.37 0.15

side-blotched lizard 0.60 0.31 3.00 1.89 1.93 1.23

ornate tree lizard 1.20 0.13 0.67 0.17 1.20 0.13

regal horned lizard 0.17 0.17 0.10 0.10

western whiptail 2.27 1.94 3.33 1.58 3.00 1.85

Gila monster 0.07 0.07 0.07 0.07

coachwhip 0.07 0.07 0.07 0.07

western patch-nosed snake 0.07 0.20 0.07 0.07

gopher snake 0.07 0.07 0.07 0.07

western diamond-backed rattlesnake 0.13 0.13 0.17 0.17 0.13 0.13

tiger rattlesnake 0.17 0.17 0.10 0.10

all individuals 6.67 2.59 8.67 3.81 7.67 2.62
28

each 10% increase in mean relative humidity after 

adjusting for survey time (t

51 = 4.07, P = 0.0001, 

test of slope from multiple linear regression) and 

amphibians were only detected during extensive 

surveys in July when mean relative humidity was 

1.8 times greater than during other months (t

51

= 3.34, P = 0.0016, linear contrast). There was 

no evidence that relative abundance of snakes 

varied with temperature or relative humidity (t

51

≤ 1.08, P ≥ 0.29) and some evidence that relative 

abundance of lizards increased with relative 

humidity (estimate = 1.1, SE = 0.6, t

51 = 1.71, P = 

0.093), after adjusting for survey time. 

Relative abundance averaged 61.0 ± 8.8 

individuals/10 hrs (range = 0 – 415) and varied 

among topographic formations (F4, 46 = 3.76, P

= 0.030, 2-way ANOVA). Relative abundance 

was more than two times higher on the bajada 

(least squared mean ± SE = 91.0 ± 15.2) than in 

the mountains (40.4 ± 14.2) or at the edge of the 

mountains (41.1 ± 13.9) (t

50 = 2.74, P = 0.0085) 

and attributable mainly to increased relative 

abundance of lizards which was 2.8 times greater 

on the bajada. Relative abundance of snakes 

varied among topographic formations (F4, 46 = 

3.53, P = 0.037, 2-way ANOVA) and was 3.7 

times greater on the bajada (7.7 ± 1.5) than in the 

mountains (2.2 ± 1.4) and moderate at the edge 

(5.1 ± 1.4). Species richness was similar among 

topographic formations except for snakes, which 

averaged 2.5 times higher on the bajada (1.7 ± 

0.2) than in the mountains (0.6 ± 0.2) (F4, 46 = 

4.08, P = 0.023, 2-way ANOVA). 

Patterns of species occurrence and relative 

abundance often varied among topographic 

formations and across elevation. Relative 

abundance of desert iguana, Sonoran spotted 

and western whiptail, desert and Clark’s spiny 

Table 4.5. Relative abundance (mean + SE; no./10 hrs) of amphibians and reptiles detected during extensive surveys 

(n = 55), by topographic formation, Saguaro NP, Tucson Mountain District, 2001 and 2002. 

Bajada (n = 17) Edge (n = 21) Mountain (n = 17) All surveys (n = 55)

Species Mean SE Mean SE Mean SE Mean SE

Sonoran desert toad 0.08 0.08 0.34 0.34 0.06 0.06 0.17 0.13

red-spotted toad 0.49 0.49 0.68 0.68 4.44 3.20 1.78 1.04

desert tortoise 0.67 0.31 0.06 0.06 0.27 0.13

western banded gecko 0.57 0.32 0.44 0.35 0.44 0.33 0.48 0.19

desert iguana 0.80 0.39 0.25 0.13

Sonoran collared lizard 0.51 0.40 0.16 0.13

long-nosed leopard lizard 0.11 0.11 0.03 0.03

lesser earless lizard 0.08 0.08 0.14 0.14 2.74 1.89 0.93 0.60

zebra-tailed lizard 14.88 5.32 25.86 7.90 11.03 3.76 17.88 3.67

desert spiny lizard 3.09 1.08 0.14 0.14 0.21 0.21 1.07 0.38

Clark’s spiny lizard 0.26 0.26 2.01 0.70 4.96 2.17 2.38 0.76

side-blotched lizard 7.46 2.89 4.49 1.08 1.92 0.80 4.61 1.04

ornate tree lizard 0.83 0.36 6.52 3.07 2.58 1.87 3.54 1.33

regal horned lizard 0.44 0.25 0.17 0.10

Sonoran spotted whiptail 0.19 0.19 1.48 0.67 0.53 0.23

western whiptail 13.15 5.42 6.59 1.90 0.74 0.35 6.81 1.91

Gila monster 0.61 0.33 0.55 0.49 0.36 0.18

western blind snake 0.07 0.07 0.02 0.02

coachwhip 0.22 0.13 0.54 0.25 0.28 0.11

western patch-nosed snake 0.19 0.09 0.07 0.04

gopher snake 0.21 0.14 0.06 0.05

glossy snake 0.12 0.12 0.04 0.04

long-nosed snake 0.95 0.44 0.29 0.15

night snake 0.23 0.17 0.07 0.05

western diamond-backed rattlesnake 2.28 0.72 1.53 0.72 1.00 0.43 1.60 0.38

sidewinder 0.15 0.15 0.05 0.05

black-tailed rattlesnake 0.10 0.10 0.12 0.12 0.08 0.05

tiger rattlesnake 0.12 0.12 0.06 0.06 0.07 0.05

Mohave rattlesnake 0.03 0.03 0.01 0.01

all individuals (no/10 hr) 80.34 23.97 60.36 10.50 42.55 7.55 61.03 8.80

species richness 22 19 17 30
29

lizard, side-blotched lizard, and long-nosed 

snake varied among topographic formations (P

≤ 0.044, ANOVA) (Table 4.5). Sonoran spotted 

whiptail and Clark’s spiny lizard were most 

common in the mountains, and western whiptail 

and desert spiny lizard were most common on 

the bajada. Nine species were detected only on 

the bajada whereas one was detected only in the 

mountains. Relative abundance increased with 

elevation for four species (red-spotted toad, lesser 

earless lizard, Clark’s spiny lizard, and Sonoran 

spotted whiptail) and decreased with elevation for 

another four species (desert iguana, desert spiny 

lizard, side-blotched lizard, and western whiptail) 

(P ≤ 0.049, test of slope from simple linear 

regression). 

When comparing areas selected at random 

(n = 11) to those selected non-randomly (n = 

44), species richness in non-random survey areas 

(least square mean = 4.9 ± 0.3 species) was 3.5 

times greater than in random areas (F3, 51 = 20.4, 

P < 0.0001) after adjusting for the influence of 

survey time. We detected 11 species in random 

areas, all of which were detected in nonrandom 

areas, and six of which were detected during 

intensive surveys. Relative abundance was over 

six times greater in nonrandom areas for all 

species groups combined (F4, 50 = 9.11, P = 0.004) 

after adjusting for the influence of survey time 

and relative humidity. 

Road Surveys

We detected 76 animals representing 15 species. 

We recorded three amphibian species represented 

by 20 individuals (26.3% of all individuals) while 

driving roads, proportionally more than for other 

survey methods (Table 4.6). Reptiles included 

seven lizard and five snake species; 44.7% (n = 

34 of 76) of individuals were lizards and 28.9% 

(n = 22 of 76) were snakes, proportionally more 

snakes than for other survey methods. Relative 

abundance averaged 1.9 ± 0.2 individuals/hr 

(range = 0.3–5.0). 

Relative abundance did not vary between 

seasons during road surveys (t

19 = 0.067, P = 

0.95, t-test), yet all amphibians were detected 

during summer. Western diamond-backed 

rattlesnake, zebra-tailed lizard, and red-spotted 

toad were the most common species detected 

(14 detections each). Western patch-nosed 

snake, black-tailed rattlesnake, and side-blotched 

lizard were the least abundant species with one 

detection each.

Pitfall Array

We trapped 20 individuals of eight species during 

25 nights of effort in 2001 and 2002. Species 

composition reflected that generally found on the 

bajada. Zebra-tailed lizard and desert spiny lizard 

were most common whereas Couch’s spadefoot 

toad, western blind snake, and long-nosed snake 

were least common (Table 4.7). Pitfall trapping 

was the least efficient method in terms of number 

of species and total individuals detected per unit 

time, but because effort was mainly passive, 

comparisons with other methods are difficult. 

Incidental Observations

We recorded 305 incidental observations of 28 

species between 4 April 2001 and 1 October 2002 

(Appendix B). Four species (Great Plains toad, 

Sonoran whipsnake, western lyre snake, and 

Sonoran coral snake) were only detected through 

this method, each by a single individual. 

Vouchers

We collected eight voucher specimens in 2001 

and 2002 and obtained records of nine other 

vouchers collected between 1968 and 2000 

(Appendices E and F). All vouchers obtained in 

2001 and 2002 were already dead when collected 

and are accessioned in the University of Arizona 

Herpetology Collection (UAZ). A voucher 

specimen was also located for the variable 

sandsnake (Chilomeniscus cinctus), a species 

not documented during this study. Sonoran mud 

turtle (Kinosternon sonoriense) was documented 

by a photograph at King’s Canyon seep in 1997, 

but was not detected by us. 

We obtained 51 voucher photos of 29 

species during 2001 and 2002 (Appendix E). All 

voucher photos are stored digitally and in 35 mm 

color slide format in the I&M office in Tucson. 

Inventory Completeness

Based on extensive previous collecting in the 

Tucson Mountains, we believe that we detected 

most of the species that occur in the district. We 
30

detected 34 of the 37 species ever documented 

for the Tucson Mountain District. Of the species 

not detected by us, one species, the common 

kingsnake, is certainly present because it has 

been observed several times on roadkill surveys 

by park staff during the past decade. This snake 

may have been missed because it is not very 

common, especially during drought years. We 

also missed the variable sandsnake, which is 

known to be relatively abundant in the district. 

This small, highly sedentary reptile is primarily 

found by road-driving in May and early June, 

and might have escaped detection in a sampling 

effort focused on April and July. This sampling 

regimen might also help to account for the 

absence of the saddled leaf-nosed snake in our 

observations (but see below). We do not believe 

that there is adequate aquatic habitat in the 

district to support a population of Sonoran mud 

turtle; the individual photo-documented in King’s 

Canyon in 1997 could have escaped from the 

nearby Arizona-Sonora Desert Museum (ASDM) 

or may have been an emigrant from the Avra 

Valley where small populations may occur (Phil 

Rosen, pers. comm.). 

Several species that we did not find have 

never been documented, but may occur in the 

district. Of these, existing data (Stebbins 2003) 

and personal observations by local herpetologists 

(e.g., Cecil Schwalbe) indicate that two 

species of snakes that spend most of their time 

underground,could occur at the district:

•	 western groundsnake (Sonora 

semiannulata) occurs in desert grassland 

and mesquite bottoms mid-valley, but is 

poorly known regionally and thus could 

possibly occur in the district; and

Table 4.7. Relative abundance (no./100 hrs) of animals trapped in pitfall trap array 

(n = 1) in Saguaro NP, Tucson Mountain District, 2001 and 2002. 

Taxon Species

Total 

captures 2001 2002

Amphibian Couch’s spadefoot toad 1 0.4

Reptile western banded gecko 3 1.3

zebra-tailed lizard 4 1.3 1.1

desert spiny lizard 4 1.3 1.1

side-blotched lizard 3 1.3 0.7

western whiptail 3 1.1

western blind snake 1 0.4

long-nosed snake 1 0.4

Table 4.6. Relative abundance (no./hr) of amphibians and reptiles detected during 

road surveys in Saguaro NP, Tucson Mountain District, 2001 and 2002. 

Taxon Species Mean SE

Amphibian Couch’s spadefoot toad 0.05 0.04

Sonoran desert toad 0.15 0.09

red-spotted toad 0.24 0.15

Reptile western banded gecko 0.10 0.08

zebra-tailed lizard 0.26 0.14

desert spiny lizard 0.04 0.03

side-blotched lizard 0.01 0.01

regal horned lizard 0.10 0.04

western whiptail 0.03 0.03

Gila monster 0.15 0.08

western patch-nosed snake 0.04 0.04

long-nosed snake 0.09 0.05

western diamond-backed rattlesnake 0.39 0.12

black-tailed rattlesnake 0.01 0.01

tiger rattlesnake 0.12 0.08
31

•	 southwestern black-headed snake (Tantilla 

hobartsmithi) which occurs along the Santa 

Cruz River and may be found in major 

canyons in the district. 

Two non-native species seem likely, but may 

depend on the presence of humans:

•	 spiny-tailed iguana (Ctenosaura hemilopha) 

have escaped from the grounds of the 

ASDM just outside the district, and some 

individuals may move into the district at 

King’s Canyon, and 

•	 Mediterranean gecko (Hemidactylus 

turcicus) occur in and near human-made 

structures and thus occur near the district. 

Mediterranean gecko likely occurs 

occasionally in the district already (Phil 

Rosen, pers. comm.).

The Tucson Mountains are fascinating in 

terms of reptile and amphibian biogeography, 

which makes it difficult to assess the 

completeness of our inventory. The mountains 

lie within the Sonoran Desert, but on the edge 

of several other major biogeographic provinces, 

including the Rocky Mountain region to the north 

and east; the Chihuahuan Desert to the east, and 

the Madrean “sky island” region to the south 

(Shreve 1951, Brown 1994). In addition, the 

Santa Cruz River, historically the site of a major 

desert riparian area, stream, cienega, agricultural 

landscapes, and grassland bottoms, runs along the 

east side of the Tucson Mountains. As a result, 

the district is near the edge of the geographic 

distribution of a large number of amphibians and 

reptile species. Some representatives of each of 

the four major regions are present, while others 

occur nearby but appear to not be present in the 

district. For example, sidewinder and desert 

iguana occur at the district, but not further east 

into the Tucson Basin. 

A large number of other species have been 

found just west and/or north of the district, but 

were not documented in our inventory or in other 

previous surveys. These species may be found 

in the northwest part of the district, in or near 

creosotebush-dominated flats and lower bajadas 

(distribution information from Phil Rosen, pers. 

comm.):

•	 long-tailed brush lizard (Urosaurus 

graciosus), which still occurs at the north 

point of the Tucson Mountains near the 

Santa Cruz River;

•	 desert horned lizard (Phrynosoma 

platyrhinos), which occupied flats and 

lower bajada and may also be locally 

extirpated; 

•	 western shovel-nosed snake (Chionactis 

occipitalis), which occupied the valleycenter desertscrub flats but may now be 

extirpated;

•	 spotted leaf-nosed snake (Phyllorhynchus 

decurtatus), which may have reached its 

eastern range limit near Sandario Road on 

lower to middle bajadas; and

•	 saddled leaf-nosed snake (Phyllorhynchus 

browni) was abundant on Silverbell Road 

at least through the late 1960’s (Steve 

Goldberg, personal comm. to Phil Rosen, 

1996), but was virtually absent along both 

sides of the river during the 1990s (Rosen, 

unpublished data). 

Both leaf-nosed snakes could occur on 

the sandy-loam bajadas on the west side of the 

district. Leaf-nosed snakes are especially active 

at night (often late at night) from late May 

through July, and they could have been at a low 

abundance during the drought that was ongoing at 

the time of our surveys. The common chuckwalla 

(Sauromalus obesus), a large and conspicuous 

species associated with desert rockpiles (Rosen 

2003), is found on the west side of Avra Valley 

and is not likely to be in the district. 

 The Tucson Mountain District also contains 

species typically associated with the Chihuahuan 

rather than the Sonoran Desert, including lesser 

earless lizard, but the district does not have 

others, including: 

•	 greater earless lizard (Cophosaurus 

texanus), which is common only a few 

miles away in the desert grassland environs 

of the Tortolita and Santa Catalina 

Mountains. 

Similarly, species present at lower 

elevations in the Madrean “sky islands” occur 
32

at the district, including the Clark’s spiny lizard 

and the Sonoran whipsnake, both of which are 

associated with rocky slopes in the Arizona 

Uplands. However, several species not found in 

the district include:

•	 Madrean alligator lizard (Elgaria kingii), 

which occur at low elevations of Rincon 

Mountain District of Saguaro NP, 

•	 ring-necked snake (Diadophis punctatus), 

mostly a temperate-zone species associated 

with forest and grassland that occurs in the 

Tortolita, Rincon, and Catalina mountains; 

and 

•	 western box turtle (Terrapene ornata), 

a grassland species that had riparian 

populations in the Sonoran Desert along 

Rillito and Sabino creeks and the Santa 

Cruz River, including within a few km of 

the district boundary (Don Swann, pers. 

obs.). 

All these species are usually associated with 

grassland, woodland, and forest, and were known 

or likely to have been present on the Santa Cruz 

River in its wetland and riparian areas prior to the 

river’s degradation during the 20th century. When 

these species occurred along the river, occasional 

individuals may have entered the district, but 

these species probably would not have had viable 

populations within its boundaries.

A large number of species of reptiles and 

amphibians found in the Rincon Mountain 

District have not been documented in the TMD. 

Most of these are unlikely to occur because they 

are outside of their geographical or elevational 

range limits. Also, a number do not occur 

because suitable aquatic habitat is lacking. 

Historically, riparian species such as the lowland 

leopard frog (Rana yavapaiensis), Sonoran 

green toad (Bufo retiformis), Woodhouse’s 

toad (Bufo woodhousii), Great Plains narrowmouthed toad (Gastrophryne olivacea), Mexican 

spadefoot (Spea multiplicata), Sonoran mud 

turtle (Kinosternon sonoriense), Mexican garter 

snake (Thamnophis eques), checkered garter 

snake (T. marcianus), black-necked garter 

snake (T. cyrtopsis), canyon spotted whiptail 

(Cnemidophorus burti) and the southern prairie 

lizard (Sceloporus undulatus consobrinus) 

occurred along the Santa Cruz River near the 

district (Rosen and Mauz 2001). A few of these 

species still occur and could be rare or occasional 

in the district, such as the narrow-mouthed or 

Mexican spadefoot toads, both of which could 

appear on the middle bajada in the Avra Valley 

area of the district. There is a single museum 

record of the canyon treefrog (Hyla arenicolor) 

from the Santa Cruz River east of the district, 

and this species could be present in the district, 

even though the river is very poor habitat for this 

Sample period

0 10 20 30 40 50 60

Cumultive number of species

5

10

15

20

25

30

35

40

Species accumulation curve

Number of species observed

Figure 4.3. Species accumulation curve for herpetofauna surveys, all methods combined, Saguaro NP, 

Tucson Mountain District, 2001 and 2002. Each sampling period represents batches of 33 individuals, the 

mean number of individuals observed in an 8-hour field day. Cumulative number of species
33

frog, and the district probably has at best limited 

marginal habitat. The non-native American 

bullfrog (Rana catesbeiana) and checkered garter 

snake are currently in the Santa Cruz River, 

and migrants of both could reach the district 

occasionally, though they would not find suitable 

habitat there.

A look at the species accumulation curves 

shows they are nearly asymptotic for all survey 

methods (Fig. 4.3). When selection of sampling 

periods was not randomized, however, no new 

species were detected during intensive surveys in 

the last 25% of sampling, whereas for extensive 

surveys, species richness increased by 16.7% (5 

species) during the last 25% of sampling (Fig. 

4.4). 

Discussion

Abundance and distribution

The Tucson Mountain District of Saguaro 

National Park has a relatively well-studied 

herpetofauna compared to other areas, due 

mainly to its location in close proximity of 

Tucson. However, our study is the first to 

quantify relative abundance and distribution of 

amphibians and reptiles and to evaluate patterns 

of these parameters in space and time. Further, 

this inventory represents the first comprehensive 

effort to document species presence throughout 

the district and is a baseline for evaluating future 

changes in the herpetological community there. 

Many of the patterns that we saw in 

distribution and abundance of herpetofauna 

confirm patterns observed in previous studies. 

The far greater number of diurnal lizards 

detected on both intensive and extensive surveys 

compared to snakes and amphibians is typical of 

species inventories in the southwestern United 

States (e.g., Turner et al. 2003, Swann 1999, 

Swann et al. 2000, Swann and Schwalbe 2001). 

Most snakes are nocturnal and spend a great 

deal of time underground, while toads are active 

almost exclusively at night during the summer 

rainy season, which was clearly evidenced by 

the large increase in the number of toads we 

detected with rising humidity. Western whiptails 

and zebra-tailed lizards, the most frequently 

encountered species on our surveys, are very 

common in desert environments in the Tucson 

area. The major shifts in abundance of two other 

common lizards, side-blotched and tree lizards, 

is also typical, with tree lizards more typically 

active in spring, and side-blotched lizards more 

active in late summer (Goode et al. 2004). 

With some exceptions, we found that 

abundance and species richness of both lizards 

and snakes was higher on the bajada than in the 

Sample bin

0 20 40 60 80

Cumultive number of species

0

5

10

15

20

25

30

35

Extensive surveys

Intensive surveys

Road surveys

Figure 4.4. Species accumulation curve for herpetofauna surveys, by survey type, Saguaro NP, Tucson 

Mountain District, 2001 and 2002. Each sampling bin for extensive and intensive surveys represents batches of 

11 individuals, and the sampling bin for road transects represents two individuals. Cumulative number of species
34

mountains or the transition zone between them 

(Table 4.5). This relationship has been observed 

by herpetologists in the field but has not been 

well documented, and the reasons are not well 

understood. It seems possible that loose desert 

soils are better suited for digging and therefore 

allow for creation of underground structure, 

primarily by mammals, which provides protection 

for both reptiles and their prey. It is also possible 

that sandy desert soils support a greater density of 

plant foods and therefore a greater abundance of 

prey. 

Study design

Our major goal for the herpetological inventory 

was to meet the multiple requirements of 

using a study design that was repeatable and 

allowed inference to the whole district, while 

also detecting the maximum number of species 

and being efficient in terms of field effort. In 

general we achieved these goals, but clearly 

some methods were more effective than others. 

Extensive surveys detected more species (30) 

than other methods, in part because more time 

was spent using this method and areas were 

surveyed in both day and night. However, this 

method did not detect as many individuals per 

unit effort as other methods and failed to detect 

six species known to occur in the district. In 

contrast, intensive surveys detected only 14 

species but resulted in the greatest number of 

individuals observed per unit effort. 

It is probable that differences in both 

abundance and richness results for the two 

methods are due to intensive surveys being 

conducted during the day, whereas many 

extensive surveys were conducted in the late 

afternoon and at night. Thus, intensive surveys 

focused on lizards, which are abundant and 

diurnal, while extensive surveys focused on 

both lizards and snakes, which tend to be more 

nocturnal and less abundant. In addition, 

intensive surveys were conducted in areas that 

were randomly located (and only very steep areas 

were excluded), and extensive surveys covered 

all areas of the district and were not randomly 

selected. For future surveys, an alternative design 

might be to combine the best of both intensive 

and extensive surveys; to establish both day and 

night sampling periods, and to establish plots 

based on a stratified design that either uses larger 

blocks (as in extensive surveys) or includes as 

strata features that are specific for herpetofauna, 

such as washes with high concentrations of 

caliche caves, wet areas and seeps, and low-lying 

areas that flood during summer rains. 

For both pitfall trapping and road surveys, 

we would have detected more species with 

greater survey effort. However, pitfall trapping 

is probably not a good method for most of the 

district due to extremely hard soils and significant 

archaeological resources, which makes building 

trap arrays prohibitive. In addition, high daytime temperatures limit the number of traps 

that can be maintained. Road surveys can be 

extremely effective in detecting amphibians, 

but any method for sampling amphibians in the 

Sonoran Desert relies critically on timing: being 

present during summer evenings when rain is 

falling. Because summer rains are rare and 

unpredictable, adequate sampling for amphibians 

is nearly always difficult to achieve, especially 

for inventories such as ours that are of short 

duration. Because of this, it is important that 

park staff go out during rain events, because there 

is potential for detecting species that may occur 

in the district but are very rare. Road surveys 

also remain one of the most effective methods for 

detecting rare snakes and for collecting voucher 

specimens from road kill. 

Management Issues

Our survey did not detect any species that 

were federally threatened or endangered. The 

Sonoran Desert population of the desert tortoise 

is currently being petitioned for federal listing, 

and the park has both a past inventory (Wirt 

and Robichaux 2001) and current monitoring 

plans for this species. The Tucson shovel-nosed 

snake, a candidate for federal listing, was not 

encountered during our inventory but may occur 

in the district.

In general, we suspect that the district has 

a relatively healthy herpetofauna. A possible 

exception is loss of valley-bottom species on 

the west side of the district that were never 

documented, and the unexplained absence of the 

saddled leaf-nosed snake and its early decline 
35

along the Santa Cruz River. There is little 

evidence that the district had greater surface 

water historically, and so aquatic species were 

probably never established. Similarly, there 

is little evidence that exotic species (reptiles, 

amphibians, mammals, or birds) are having an 

impact on reptiles and amphibians. If spinytailed iguanas and Mediterranean geckos were 

capable of establishing themselves in the district 

they probably would have already done so. 

Currently, the greatest threats to 

herpetofauna include illegal collecting, mortality 

due to vehicles (roadkill) in bajada areas of high 

species richness, urban threats such as introduced 

diseases, and potential loss of species due to loss 

of habitat outside the district. Reptile poaching 

clearly occurs in the district, and law enforcement 

rangers are working closely with other agencies 

to combat this problem (Robert Stinson, Tucson 

Mountain District Ranger, pers. comm.). 

Roadkill is a well-documented issue; park staff 

estimate that literally thousands of reptiles and 

amphibians are killed in the district by cars 

each year (Kline and Swann 1998). Exotic 

diseases, such as upper respiratory tract disease 

may affect desert tortoises (Jones et al. 2005), 

and monitoring their health, here as well as 

throughout the species’ range, remains important. 

Each of these issues has the potential to impact 

rare species such as sidewinders and long-lived 

species like desert tortoises and could reduce 

species richness over time. 

Habitat loss and fragmentation outside 

the district are probably the major problems 

for species that occur in the district, but are at 

the edge of their range. The Central Arizona 

Project canal and major roads such as Sandario 

and Picture Rocks Roads are major barriers for 

movement of individuals between the district and 

other areas. If species are lost from the district 

in the next few decades, we predict that it will be 

species on the west side of the Tucson Mountains 

such as sidewinders and desert iguanas. It 

seems possible that, for the same reason, a few 

species that occurred in the past have already 

been lost. In a presentation to the Symposium 

on Research in Saguaro National Monument in 

1991, the eminent herpetologist Charles H. Lowe 

bemoaned the development of Avra Valley and 

the fact that it was not protected by the National 

Park Service: 

“Saguaro National Monument 

(SNM) could have included a 

representative portion of the 

historically and biologically 

significant Avra Valley within its 

boundaries with relative ease 50-

60 years ago, perhaps even 30-40 

years ago. The then essentially 

pristine and little known area 

of Avra Valley that lies directly 

below the western boundary 

fence of SNM has since become 

variously occupied, and is now 

largely destroyed...But such 

thinking today is with the clarity 

of hindsight in a much more 

knowledgeable world. The 

problem in the early 1930s was 

ecological. Ecology was then a 

young and little-known science, 

and a fully coherent concept 

of the ecosystem much less the 

Sonoran Desert, was not at hand. 

The problem later in the 1960s 

was political; it was too late.” 
36
37

Previous Research

Prior to our work, there had been no 

comprehensive and well-documented bird 

inventory for the Tucson Mountain District of 

Saguaro National Park. Monson and Smith 

(1985) compiled a checklist, but there is no 

documentation for the list, though it was probably 

based on limited observations in the district. 

The list includes abundance categories and this 

information was likely based on Gale Monson’s 

extensive knowledge of the distribution and 

relative abundance of birds in similar areas 

in the region. Yensen (1973) studied bird 

communities at four sites on the west side of 

the Tucson Mountains. The Arizona Game and 

Fish Department surveyed for breeding birds 

in one Breeding Bird Atlas block (Avra Valley) 

on the west side of the district (Short 1996). 

Those results are reported in Corman and WiseGuervais (2005). There was a Breeding Bird 

Survey route approximately 25 km northwest 

of the district in the Avra Valley which was 

surveyed from 1992 to 2002 (Sauer et al. 2005). 

The Tucson Bird Count has conducted counts 

along the eastern edge of the district (TBC 2005). 

Mannan and Bibles (1989) studied the impact 

of non-native species on native cavity-nesting 

species. Single species studies have included 

the purple martin (Stutchbury 1991) and elf 

owl (Bob Steidl, unpubl. data). Park personnel 

survey periodically for the cactus ferruginous 

pygmy-owl and park staff file annual reports on 

monitoring and relevant management activities 

related to this species to the U.S. Fish and 

Wildlife Service (Saguaro NP, unpubl. reports).

Methods

We surveyed for birds at the Tucson Mountain 

District from 2001 to 2002 using three field 

methods: variable circular-plot (VCP) counts 

for diurnal breeding birds, nocturnal surveys 

for owls, and incidental observations for all 

birds. We concentrated our survey effort during 

the breeding season because bird distribution 

is relatively uniform in that season due to 

territoriality among most landbird species (Bibby 

et al. 2002), and this uniformity increased our 

precision in estimating relative abundance and 

also enabled us to document breeding activity. 

Our survey period included peak spring migration 

times for most species, which added many 

migratory species to our list.

Spatial Sampling Designs

We established random study sites as described 

in Chapter 1. We established the locations of 

all other surveys (i.e., reconnaissance VCP and 

nocturnal surveys) subjectively in areas that we 

believed would have the highest species richness 

or as a matter of convenience (Fig. 5.1).

Variable Circular-plot Surveys 

Field Methods

We used the variable circular-plot (VCP) method 

to survey for diurnally active birds during the 

breeding season (Reynolds et al. 1980, Buckland 

et al. 2001). Conceptually, these surveys are 

similar to traditional “point counts” (Ralph et. 

al 1995) during which an observer spends a 

standardized length of time at one location (i.e., 

station) and records all birds seen or heard and 

the distance to each bird or group of birds. 

Each station within a transect was 

located a minimum of 250 m apart to maintain 

independence among observations. On 

each successive visit to a transect (except 

reconnaissance transects) we alternated the order 

in which we surveyed stations to minimize bias 

by observer, time of day, and direction of travel. 

We did not survey when wind exceeded 15 km/h 

or when precipitation exceeded an intermittent 

drizzle. We attempted to begin surveys 

approximately 30 minutes before sunrise and 

conclude surveys no later than three hours after 

sunrise. 

We used two variations of the standard 

VCP surveys. These methods differed only 

in number of visits (repeat-visit transects that 

were either random or non-random transects 

and reconnaissance VCP surveys that were all 

random) (Table 5.1). We revisited most survey 

stations multiple times to get better estimates of 

Chapter 5: Birds

Brian F. Powell
38

the species present at each site and their relative 

abundances. Although most of the survey effort 

was focused on repeat-visit transects, this left 

large areas of the district unsurveyed. Therefore, 

to get better spatial coverage of the district we 

established four reconnaissance transects (Fig. 

5.1). 

We recorded a number of environmental 

variables at the beginning of each transect: wind 

speed (Beaufort scale), presence and severity 

of rain (qualitative assessment), air temperature 

(oF), relative humidity (%), and cloud cover 

(%). After arriving at a station, we waited one 

minute before beginning the count to allow birds 

to resume their normal activities. We identified 

to species all birds seen or heard during an eightminute “active” period (for reconnaissance VCP 

surveys we spent five minutes at each station 

to cover as much area as possible). For each 

detection we recorded the distance (in meters) the 

bird was from the observer (measured with laser 

range finder when possible), time of detection 

(measured in one-minute intervals beginning 

at the start of the active period), and the sex 

Figure 5.1. Location of VCP and nocturnal survey stations for birds, Saguaro NP, Tucson Mountain 

District, 2001 and 2002.
39

and/or age class (adult or juvenile), if known. 

We did not measure distances to birds that were 

flying overhead nor did we use techniques to 

attract birds (e.g., “pishing”). We made an effort 

to avoid double-counting individuals. If we 

observed a species during the “passive” count 

period (between the eight-minute counts) which 

had not been recorded previously at a station on 

that visit, we recorded its distance to the nearest 

station.

Effort

We surveyed at five random transects in 2001 

(Table 5.1). Each transect had four stations 

(except number 238 which had one additional 

non-random transect in King’s Canyon) and 

we surveyed at each transect four times. We 

completed reconnaissance VCP surveys for four 

transects in 2002. The number of stations along 

reconnaissance transects varied from two to five. 

Analysis

We calculated relative abundance of each species 

along each transect as the number of detections 

at all stations and visits (including zero values) 

and divided by effort (total number of visits 

multiplied by total number of stations). We 

reduced our full collection of observations for 

each repeat-visit VCP station to a subset of data 

that was more appropriate for estimating relative 

abundance. We used only those detections that 

occurred ≤ 75 m from count stations because 

detectability is influenced by conspicuousness 

of birds (i.e., loud, large, or colorful species are 

more detectable than others) and environmental 

conditions (dense vegetation can reduce 

likelihood of some detections). Truncating 

detections may reduce the influence of these 

factors (Verner and Ritter 1983; for a review of 

factors influencing detectability see Anderson 

2001, Pollock et al. 2002). We also excluded 

observations of birds that were flying over the 

station, birds observed outside of the eightminute count period, and unknown species. 

Some observations met more than one of these 

criteria for exclusion from analysis. We report 

the relative abundance by repeat-visit transect and 

year. Because relative abundance is the closest 

index to true population size that we employ (see 

Chapter 1 for more detailed discussion), we use it 

to note the “abundance” of species. 

Nocturnal Surveys

Field Methods

To survey for owls we broadcast commercially 

available vocalizations (Colver et al. 1999), using 

a compact disc player and broadcaster (Bibby et 

al. 2002), and recorded other nocturnal species 

(nighthawks and poorwills) when observed. We 

established two transects (Fig. 5.1) and spaced 

stations with transects a minimum of 500 m 

Table 5.1. Summary of bird survey effort by UA inventory personnel, Saguaro NP, Tucson 

Mountain District, 2001 and 2002. Sample size was used in calculating relative abundance for each 

transect and each year. 

Years

2001 2002

Survey type Transect name

Number of

stations in transect Visits n Visits n

Repeat-visit VCP 204 4 5 20

212 5a 4 20

213 4 4 16

238 4 4 16

239 4 4 16

Reconnaissance VCP Bajada 2 1 2

Camino De Cerro Wash 3 1 3

Picture Rocks Wash 5 1 5

Vicinity Random 239 3 1 3

Nocturnal Golden Gate 6 3 18 2 12

Loop Road 6 3 18 1 6

a Includes one station in King’s Canyon that was non-randomly selected.
40

apart. We attempted to reduce sampling biases 

by varying direction of travel along transects and 

by not surveying during periods of excessive rain 

or wind. We began surveys approximately 45 

minutes after sunset. We began surveys at each 

station with a three-minute “passive” listening 

period during which time we broadcast no calls. 

We then broadcast vocalizations for a series 

of two-minute “active” periods. We broadcast 

vocalizations of species that we suspected 

might be present, based on habitat and range 

information: elf, western screech, burrowing, 

and barn owls. We excluded the great horned 

owl from the broadcast sequence because of its 

aggressive behavior toward other owls. Also, we 

did not survey for cactus ferruginous pygmy owls 

because that would have required use of specific 

protocols and because park staff survey annually 

for them. 

We broadcast recordings of owls in 

sequence of species size, from smallest to largest 

size species, so that smaller species would not be 

inhibited by the “presence” of larger predators or 

competitors (Fuller and Mosher 1987). During 

active periods, we broadcast owl vocalizations 

for 30 seconds followed by a 30-second listening 

period. This pattern was repeated two times 

for each species. During the count period we 

used a flashlight to scan nearby vegetation and 

structures for visual detections. If we observed 

a bird during the three-minute passive period, 

we recorded the minute of the passive period in 

which the bird was first observed, the type of 

detection (aural, visual, or both), and the distance 

to the bird. If a bird was observed during any of 

the two-minute active periods, we recorded in 

which interval(s) it was detected and the type of 

detection (aural, visual, or both). As with VCP 

surveys we attempted to avoid double-counting 

individuals recorded at previous stations. We 

also attempted to use a different observer for each 

visit, alternate direction of travel along transects, 

and not survey during inclement weather. 

Effort

We surveyed two transects in the district. Each 

transect had six stations that we surveyed at least 

four times each (Table 5.1). 

Analysis

We calculated relative abundance as per VCP 

surveys. 

Community-type Identification

We sought to identify bird/vegetation 

communities within the district and to compare 

characteristics among them. To group transects, 

we used Ward’s hierarchical cluster analysis 

using data from point-intercept transects. Cluster 

analysis is a multivariate technique that groups 

like entities (in our case transects) that share 

similar values. We used the total number of point 

intercepts by the most common plant species in 

all four height categories for this analysis. 

Incidental and Breeding Observations 

Field Methods

When we were not conducting formal surveys 

and we encountered a rare species, a species in 

an unusual location, or an individual engaged 

in breeding behavior, we recorded UTM 

coordinates, time of detection, and (if known) 

the sex and age class of the bird. We recorded 

all breeding observations using the standardized 

classification system developed by the North 

American Ornithological Atlas Committee 

(NAOAC 1990), which characterizes breeding 

behavior into one of nine categories: nest 

building, occupied nest, used nest, adult carrying 

nesting material, adult carrying food or fecal sac, 

adult feeding young, adult performing distraction 

display, or fledged young. We made breeding 

observations during standardized surveys and 

incidental observations. 

Analysis

We report frequency counts of incidental and 

breeding observations.

Results

We made 2,142 observations representing 73 

species in 2001 and 2002 (Appendix C). We 

found five species that had not been recorded 

for the district: great-tailed grackle, northern 

rough-winged swallow, cliff swallow, broadtailed hummingbird, and blue grosbeak. None 

of the species were particular surprising and 
41

Table 5.2. Total number of observations (sum) and relative abundance (mean + SE), by transect, of birds 

recorded during repeat-visit VCP surveys, Saguaro NP, Tucson Mountain District, 2001 and 2002. Total number 

of observations includes those observations excluded from relative abundance estimates. 

239 238 213 212 204

Species Sum Mean SE Sum Mean SE Sum Mean SE Sum Mean SE Sum Mean SE

Gambel’s quail 33 0.13 0.085 5 20 0.25 0.144 17 0.2 0.117 32 0.25 0.099

turkey vulture 5 3 1

Harris’s hawk 8 0.06 0.063

red-tailed hawk 1 4

golden eagle 3

American kestrel 3 2

prairie falcon 10

white-winged dove 28 0.25 0.112 20 0.19 0.101 29 0.44 0.157 40 0.55 0.24 49 0.35 0.109

mourning dove 44 0.94 0.249 22 0.75 0.250 23 0.25 0.112 40 0.50 0.185 51 0.80 0.200

Inca dove 1

common poorwill 1

white-throated swift 36

black-chinned hummingbird 1

Costa’s hummingbird 5 0.19 0.101 4 1 0.05 0.050

Gila woodpecker 53 0.69 0.285 40 0.50 0.183 69 1.75 0.348 42 0.25 0.143 84 1.55 0.246

ladder-backed woodpecker 2 3 0.06 0.063 2 0.1 0.069 2

gilded flicker 1 7 0.19 0.136 10 0.31 0.151 7 0.1 0.069 10 0.05 0.050

gray flycatcher 1

ash-throated flycatcher 20 0.56 0.258 28 0.06 0.063 22 0.38 0.180 32 0.35 0.131 21 0.30 0.128

brown-crested flycatcher 3 0.13 0.085 3 0.13 0.085 7 0.2 0.117 8 0.25 0.123

western kingbird 1 0.05 0.050

western scrub-jay 1

common raven 2 12 1

purple martin 9 14 0.05 0.050

cliff swallow 1

verdin 28 1.06 0.193 14 0.69 0.151 28 1.50 0.158 21 0.75 0.143 37 1.55 0.135

cactus wren 34 1.44 0.203 27 0.88 0.202 25 1.13 0.221 22 0.60 0.152 41 1.10 0.176

rock wren 4 3 0.1 0.069 1

canyon wren 24 0.13 0.085 3 0.06 0.063 13 0.2 0.092

blue-gray gnatcatcher 1

black-tailed gnatcatcher 10 0.50 0.158 12 0.69 0.176 12 0.50 0.158 10 0.40 0.169 18 0.60 0.152

northern mockingbird 2 4

Bendire’s thrasher 1

curve-billed thrasher 34 0.88 0.221 15 0.06 0.063 16 0.56 0.182 3 20 0.45 0.114

phainopepla 1 2

orange-crowned warbler 2 0.10 0.100

Lucy’s warbler 1

black-throated gray warbler 1

green-tailed towhee 1 2 0.05 0.050

canyon towhee 4 0.25 0.112 12 0.50 0.158 5 0.13 0.085 14 0.30 0.147 18 0.35 0.131

rufous-winged sparrow 11 0.31 0.120 3 0.10 0.069

rufous-crowned sparrow 1 0.05 0.050 5 0.05 0.050

chipping sparrow 2

Brewer’s sparrow 16 0.31 0.176 2 0.05 0.050 3 0.10 0.069

black-throated sparrow 1 0.06 0.063 37 1.63 0.473 13 0.56 0.203 28 0.80 0.186 12 0.35 0.109

white-crowned sparrow 2 0.10 0.100 1

northern cardinal 1 0.06 0.063 3 0.15 0.082 3 0.10 0.069

pyrrhuloxia 4 0.06 0.063 1 28 0.69 0.198 11 0.10 0.100 16 0.35 0.109

black-headed grosbeak 1 0.05 0.050

lazuli bunting 1 0.05 0.050

varied bunting 3

great-tailed grackle 3

brown-headed cowbird 9 0.06 0.063 21 0.38 0.221 11 0.25 0.112 11 0.25 0.143 17 0.15 0.109

Bullock’s oriole 1 2 1

Scott’s oriole 6 2 2 1

house finch 10 0.25 0.144 8 0.13 0.085 17 0.25 0.112 25 0.30 0.147 9 0.20 0.156

lesser goldfinch 1 2 4 0.05 0.050
42

were likely overlooked by previous researchers. 

All of the species that we observed with species 

conservation designations were fairly common 

in the district: elf owl, Gila woodpecker, gilded 

flicker, Costa’s hummingbird, purple martin, 

Lucy’s warbler, and rufous-winged sparrow. The 

most interesting observation was of an active nest 

of a prairie falcon, which was located only about 

20 m away from an active golden eagle nest. 

VCP Surveys

We recorded 63 species during surveys at 

repeat-visit (n = 58 species; Table 5.2) and 

reconnaissance (n = 31 species) VCP surveys 

(Table 5.3, Appendix C). We found 13 species 

at all five repeat-visit VCP transects, and most of 

these species were the most abundant species at 

each transect (Table 5.2). Two of the three most 

abundant species on all transects were the verdin 

and cactus wren. Other widespread and abundant 

species included the white-winged and mourning 

doves, Gila woodpecker, ash-throated flycatcher, 

and black-throated sparrow. Many species were 

not as abundant but had very consistent relative 

abundance estimates among transects: blacktailed gnatcatcher, canyon towhee, brown-headed 

cowbird, and house finch. The phyrroloxia 

and curve-billed thrasher were two widespread 

species that had very different inter-transect 

abundance estimates (Table 5.2). 

Despite some inter-transect differences 

in species composition and relative abundance 

estimates, we found no logical grouping of 

transects based on either the plant or the bird data 

from cluster analysis. This is most likely because 

many of the most common bird and plant species 

were found in all transects (see above). Similarly, 

we found no vegetation characteristics that 

predicted differences in observed species richness 

among transects using stepwise multiple linear 

regression. 

We observed 31 species during 

reconnaissance VCP surveys, including six 

species that we did not observe on repeat-visit 

surveys: greater roadrunner, lesser nighthawk, 

Anna’s hummingbird, northern rough-winged 

Table 5.3. Mean relative abundance of birds from reconnaissance VCP surveys, Saguaro NP, Tucson Mountain 

District, 2002. 

Bajada 

(n = 2)

Camino del 

Cerro (n = 3)

Picture Rocks 

(n = 5)

Vicinity 239 

(n = 3)

Species Sum Mean SE Sum Mean SE Sum Mean SE Sum Mean SE

Gambel’s quail 3 1.50 0.500 1 0.20 0.200

white-winged dove 1 0.50 0.500 1 0.33 0.333 4 0.80 0.200

mourning dove 1 0.33 0.333

Anna’s hummingbird 1 0.33 0.333

Gila woodpecker 2 1.00 1.000 3 1.00 0.000 3 0.60 0.245 2 0.67 0.333

gilded flicker 1 0.33 0.333

ash-throated flycatcher 1 0.50 0.500 1 0.33 0.333 1 0.20 0.200

brown-crested flycatcher 4 1.33 0.667

verdin 3 1.50 0.500 1 0.33 0.333 5 1.00 0.548 1 0.33 0.333

cactus wren 4 2.00 1.000 1 0.33 0.333 3 0.60 0.245 4 1.33 0.333

blue-gray gnatcatcher 1 0.20 0.200 1 0.33 0.333

black-tailed gnatcatcher 2 0.40 0.245

curve-billed thrasher 2 1.00 1.000 2 0.67 0.333 2 0.40 0.245 3 1.00 0.000

Wilson’s warbler 2 0.67 0.667

green-tailed towhee 1 0.20 0.200

canyon towhee 2 0.67 0.667 1 0.20 0.200

black-throated sparrow 1 0.33 0.333 2 0.40 0.400

pyrrhuloxia 1 0.50 0.500 2 0.67 0.333 2 0.40 0.400 1 0.33 0.333

blue grosbeak 1 0.20 0.200

brown-headed cowbird 2 0.67 0.667 1 0.20 0.200

Scott’s oriole 1 0.33 0.333

house finch 1 0.50 0.500 4 0.80 0.583 1 0.33 0.333
43

swallow, Wilson’s warbler, and blue grosbeak 

(Table 5.3). Although sample sizes were 

too small to make meaningful comparisons 

among transects, there were similar patterns of 

abundance for some of the most widespread 

species such as verdin, cactus wren, and Gila 

woodpecker. 

Nocturnal Surveys

We found three species of owls, the lesser 

nighthawk, and the common poorwill on 

both nocturnal transects (Table 5.4). Relative 

abundance estimates were similar between 

transects for all species except the western 

screech-owl, which was most abundant on the 

Golden Gate Loop transect. The elf owl was the 

most common species on both transects.

Incidental and Breeding Observations

We made incidental observations of 47 species 

including six species that had not been observed 

during other survey methods (Appendix C). We 

made 37 breeding behavior observations of 17 

species (Table 5.5). 

Inventory Completeness

The inventory of birds at the district is likely 

close to completion. Our effort, however, was 

insufficient to document even 90% of the species 

that have been recorded for the district; the 

species accumulation curve (Fig. 5.2) showed 

little sign of leveling off despite over 2,000 

observations of birds. Given the low species 

richness of birds in the district (Appendix C), this 

Table 5.4. Mean relative abundance of birds, by transect, from nocturnal surveys, 

Saguaro NP, Tucson Mountain District, 2001 and 2002. 

Golden Gate Loop Loop Road

Species Sum Mean SE Sum Mean SE

western screech-owl 14 0.47 0.11 4 0.17 0.08

great horned owl 2 0.07 0.05 2 0.08 0.06

elf owl 34 1.13 0.22 24 1.00 0.22

lesser nighthawk 7 0.23 0.17 8 0.33 0.14

common poorwill 16 0.53 0.13 10 0.42 0.15

Table 5.5. Number of observations for each breeding behavior for birds, Saguaro NP, Tucson Mountain 

District, 2001 and 2002. Breeding behaviors follow standards set by NAOAC (1990). 

Nest Adults carrying Feeding 

recently 

fledged 

young

Recently 

fledged 

Species young

BuildingWith 

eggs

With 

young

Occupied FoodNesting 

material

Distraction 

displays Totals

prairie falcon 1 1 2

golden eagle 1 1

white-winged dove 3 3

mourning dove 1 1

Costa’s hummingbird 1 2 3

Gila woodpecker 2 4 6

gilded flicker 1 1

ash-throated flycatcher 1 1 2

common raven 1 1

verdin 2 1 3

cactus wren 1 1

canyon wren 1 1

black-tailed gnatcatcher 1 1

curve-billed thrasher 1 2 3

black-throated sparrow 1 5 6

pyrrhuloxia 1 1

varied bunting 1 1

Totals 5 5 11 4 1 3 2 6 37
44

result was surprising, but is probably explained 

by the relatively high percentage of passage 

migrant species compared to the number of 

resident or breeding species. Although our effort 

was not sufficient to document at least 90% of 

the species thought to occur in the district, we 

believe that we accounted for almost all of the 

species that are thought to be resident or breeding 

species. By combining our effort with others 

(summarized in Appendix C), the species list for 

the district is likely 90% complete. 

Discussion

The species richness at the district is 

unremarkable when compared to other areas of 

the region. Species typical of the Sonoran desert 

uplands, such as the white-winged dove, Gila 

woodpecker, verdin, cactus wren, and curvebilled thrasher were widespread and abundant 

throughout the district. The district also hosts 

some migratory and overwintering species 

common in the spring including: green-tailed 

towhee, ruby-crowned kinglet, and blue-gray 

gnatcatcher. 

The low number of species in the district 

is not surprising; Sonoran desert scrub does not 

have high species richness (Tomoff 1974). The 

low number of species in the district is also 

not surprising given the lack of mesic riparian 

vegetation (e.g., Fremont cottonwood, Arizona 

sycamore, and netleaf hackberry), which has the 

highest species richness in the region (Strong and 

Bock 1990). Even areas with dense assemblages 

of xeric riparian vegetation (e.g., mesquite and 

palo verde) in southern Arizona have a high 

number of species, especially spring passage 

migrants (Hardy et al. 2004). The Tucson 

Mountain District has no mesic and few areas 

of well-developed xeric riparian vegetation, so 

it was not surprising that we found only a few 

migratory species and very few individuals of 

xeric riparian-obligate birds (e.g., Lucy’s warbler 

and varied bunting). Nevertheless, many of the 

species that are common to the Sonoran Desert 

uplands are species of management concern 

because their global distribution is largely 

restricted to the desert southwest and adjacent 

Mexico (Latta et al. 1999). Increased conversion 

of these areas to housing and other forms of 

development may severely impact these bird 

communities, making refugia such as the Tucson 

Mountain District all the more important. 

The district’s bird community has 

surprisingly few individuals of non-native 

Sample period

0 10 20 30 40

Cumulative number of species

20

40

60

80

Figure 5.2. Species accumulation curve for birds, all survey methods, Saguaro 

NP, Tucson Mountain District, 2001 and 2002. Each sample period is a randomized 

combination of approximately 50 observations (N = 2,142). 
45

or human-adapted species (e.g., great-tailed 

grackle, European starling, house sparrow; 

Table 5.2). These species are usually abundant 

in and around development (Mills et al. 1989, 

Germaine et al. 1998) and we observed them in 

areas of the district that were adjacent to housing 

development, particularly on the west side of 

the district. An increase in these human-adapted 

species is likely with increasing development 

in the Picture Rocks area. All three non-native 

species (rock pigeon, European starling, and 

house sparrow) will likely reach their highest 

densities in lands directly adjacent to the district, 

but only the starling is likely to have impacts 

further in the from the boundary; they are known 

to travel great distances between nest sites 

(primarily saguaro cavities) and foraging areas, 

particularly around lawns and horse facilities. 

Mannan and Bibles (1989) assessed the potential 

for competition for nesting sites between native 

and non-native cavity-nesting species and 

concluded that there was little cause for concern 

in both districts of the park. They cited an 

abundance of available cavities and few sightings 

of direct competition between native and nonnative species. 

An increase in housing and other 

development adjacent to the district may facilitate 

the spread of non-native plants and animals, 

which can impact the native bird community. 

Non-native plants that alter fire regimes (e.g., 

buffelgrass) may ultimately impact the bird 

community because of changes to the plant 

community that result from fire. These losses 

include many of the cacti, such as saguaros, 

that are important food and nesting sites for 

many birds. Non-native pets are also a concern, 

particularly free-roaming feral cats, which kill 

and harass birds (Clarke and Pacin 2002). 

Unlike the significant changes that have 

taken place to the bird community on the Rincon 

Mountain District (Powell et al. 2006), we 

do not believe there have been recent species 

extirpations in the Tucson Mountain District, 

though there are no historical data with which 

to compare. A few species of note included a 

single observation of Bendire’s thrasher despite a 

concerted effort to find it. This species has likely 

undergone population declines in the vicinity 

of Tucson (Tom Huels, pers. comm.). We also 

expected to find a few Bell’s vireo and perhaps 

Abert’s towhee in some of the xeroriparian 

washes but could not locate them. They remain 

on the district’s list because of observations by 

Yensen (1973) and Monson and Smith (1985). 

 
46
47

Previous and Ongoing Research 

Prior to our effort, Saguaro National Park 

had never had a comprehensive survey of its 

mammals. There have been several studies on 

mammals, but mostly in the Rincon Mountain 

District (summarized in Swann and Powell 

2006b). Notable exceptions in Tucson Mountain 

District include an inventory of bats by Sidner 

and Davis (1994), part of a PhD study of rodents 

by Yensen (1973), part of a PhD study by 

M’Closkey (1980), and a long-term monitoring 

plot for rodents, established by Robert Parmenter, 

that was first trapped in 1991 and adopted by park 

biologists in 2004 (Parmenter, unpubl. data). In 

addition, there have been surveys for species of 

management interest, including mule deer and 

kit foxes associated with the Central Arizona 

Project (CAP) in the 1980s (deVos et al. 1983), 

and subsequent monitoring of water catchments 

intended to mitigate the effects of the CAP (Kline 

et al. 1998). Other relevant work includes recent 

monitoring of bats associated with mines (Dalton 

and Wolf 2002, Wolf and Dalton 2003) and 

surveys for mountain lions and bobcats (Hackl 

et al. 2006, Haynes et al. 2007). Finally, TMD 

was the site for a series of studies of collared 

peccary during the 1960s and 1970s by wildlife 

students from the University of Arizona (e.g., 

Schweinsburg 1971). 

Saguaro National Park has also been 

collecting observations of wildlife for several 

decades. Most of these sightings, while not 100% 

reliable, have been entered into a database and 

mapped in a GIS and are available in an appendix 

to this report (available at the park and I&M 

office in Tucson). In Saguaro’s administrative 

records at the Western Archaeological and 

Conservation Center there is a limited amount 

of information on mammals from the Tucson 

Mountain Park in the 1930s, when NPS assisted 

Pima County in management of the park, and in 

the 1960s, after TMD was established. 

Methods 

We surveyed for mammals using four field 

methods: (1) trapping for rodents and ground 

squirrels (primarily nocturnal; herein referred 

to collectively as small mammals), (2) infraredtriggered photography for medium and large 

mammals, (3) netting for bats, and (4) incidental 

observations for all mammals (Figs. 6.1, 6.2) 

We established a pitfall array for reptiles and 

amphibians (see Chapter 4) but captured very few 

mammals. The infrared-triggered photography 

survey was a collaborative effort and most of 

the field survey effort was carried out by park 

biologists. Two previous reports use a subset 

of the data presented here. Dee et al. (2002) 

compared species richness based on infraredtriggered photography and mitochondrial DNA 

extracted from animal scat. Hackl et al. (2006) 

used photography and DNA analysis based 

on scat to assess status of mountain lions and 

bobcats in the district. 

Small Mammals

Field Methods

We trapped small mammals using Sherman 

live traps (large, folding aluminum, or steel, 3 

x 3.5 x 9”; H. B. Sherman, Inc., Tallahassee, 

FL) set in grids (Figs. 6.3, 6.4). We opened 

and baited traps (one tablespoon: 16 parts 

dried oatmeal to one part peanut butter) in the 

evening, then checked and closed traps the 

following morning. We placed a small amount 

of polyester batting in each trap to prevent trap 

deaths due to cold nighttime temperatures. We 

marked each captured animal with a permanent 

marker to facilitate recognition; these “batch 

marks” appeared to last for the duration of the 

sampling period. For each animal we recorded 

species, sex, age class (adult, subadult, or 

juvenile), reproductive condition, weight, and 

measurements for right hindfoot, tail, ear, head, 

and body. For males we recorded reproductive 

condition as either scrotal or non-reproductive; 

for females we recorded reproductive condition 

as one or more of the following: non-reproducing, 

open pubis, closed pubis, enlarged nipples, small 

or non-present nipples, lactating, post-lactating, 

or non-lactating.

Chapter 6: Mammals

Don E. Swann and Brian F. Powell
48

We were confident in most species 

identifications in the field, with the exception 

of one individual in the genus Peromyscus (see 

Results), and some individuals of rock pocket 

mice and desert pocket mice; both species 

were confirmed, but can be very difficult to 

conclusively distinguish in the field. 

Spatial Sampling Design

The majority of our trapping effort was at focalpoint transects set throughout the district (see 

Chapter 1; Fig. 6.1). We trapped at a subset of 

four random transects (212, 213, 238, and 239) 

that were surveyed for other taxonomic groups. 

Transect 239 was in a bajada area of low slope 

and sandy soils, while the other sites were in 

areas of relatively higher slopes with rocks 

present. We visited transects 213 and 239 twice 

in 2001, with each visit one month apart, and 

visited the other sites only once (Appendix I). 

We also trapped (one visit only) at non-random 

sites in areas that we believed would have high 

species richness: near Kinney Road, and near 

Sandario Road (Fig. 6.1). 

At each random site we established three 

grids (Fig. 6.3) with either a 3x7 or a 5x5 trap 

configuration (Fig. 6.4; Appendix I). Traps set in 

a 3x7 configuration had 16.7 m spacing among 

Figure 6.1. Location of random and non-random small-mammal trapping sites, bat trapping stations, 

and Trailmaster cameras (infrared-triggered cameras), Saguaro NP, Tucson Mountain District, 2001.
49

them and traps in a 5x5 configuration had 12.5 

m spacing among them. Occasionally we also 

placed traps “preferentially”, meaning that traps 

were not set in grids with even spacing, but rather 

in locations that the field crews felt contained 

areas with high species richness. Typically 

these “preferential” sites were near the random 

grids; the crew set out 5 to 70 additional traps 

after setting up the random grids (Appendix 

I). At non-random sites the layout of traps was 

variable, but typically they were in a 5x5 or a 

2x10 configuration. The 2x10 configuration 

was usually along both edges of a wash, because 

we believed that these areas would have more 

animals. 

We always trapped at multiple plots on 

the same night to maximize efficiency. At focal 

points we always trapped all the grids along the 

transect on the same nights and typically trapped 

other, nearby non-random areas. In some nonrandom areas (e.g., Kinney Road) we trapped 

on multiple grids. In this report we summarize 

results by “plot group”, which is the collection 

of trapping grids that represents an area (see 

Appendix I). 

Figure 6.2. Location of infrared-triggered camera units, Saguaro NP, 2002-2005. Includes symbols for 2001 and 

2002 (from Fig. 6.1), non-random points; 2002-2005, random points, and 2002-2005, non-random points. 
50

Effort

We trapped for a total of 1,431 trap-nights (Table 

6.1), all in 2001. In total, we had 521.5 trap 

nights at non-random sites, and 909.5 trap nights 

at random sites. 

Temporal Sampling Design

The total number of nights that we trapped each 

grid was variable, but was typically two or three 

nights per visit (see Appendix I for complete list). 

Occasionally we trapped for as many as four 

nights or as few as one night. Because our goal 

was to maximize the number of individuals and 

species trapped, we varied the number of nights 

trapped based on the trapping results in the first 

few nights of trapping; if we were catching few 

animals, we moved to a different location. 

Analysis

We expressed effort as the number of trap 

nights (number of traps multiplied by number 

of nights they were open) after accounting for 

sprung traps (misfired or occupied; Beauvais and 

Buskirk 1999). Sprung traps reduce trap effort 

because they are no longer “available” to capture 

animals; we account for this by multiplying the 

number of sprung traps by 0.5 (lacking specific 

information, we estimate sprung traps were 

available for half of the night; Nelson and Clark 

1973). We calculated relative abundance for 

species by dividing the number of captures by the 

number of trap nights times 100. For this report 

we calculated relative abundance by plot group, 

type of plot (random or non-random), and visit. 

It is important to note that relative abundance 

1000 m 

focal point 50 m 

50 m 

A

100 m 

Transect

midline 

Smallmammal 

traps 

B

50 m 

Figure 6.3. Layout of small-mammal trapping grids along focal-point transects, Saguaro NP, Tucson 

Mountain District, 2001. See Fig. 6.4 for more details.

Figure 6.4. Detailed layout of small-mammal trapping grids at Saguaro NP, Tucson Mountain District, 2001 and 

2002. We used 3x7 trap grids in 50x100 m plots (A) from mid-April through mid-June and 5x5 trap grids in 50x50 m 

plots (B) from mid-June through October.
51

assumes an equal probability of detections among 

species. Although beyond the scope of this report 

to quantify those differences, it is important 

to recognize that individuals of each species 

react differently to the metal traps. Therefore, 

aside from species-richness estimates, the most 

meaningful comparisons are intra-specific 

differences, both within and among sites. 

Bats

We surveyed for bats using two field methods: 

netting and roost-site investigation. For netting, 

we concentrated our survey effort in areas that 

were most likely to have bats, mostly riparian 

areas with surface water present. We did not 

survey for bats near focal points because of the 

low probability of success in these areas. 

Roosts 

We visited three roosts at TMD (Gould Mine, 

Wild Horse Mine, and Yuma Mine) that were 

known to have bats based on historic records, 

or were likely to have bats based on habitat 

characteristics. At roosts, we observed bats with 

the aid of infrared-filtered light and night-vision 

equipment or red-filtered light. When bats were 

present, we worked quickly to identify them to 

species, but if there were no bats we used bright 

light, then searched for, and collected, skeletal 

material. If there was skeletal material, we 

collected it for later identification. 

Mist Netting

Because most insectivorous bats congregate at 

water sites, we selected two sites (Dobe Wash 

Tank and Javelina Wash Tank) known to have 

reliable surface water (Fig. 6.1). We set mist 

nets directly over water, and varied the number 

of net hours among sites and visits depending 

on field conditions. We used monofilament 

nylon nets of three net sizes (5-m, 9-m, or 12-

m) depending on the site and set nets singly or 

stacked, depending on conditions. For each bat 

captured, we recorded time of capture, species, 

and sex. When appropriate, we also recorded 

reproductive condition, forearm length, mass, 

body condition, tooth wear, presence of parasites, 

and other measurements. We determined whether 

individuals were adult, subadult (by closure of 

epiphyses), or juvenile (by appearance). We 

estimated age by tooth wear. For females, we 

recorded reproductive condition as pregnant 

(palpation for fetal bones), currently lactating 

(mammary gland with milk), previous evidence 

of lactation (misshapen or scarred nipples), or 

nulliparity (non-use of nipples). We determined 

reproductive condition for males by degree 

of swelling of testes or the presence of black 

epididymides and used this information to 

determine if the male was not reproductive, semireproductive, or reproductive. We marked all 

captured bats with a temporary, non-lethal marker 

Table 6.1. Summary of small mammal trapping effort, Saguaro NP, Tucson Mountain District, 2001 and 2002. 

See Appendix I for additional trapping event information. 

Plot group

Site 

characteristics Plot type Visit

Number of 

traps set

Sprung but 

empty traps

Number 

of animals 

captured

Number 

of animals 

recaptured

Number of 

trap nights

212 Rocky slope Non-random 1 40 0 2 0 39.0

Random 1 126 0 8 0 122.0

213 Rocky slope Non-random 1 40 0 4 0 38.0

Random 1 189 8 22 7 170.5

2 150 8 19 2 135.5

238 Rocky slope Random 1 225 9 5 1 217.5

239 Bajada Non-random 1 64 5 22 4 48.5

Random 1 189 1 51 10 158.0

2 150 6 64 18 106.0

Kinney Road Rocky slope Non-random 1 231 5 7 2 224.0

Sendario Road Rocky slope Non-random 1 175 0 5 1 172.0

Total Random 909.5

Non-random 521.5
52

to prevent counting the same individual more 

than once in the same evening. We used sonar 

detectors (Anabat and/or QMC Mini) at all sites 

to aid in determining bat presence/absence and 

relative activity as compared to the visual or mistnet results. We listened passively for the call of 

pallid bats, the only species in the area that can be 

definitively identified by its directive call.

Effort and Analysis

We visited each roost once in 2001 except for 

Gould Mine, which we visited twice, once in 

2001 and once in 2002. We netted bats at two 

sites for a total of 2 nights (41.7 net-hours) in 

2001 (Appendix J). We report the number of 

species and individuals caught at each site. 

Percent netting success was calculated as the 

number of animals caught divided by effort (total 

length of net coverage multiplied by amount of 

time nets were open times 100).

Large and Medium Mammals

Spatial Sampling Design

We used infrared-triggered cameras to detect 

medium and large mammals at a combination of 

random and non-random sites (Fig. 6.1) during 

May 2001 through June 2002, and in a separate 

effort from March 2002 through March 2005 

(Fig. 6.2). During the early effort in 2001 and 

2002 we used cameras at 9 non-random sites; 

because we did not record the dates that these 

photos were taken, in the Results section we 

report these results separately. 

In the later effort, from March 2002 to 

March 2005, we located non-random sites 

primarily at known water sources and game trails, 

but also targeted large holes in the ground, wash 

corridors, and other areas in an effort to detect as 

many species as possible. Location of random 

sites was based on the random coordinates 

chosen as focal points for the plant and animal 

inventories (see Introduction chapter), though 

many of these focal points were not surveyed 

for the other taxonomic groups. To avoid 

interference with other inventory activities at sites 

where there was other inventory work, and to 

maintain consistency among all focal points, we 

offset all camera locations from the focal point 

by using the same coordinates but with the NAD 

27 map datum instead of NAD 83; this moved 

the focal points approximately 200 m from the 

original location. At each random location one 

unit was located at the random point; at selected 

sites we also placed a camera unit at a random 

point located at the nearest measured point in a 

mapped drainage (Dee et al. 2005). 

Temporal design

After setting up a camera unit, we generally 

returned to it one week later to check that it 

was functioning properly and to make repairs 

and change film, if necessary. We then left the 

camera in place for approximately two weeks. 

However, the length of time varied, especially in 

remote areas that required hiking to reach, and we 

left in place a subset of cameras at both random 

and non-random locations for extended periods of 

several months. 

Field methods

We primarily used the Trailmaster camera system 

(model 1500, Goodson and Associates, Inc., 

Lenaxa, KS; Kucera and Barrett 1993). The 

system consists of a transmitter that emits an 

infrared beam, a receiver that detects the beam, 

and a camera that is connected to the receiver 

with a cable (Fig. 6.5). The receiver triggers 

the camera to take a picture when an animal 

breaks the beam. We also used passive infraredtriggered systems, which are triggered by the 

combined heat and movement of an animal, 

including the DeerCam (model DC-100) and 

digital Cuddeback (both from Non-typical, Inc., 

Park Falls, WI) and the CamTrakker (CamTrak 

South,Watkinsville, Ga.). Because they function 

similarly, we do not further differentiate among 

the different camera systems used. 

We initially baited each focal point 

camera using a fish-based canned catfood and a 

commercial trapping lure that attracted predators. 

Generally, we baited with catfood the first 

week, then the trapping lure the second week. 

We occasionally baited non-random camera 

locations. For visitor safety reasons, we did not 

locate baited stations within 100 m of a park trail.

Effort

In addition to the 9 non-random sites during the 

2001 and 2002 effort, we placed cameras at 18 

non-random and 29 random sites throughout the 
53

district (Fig. 6.2). Considering both types of 

camera locations (i.e., random and non-random), 

we placed the majority of cameras in bajada areas 

(characterized as areas with relatively low slopes 

[<10o

]) compared to high slopes (> 10o; Table 

6.2). The total number of camera-nights at all 

sites was approximately 1753, including 1450 in 

bajada areas and 303 in rocky areas (Table 6.2). 

Analysis

We analyzed all photos and identified the animals 

present. A few species pairs (black-tailed and 

antelope jackrabbits, hooded and striped skunks, 

and kit and gray foxes) are difficult to distinguish 

under poor light conditions or if only part of 

the animal is visible; for these we made the 

best possible attempt to distinguish them, and 

sometimes identified the individual to genus 

only. We entered these and other data (species, 

number of individuals, film number, location, 

date, time if available, bait, etc.) into an Access 

database. We excluded from analysis all nonmammals (birds, reptiles, and blanks) as well as 

unknowns that could not be identified to genus, 

humans, horses with riders, and nocturnal rodents 

(mostly woodrats). For each camera location 

we summarized the number of photographs and 

number of individuals photographed for each 

species. To create species distribution maps, we 

converted UTM coordinates to NAD 83 datum 

and imported them into ArcView (these maps 

are available only at the park and I&M office in 

Tucson).

Comparing species abundance and 

presence among locations using infraredtriggered photography is problematic. As with 

all methods, animals may not be detected because 

they are absent, or because they were present 

and not detected. In addition, rates of detection 

undoubtedly vary greatly among species. 

Determining relative abundance can also be 

difficult. Infrared-triggered camera units often do 

not operate continuously between the time they 

are set and when they are next checked because 

the film may be shot out or because the unit may 

fail due to technical problems or field errors. To 

estimate relative abundance based on effort, we 

used dates on photographs to determine as closely 

as possible how many nights a camera unit was 

operating for each roll of film, then summed the 

number of operational days at each location. 

Where dates were not available for a roll of film, 

Receiver Transmitter

(1) Animal blocks infrared beam 

from getting to receiver 

(2) Receiver

triggers

camera to 

take picture 

Camera Infrared beam

Figure 6.5. Typical configuration for an active infrared-triggered camera system. Image 

based on Swann et al. (2004).
54

we substituted the mean number of days it took 

to fill a roll of film (11.76 days). Because no 

photograph dates were recorded during the 2001 

and 2002 effort, we did not include data from 

this period in the analysis. Relative abundance 

was presented as the number of photographs per 

operational day times 100. 

Results

Species Richness

We confirmed a total of 32 species of mammals 

in Saguaro National Park’s Tucson Mountain 

District (Appendix D). This includes two species 

confirmed through specimens only, 15 species 

confirmed through photographs only, eight 

species confirmed through a combination of both 

specimens and photos, and seven species captured 

for which a voucher specimen or a reliable 

report previously existed. This total includes 

only species for which we have photographs or 

voucher specimens; two additional species (brush 

mouse and coati) may have been observed but 

could not be confirmed during our study.

We confirmed nine species of mammals not 

previously confirmed for TMD, although these 

species were already believed to be present (e.g., 

Doll et al. 1989). We did not observe any species 

Table 6.2. Summary of infrared-triggered camera effort, Saguaro NP, 

Tucson Mountain District, 2002-2005. This table does not include camera 

use during 2001 and 2002 because we could not calculate effort for this 

period (see text); data from 2001 and 2002 are reported separately in the 

Results. Low slope <10o, high slope > 10o.

Type of camera Site characteristics Number of estimated camera-nights

Non-random Bajada 296

Rocky slopes 91

Random Bajada 1154

Rocky slopes 212

Total 1753

Table 6.3. Relative abundance of small mammals trapped at Saguaro NP, Tucson Mountain District, 2001 and 

2002 at random (R) and non-random (NR) trapping grids. Numbers 1 and 2 in table heading indicate visit number. 

See Table 6.1 and Appendix I for details of effort (e.g., trap nights), dates of trapping, and grid configuration information. 

Plot group

212 213 238 239

Kinney 

Road

Sandario 

Road

R NR R NR R R NR NR NR

Species 1 1 1 2 1 1 1 2 1 1 1

Harris’ antelope squirrel 0.9

pocket mouse species 2.6 3.5 0.7 5.3 0.5 1.3 7.5 8.2 1.3 0.6

Arizona pocket mouse 2.3 2.2 3.8 14.2 2.1 0.6

Sonoran Desert pocket mouse 1.3 26.4 18.6

rock pocket mouse 3.3 0.6 2.2 7.6 8.2 1.3 1.7

Bailey’s pocket mouse 0.8 3.5 8.1 5.3 0.5 1.3 1.9 2.1 0.4

Merriam’s kangaroo rat 13.3 7.5 6.2

unknown white-footed mouse 2.6 1.2 1.4

cactus mouse 1.8 0.7

unknown woodrat 0.9

western white-throated woodrat 2.5 3.8 0.9

All species 6.6 5.2 12.9 14.0 10.5 2.3 32.3 60.4 45.4 3.1 2.9

Species richness 3 2 4 4 1 2 6 6 5 2 2

Species richness by plot group 4 4 2 7 2 2
55

listed by the U.S. Fish and Wildlife Service as 

endangered or threatened. We documented two 

non-native animals (feral cat and domestic dog); 

domestic dogs are a potential management issue, 

but we found no evidence that either species has 

established feral populations in the district. 

Based on a review of our inventory and 

other studies in the district, there have been a 

total of 40 species of mammals confirmed or 

reliably documented in the Tucson Mountain 

District of Saguaro National Park since it was 

established in 1961. We could not confirm four 

species that have been previously confirmed for 

TMD and four others that have been reliably 

documented. The previously confirmed species 

include two bats, Townsend’s big-eared bat 

and big brown bat (Sidner and Davis 1994) 

that probably still occur at the district, and two 

rodents, Arizona cotton rat (collected at TMD in 

1993 [SNP specimen records], and deer mouse 

(a single specimen from 1970 near the northern 

TMD boundary). Reliably documented species 

include southern grasshopper mouse, which has 

been trapped by Robert Parmenter (unpublished 

data; SNP files) as well as by Yensen (1973); 

a house mouse recorded by Yensen (1973) for 

which no specimen was collected, and two 

species that appear to be extirpated from TMD: 

bighorn sheep (Coss 1969) and North American 

porcupine (SNP records, 1975). Coatis have 

also been observed at TMD (SNP observation 

database), but we are not certain if these are 

reliable observations. 

Small Mammals

We trapped 254 individual rodents (including 

45 recaptures) and documented eight species 

(Table 6.3) through our trapping effort, including 

one of the three species of diurnal squirrels also 

documented by infrared-triggered photography. 

There were no species found to be new for the 

district; we could not confirm the identity of 

a brush mouse identified as such in the field 

but not brought in for expert identification. As 

noted previously, we did not capture four species 

previously documented for TMD. 

Small mammal species richness was eight 

on random plots and six on non-random plots 

(Table 6.2), though sampling effort was also 

greater on random plots. The single bajada site 

that we trapped, plot 239, had the most species 

captured (7) and the highest relative abundance of 

any site for six of these species. 

Bats

We confirmed only three species of bats during 

2001 and 2002: California leaf-nosed bat, cave 

myotis, and western pipistrelle (Table 6.4). The 

most widespread species was the cave myotis, 

which we found at one mine site (on both visits) 

and at both tanks at which we placed nets. We 

found California leaf-nosed bat at both mine sites 

and it numbered at least 18 individuals at the 

Yuma mine site. In total, we observed greater 

than 25 bats at roost sites and trapped 12 bats at 

water sources (Table 6.4). The percent netting 

success was 57.1% at Dobe Wash and 8.3% at 

Javelina Wash. 

Medium and Large Mammals

2001 and 2002 

We took 181 photographs of 197 individual 

mammals representing 12 species (not including 

nocturnal rodents and people) during the early 

photography effort 2001 and 2002 (Table 6.5). 

The largest number of photographs was of the 

gray fox (127 photos). 

Table 6.4. Results of roost site detections and netting for bats, Saguaro NP, Tucson Mountain 

District, 2001 and 2002. See Appendix J for additional information. 

Type of investigation Study site Species Number observed/captured

Roost Gould Mine California leaf-nosed bat 2

cave myotis 5

Yuma Mine California leaf-nosed bat 18+

Netting Dobe Wash Tank cave myotis 7

western pipistrelle 3

Javelina Wash Tank cave myotis 1

western pipistrelle 1
56

2002-2005 

In 1,753 estimated camera-nights during 2002-

2005, we took 1,525 photographs that captured 

at least one mammal that could be identified to 

genus, and a total of 1,701 individual mammals 

(Table 6.5). We photographed 21 species, 

including one non-native species, the domestic 

dog. The largest number of photographs was of 

the gray fox (455 photos), followed by collared 

peccary (307 photos), coyote (238 photos), 

and desert cottontail (169 photos). Cameras at 

non-random sites captured an average of 0.99 

photographs per camera-night compared with 

0.84 at random sites. Species richness was 

similar at random (18) and non-random sites (17), 

although effort was greater at random sites. 

Relative abundance of a number of species, 

including coyote, mule deer, black-tailed 

jackrabbit, and desert cottontail was higher in 

bajada areas than in rocky areas of higher slope, 

as was overall relative abundance (Table 6.5). 

Species richness was 18 in bajada areas and 14 

in rocky areas, though effort was greater on the 

bajada.

Inventory Completeness

We confirmed a total of 32 species of mammals 

in the district, and failed to confirm eight 

species previously documented for the Tucson 

Mountains. Of these eight, two species (bighorn 

sheep and American porcupine) are certainly 

extirpated from the district. We believe that two 

species of bats and at least one rodent (southern 

grasshopper mouse) documented in the past 

are still present and would be confirmed with 

additional survey effort. Due to lack of habitat 

at the district, three rodents detected in the past 

(deer mouse, house mouse, and Arizona cotton 

rat) are probably rare or transient at TMD, as are 

raccoons and coatis. Based on historic records, 

Table 6.5. Number of photographs of mammal species, from infrared-triggered photography, Saguaro 

NP, Tucson Mountain District, 2001-2005. Relative abundance (RA) is number of photographs of that 

species per estimated number of working camera-nights. Does not include individuals that could be identified 

to genus, but not species (e.g., some photos of deer, skunks, rabbits, and squirrels). 

2001-2002 2002-2005 Bajada 2002-2005 Rocks

Species No. Photos RA No. Photos RA No. Photos RA

ringtail 4 - 4 .3 7 2.3

common raccoon 0 - 1 0.1 0 0

American badger 2 7 0.5 0 0

striped skunk 1 - 1 0.1 1 0.3

hooded skunk 7 - 44 3.0 11 3.6

white-backed hog-nosed skunk 3 - 3 0.2 0 0

western spotted skunk 3 - 0 0 1 0.3

unknown skunk 0 - 0 0 6 2.0

coyote 7 - 225 15.5 13 4.3

domestic dog 0 - 2 0.1 1 0.3

common gray fox 127 - 356 24.6 99 32.7

kit fox 0 2 0.1 0 0

mountain lion 0 - 5 0.3 2 0.7

bobcat 2 - 24 1.7 10 3.3

round-tailed ground squirrel 0 - 2 0.1 0 0

rock squirrel 1 - 23 1.6 6 2.0

Harris’ antelope squirrel 0 - 17 1.2 0 0

antelope jackrabbit 0 - 22 1.5 0 0

black-tailed jackrabbit 4 - 87 6.0 7 2.3

unknown jackrabbit 0 8 0.6 0 0

desert cottontail 0 - 168 11.6 1 0.3

collared peccary 20 - 278 19.2 29 9.6

mule deer 0 - 50 3.5 2 0.7

Totals 181 - 1329 91.7 196 64.7

Species richness 12 21 14
57

if we assume that six species of rodents and 

bats went undetected, our inventory confirmed 

84% of mammals known for the district. The 

species accumulation curve for small mammal 

trapping (Fig. 6.6) suggests that we may have 

trapped additional species with greater effort, 

and we certainly would have detected more bats 

with greater effort. The species accumulation 

curve for infrared-triggered cameras (Fig. 6.7) 

suggests that our inventory for medium and large 

mammals was fairly complete.

The nine “new” species reported during this 

study were probably not previously confirmed 

simply due to lack of previous inventory effort. 

Indeed, some of these species (especially Harris 

antelope squirrel) are quite common at the 

district. However, we were pleased to detect 

American badgers and kit foxes, two species that 

do not appear to be common at TMD and may be 

declining due to habitat loss outside the district. 

We believe that more bats would be 

detected with a more intensive survey effort. 

Sampling period

0 2 4 6 8 10 12 14

Cumulative number of species 4

5

6

7

8

9

Sample period

0 10 20 30 40

Cumulative number of species

6

8

10

12

14

16

18

20

Figure 6.6. Species accumulation curve for small-mammal trapping, Saguaro NP, Tucson Mountain 

District, 2001. Each sampling period represents a random ordering of 10 observations. 

Figure 6.7. Species accumulation curve for infrared-triggered photography, Saguaro NP, Tucson 

Mountain District, 2002-2005. Each sampling period represents a random ordering of 10 observations. 
58

Because bats congregate at water sources, 

detecting bats at TMD is more difficult than in 

many other parks in the region because there are 

no large water sources where mist-netting can be 

conducted, and water in general is scarce. Dr. 

Ronnie Sidner, who collected data for this effort 

and is a regional expert on the distribution and 

ecology of bats (see Sidner and Davis 1994), 

believes that an additional 10 species could be 

found in the district with additional survey effort 

(Table 6.6). We encourage the park to promote 

additional studies of bats at TMD, particularly as 

newer audio technologies develop. 

Additional species of rodents near the edge 

of their geographic range could also be present at 

TMD (Table 6.6), but the lack of grassland and 

riparian habitats make this unlikely for most of 

the species listed. The two species most likely to 

be found in the future are probably Botta’s pocket 

gopher and banner-tailed kangaroo rat. We have 

recently observed burrowing activity that could 

be that of pocket gophers (Don Swann, Erin 

Zylstra, pers. obs.). 

Discussion 

Despite its close proximity to Tucson, the 

Tucson Mountain District has had only a few 

mammal studies. Our study represents the 

first comprehensive inventory of the district 

and the first to quantify relative abundance and 

distribution of species; we intend that it will 

provide a good baseline for evaluating future 

changes in the mammal community at the district, 

and will also lead to additional research on 

mammals of concern. 

Biogeography

As noted in other chapters, the Tucson Mountain 

District stands in unique geographic contrast to 

the Rincon Mountain District (RMD) of the park. 

The Rincon Mountains have great topographical 

diversity, rising from the desert floor to more 

than 8600’ (2621 m) in elevation, and contain 

elements of several major biogeographic 

provinces. By contrast, the Tucson Mountains 

are a desert range, with a peak elevation of 4687’ 

(1429 m). Not surprisingly we confirmed 59 

species of mammals in the RMD, and 32 at TMD. 

However, the Tucson Mountains do contain 

elements of the Lower Colorado subdivision of 

the Sonoran Desert not found at RMD, which 

increases diversity of desert mammals. 

The mammal community of the Tucson 

Mountains is dominated by “classic” desert 

species, including Merriam’s kangaroo rats, 

round-tailed ground squirrels, Sonoran Desert 

Table 6.6. List of possible bat and rodent species for Saguaro NP, Tucson Mountain 

District. Bat list developed by Ronnie Sidner based on her knowledge of the distribution and 

habitat requirements of bats; rodent list from Hoffmeister (1986) based on specimens collected 

within approximately 10 miles of TMD. 

Family Scientific name Common name

Phyllostomidae Choeronycteris mexicana Mexican long-tongued bat

Leptonycteris curasoae yerbabuenae southern long-nosed bat

Vespertilionidae Myotis californicus California myotis

Myotis ciliolabrum western small-footed myotis

Lasiurus xanthinus western yellow bat

Antrozous pallidus pallid bat

Molossidae Tadarida brasiliensis Brazilian free-tailed bat

Nyctinomops femorosaccus pocketed free-tailed bat

Nyctinomops macrotis big free-tailed bat

Eumops perotis californicus western bonneted bat

Heteromyidea Dipodomys spectabilis banner-tailed kangaroo rat

Dipodomys ordii Ord’s kangaroo rat

Perognatus flavus Silky pocket mouse

Muridae Reithrodontomys fulvescens fulvous harvest mouse

Reithrodontomys megalotis western harvest mouse

Peromyscus merriami mesquite mouse

Peromuscus leucopus white-footed mouse

Geomyidae Thomomys bottae Botta’s pocket gopher
59

pocket mice, cave myotis, and mule deer. A 

number of other species, particularly bats and 

grassland rodents, occur nearby, but are just 

beyond the western and southern edges of their 

range. For example, red bats, yellow-nosed 

cotton rats, fulvous harvest mice, and a number 

of other species occur in the Santa Catalina and 

Rincon mountains, but probably not in the Tucson 

Mountains (Hoffmeister 1986). It is possible that 

with more intensive effort these species might 

be found in the Tucson Mountains, but it is more 

probable that they do not occur in the district due 

to the lack of riparian and grassland habitats. 

Habitat Associations

We chose to stratify by habitat type in this 

inventory based on slope rather than elevation, 

because elevation differences are not significant 

at Tucson Mountain District, yet changes in 

substrate characteristics throughout the district 

are striking. Changes in slope from low to 

high correspond with changes in geology. In 

the valley bottoms, soils are loose and fine; at 

the base of the mountains soils are coarse, and 

larger boulders are present; and the mountains 

themselves are extremely rocky. As seen in 

other chapters of this report, the vegetation and 

herpetofauna also vary with changes in slope 

(see also Yang and Lowe 1956). It is noteworthy 

that abundance and diversity of both small and 

large mammals were greater in the bajada than in 

rocky areas. This may correspond with greater 

availability of food, including grass seeds and the 

rodents that eat these seeds. A number of species, 

such as kit fox, badger, Merriam’s kangaroo rats, 

round-tailed ground squirrels, and others, occur 

almost exclusively in areas with friable soil. In 

contrast, ringtails and rock pocket mouse are 

rarely found far from rock outcrops. Unlike 

the Rincon Mountains, TMD has no perennial 

water sources and no mesic riparian vegetation. 

The xeric riparian washes, however, are likely 

corridors and places of increased cover suitable 

for larger mammals. 

Changes in the Mammal Community

In the RMD we found evidence of important 

changes in the mammal community since the 

establishment of the park in 1933 (Swann and 

Powell 2006b). If these patterns are evident in 

the Tucson Mountain District, they do not appear 

to be as pronounced. However, as in the Rincon 

Mountains, lack of historic data preclude a full 

understanding of the situation. Like the Rincon 

Mountains, the Tucson Mountains have lost 

bighorn sheep, which were detected on game 

surveys in the 1930s (Saguaro NP historical 

data). It is not known when this species was 

extirpated from the TMD, but the last recorded 

sighting was in 1957 (Coss 1969). It seems 

possible that other large mammals that have 

disappeared from southern Arizona during the 

past century, including Mexican gray wolves, 

were once present in the Tucson Mountains as 

well, but the habitat for these forest animals was 

limited at best. 

In southern Arizona, North American 

porcupines occupy a variety of habitats, including 

desert and semidesert grassland (Hoffmeister 

1986). Little is known about porcupines at TMD, 

but “several” skeletons of this species were 

observed near the Wasson Peak Trail in 1975 by 

a park ranger (SNP, historical data). Porcupines 

appear to be declining for unknown reasons 

in southern Arizona, possibly due to habitat 

changes, although Harley Shaw (pers. comm.) 

has suggested that it is due to the large increase 

in the population of mountain lions. We found 

no evidence that porcupines occur at TMD and 

consider them extirpated. 

Unlike the Rincon Mountains, gross habitat 

changes at TMD in recent decades do not appear 

to be significant. Grazing in the park, currently 

excluded, was never heavy at TMD and appears 

to have ended in 1934 when the county park 

was established (Borell 1936, Saguaro National 

Park, 1987). The Sonoran Desert typically is 

not fire-adapted so there is little history of fire 

suppression at TMD. There is a long history of 

mining in the district, but few of these mines 

were large. Predator control of coyotes probably 

occurred during the mid 20th century in the 

Tucson Mountains, but we have been unable to 

document this. 

The major current issue at TMD is habitat 

loss outside the boundary of the district, as well 

as urban impacts inside the district associated 

with roads. Species that may be most negatively 
60

affected by habitat changes, and indeed may 

face extirpation from TMD, include American 

badgers, kit foxes, and other low desert species 

for which there is only a limited amount of 

habitat in the district. In addition, it seems that 

mountain lions, which require large amounts of 

land, could be losing their ability to move easily 

in and out of the Tucson Mountains. All three 

of these species appear to be rare at TMD. Kit 

foxes occurred in high and low densities along 

the edges of TMD in the early 1980s (deVos et 

al. 1983) and were captured readily (6 in 167 

trap-nights) for a study just north of TMD (at 

Twin Peaks) in 1988 (Harper and Messing 1987). 

It seems likely that this species is declining as 

habitat outside the district decreases. Mountain 

lions still occur in low numbers at TMD (Hackl 

et al. 2006, Haynes and Swann, in prep.). It is 

unknown if badgers were ever common at TMD, 

but they share similar habitat as kit foxes and are 

probably impacted by loss of this habitat outside 

the district. In contrast, urban development 

probably favors species that adapt well to 

humans, such as coyotes and bobcats. 

Management Implications

Like many natural areas (Newmark 1995, Powell 

et al. 2006a), the Tucson Mountain District of 

Saguaro National Park has seen some loss of 

mammal species since it was established as a 

park (originally, as a county park) in the 1930s. 

Our study indicates that these losses may be 

continuing at the district, with the diminishing 

habitat outside the district being the primary 

concern for medium and large mammals at the 

present time. It seems probable that significant 

management efforts would be needed to prevent 

the future extirpation of species like American 

badger and mountain lion. The major issue for 

TMD, in contrast to RMD, is that the district is 

relatively small and is on the verge of becoming 

completely isolated by barriers to movement by 

mammals. 

While some species have declined or 

disappeared during the park’s history, others 

have increased. The park deserves credit for 

instituting land management practices that have 

improved habitat for many species. NPS policies, 

including cessation of cattle grazing, banning 

of hunting and trapping, elimination of off-road 

vehicles, and restriction of road-building have 

all helped to improve conditions for mammals 

at the district. On the other hand, the lack of 

high-profile encounters between humans and 

mountain lions at the park, so far, have probably 

been at least partly a matter of good luck. Park 

managers are currently working on plans for lion 

management that include responding to humanlion encounters. 

Areas for future research should focus on 

mammals for which little data are available, such 

as kit fox, American badgers, mule deer, and 

bats. Additional inventory work should focus on 

bats and rodents, and an effort should be made 

to determine the status of pocket gophers on the 

district. 

The major ecological changes that are 

occurring throughout the west are certainly 

impacting mammal populations at Saguaro 

National Park. In the future, habitat loss outside 

of district boundaries will probably continue 

to reduce the great mammal diversity that 

Saguaro National Park has but, at the same time, 

knowledge of this loss should only make the 

preservation of parklands more critical in the 

years to come. 
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67

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Acanthaceae Anisacanthus thurberi (Torr.) Gray Thurber’s desert honeysuckle X X

Carlowrightia arizonica Gray Arizona wrightwort X O X O

Justicia californica (Benth.) D. Gibson beloperone X X

Justicia candicans (Nees) L. Benson Arizona water-willow O

Ruellia nudiflora (Engelm. & Gray) Urban violet wild petunia X X

Siphonoglossa longiflora (Torr.) Gray longflower tubetongue X X X

Agavaceae Agave schottii Engelm. Schott’s century plant X X O

Yucca baccata Torr. banana yucca X

Yucca baccata var. brevifolia (Schott ex Torr.) L. 

Benson & Darrow Spanish dagger X X

Yucca elata (Engelm.) Engelm. soaptree yucca X

Amaranthaceae Amaranthus fimbriatus (Torr.) Benth. ex S. Wats. fringed amaranth X O O

Amaranthus fimbriatus var. denticulatus (Torr.) 

Uline & Bray fringed amaranth X

Amaranthus fimbriatus (Torr.) Benth. ex S. Wats. 

var. fimbriatus fringed amaranth X

Amaranthus palmeri S. Wats. carelessweed X O X

Tidestromia lanuginosa (Nutt.) Standl. woolly tidestromia X O X X

Anacardiaceae Rhus aromatica Ait. fragrant sumac X

Rhus trilobata var. pilosissima Engelm. pubescent squawbush O X

Apiaceae Bowlesia incana Ruiz & Pavón hoary bowlesia O X O X O

Daucus pusillus Michx. American wild carrot X X O X X

Lomatium nevadense (S. Wats.) Coult. & Rose Nevada biscuitroot X

Lomatium nevadense (S. Wats.) Coult. & var. 

nevadense Nevada biscuitroot X

Spermolepis echinata (Nutt. ex DC.) Heller bristly scaleseed X X O X X

Yabea microcarpa (Hook. & Arn.) K.-Pol. false carrot X X

Apocynaceae Haplophyton crooksii (L. Benson) L. Benson cockroachplant X X X

Aristolochiaceae Aristolochia watsonii Woot. & Standl. Watson’s dutchman’s pipe X O X

Asclepiadaceae Asclepias lemmonii Gray Lemmon’s milkweed O

Asclepias nyctaginifolia Gray Mojave milkweed X X

Cynanchum arizonicum (Gray) Shinners Arizona swallow-wort X O

Funastrum cynanchoides ssp. cynanchoides

(Dcne.) Schlechter fringed twinevine X

Funastrum cynanchoides ssp. heterophyllum

(Vail) Kartesz, comb. nov. ined. Hartweg’s twinevine X O X

Matelea parvifolia (Torr.) Woods. spearleaf X X X

Matelea producta (Torr.) Woods. Texas milkvine X

Asteraceae Acourtia nana (Gray) Reveal & King dwarf desertpeony O X

Acourtia wrightii (Gray) Reveal & King brownfoot X X O X

Adenophyllum porophylloides (Gray) Strother San Felipe dogweed X X O X O

Ambrosia ambrosioides (Cav.) Payne ambrosia leaf burr ragweed O X O X O

Ambrosia confertiflora DC. weakleaf burr ragweed X O X O

Ambrosia cordifolia (Gray) Payne Tucson burr ragweed X

Ambrosia deltoidea (Torr.) Payne triangle burr ragweed O O X O

Ambrosia dumosa (Gray) Payne burrobush O X O

Ambrosia psilostachya DC. Cuman ragweed O

Antheropeas lanosum (Gray) Rydb. white easterbonnets X X O X O

Artemisia ludoviciana Nutt. white sagebrush X

Artemisia ludoviciana ssp. albula (Woot.) Keck white sagebrush X

Artemisia ludoviciana ssp. sulcata (Rydb.) Keck white sagebrush X

Appendix A. List of plant species that were observed (O) or collected (X) at Saguaro NP, Tucson Mountain District. 

Species list derives from: species seen or collected by UA Inventory effort (UA), specimens from 1909–1994 located in the 

University of Arizona Herbarium (UAH), Van Devender (VnD; 1992), Rondeau et al. (Rea; 1996), Halvorson and Guertin (H&G; 

2003), Saguaro National Park long-term monitoring plots 1998–2004 (SNP; In prep). Species in bold-faced type are non-native 

according to USDA (2004).
68

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Asteraceae Baccharis brachyphylla Gray shortleaf baccharis

XX

Baccharis salicifolia (Ruiz & Pavón) Pers. mule’s fat

XX

Baccharis sarothroides Gray desertbroom

OX

Bahia absinthifolia Benth. hairyseed bahia

XO

Baileya multiradiata Harvey & Gray ex Gray desert marigold

OOX

Baileya pleniradiata Harvey & Gray ex Gray woolly desert marigold

X

Bebbia juncea (Benth.) Greene sweetbush

OXO

Bebbia juncea var. aspera Greene sweetbush

X

Brickellia baccharidea Gray resinleaf brickellbush

X

Brickellia californica (Torr. & Gray) Gray California brickellbush

XX

Brickellia coulteri Gray Coulter’s brickellbush

XOXO

Brickellia simplex Gray Sonoran brickellbush

O

Calycoseris parryi Gray yellow tackstem

XX

Calycoseris wrightii Gray white tackstem

OXOX

Chaenactis carphoclinia Gray pebble pincushion

XX

Chaenactis stevioides Hook. & Arn. Steve’s dustymaiden

XOXX

Chaetopappa ericoides (Torr.) Nesom rose heath

O

Cirsium neomexicanum Gray New Mexico thistle

X

Conyza canadensis (L.) Cronq. Canadian horseweed

X

Dimorphotheca sinuata DC. glandular cape marigold

XX

Encelia farinosa Gray ex Torr. goldenhills

OXOO

Encelia farinosa Gray ex Torr. var. farinosa goldenhills

X

Encelia frutescens (Gray) Gray button brittlebush

XX

Ericameria cuneata (Gray) McClatchie cliff goldenbush

XX

Ericameria laricifolia (Gray) Shinners turpentine bush

XX

Erigeron colomexicanus A. Nels. running fleabane

XX

Erigeron divergens Torr. & Gray spreading fleabane

XOX

Erigeron lobatus A. Nels. lobed fleabane

XX

Filago arizonica Gray Arizona cottonrose

XOXO

Filago californica Nutt. California cottonrose

XXOXO

Filago depressa Gray dwarf cottonrose

XXOXO

Gnaphalium palustre Nutt. western marsh cudweed

O

Guardiola platyphylla Gray Apache plant

X

Gymnosperma glutinosum (Spreng.) Less. gumhead

XX

Heliomeris longifolia var. annua (M.E. Jones) 

Yates longleaf false goldeneyeXX

Heterotheca subaxillaris (Lam.) Britt. & Rusby camphorweed

OX

Hymenoclea salsola Torr. & Gray ex Gray burrobrush

OXO

Hymenoclea salsola var. pentalepis (Rydb.) 

L. Benson burrobrushOX

Hymenothrix wislizeni Gray TransPecos thimblehead

XOX

Isocoma tenuisecta Greene burroweed

X

Iva ambrosiifolia (Gray) Gray ragged marshelder

X

Koanophyllon solidaginifolium (Gray) King & 

H.E. Robins. shrubby thoroughwortXX

Laennecia coulteri (Gray) Nesom conyza

X

Lasthenia californica DC. ex Lindl. California goldfields

XX

Machaeranthera gracilis (Nutt.) Shinners slender goldenweed

XX

Machaeranthera parviflora Gray smallflower tansyaster

O

Machaeranthera pinnatifida (Hook.) Shinners lacy tansyaster

XO

Machaeranthera pinnatifida var. pinnatifida

(Hook.) Shinners lacy tansyasterOX

Machaeranthera tagetina Greene mesa tansyaster

XX

Malacothrix californica DC. California desertdandelion

X

Malacothrix clevelandii Gray Cleveland’s desertdandelion

XXX

Malacothrix fendleri Gray Fendler’s desertdandelion

OX

Malacothrix glabrata (Gray ex D.C. Eat.) Gray smooth desertdandelion

X

Monoptilon bellioides (Gray) Hall Mojave desertstar

XOX
69

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Asteraceae Parthenium incanum Kunth mariola

OXOXO

Pectis filipes Harvey & Gray fivebract cinchweed

XX

Pectis linifolia L. romero macho

X

Pectis papposa Harvey & Gray manybristle cinchweed

XOXX

Perityle emoryi Torr. Emory’s rockdaisy

XX

Perityle lemmonii (Gray) J.F. Macbr. Lemmon’s rockdaisy

XX

Porophyllum gracile Benth. slender poreleaf

OXOXO

Porophyllum ruderale (Jacq.) Cass. yerba porosa

O

Pseudognaphalium canescens ssp. canescens

(DC.) W.A. Weber Wright’s cudweedXX

Psilostrophe cooperi (Gray) Greene whitestem paperflower

OOXO

Rafinesquia californica Nutt. California plumseed

OXX

Rafinesquia neomexicana Gray New Mexico plumseed

XXOXX

Senecio flaccidus var. monoensis (Greene) B.L. 

Turner & T.M. Barkl. Mono ragwortXOXO

Senecio lemmonii Gray Lemmon’s ragwort

XX

Sonchus asper (L.) Hill spiny sowthistle

X

Sonchus oleraceus L. common sowthistle

XOX

Stephanomeria pauciflora (Torr.) A. Nels. brownplume wirelettuce

OXO

Stylocline micropoides Gray woollyhead neststraw

XOX

Thymophylla pentachaeta var. pentachaeta (DC.) 

Small fiveneedle pricklyleafX

Trixis californica Kellogg American threefold

XXOXO

Uropappus lindleyi (DC.) Nutt. Lindley’s silverpuffs

XOXO

Zinnia acerosa (DC.) Gray desert zinnia

XXOXO

Bignoniaceae Tecoma stans (L.) Juss. ex Kunth yellow trumpetbush

XXO

Boraginaceae Amsinckia menziesii var. intermedia (Fisch & C.A. 

Mey.) Ganders common fiddleneckOXOXX

Amsinckia tessellata Gray bristly fiddleneck

XOX

Cryptantha angustifolia (Torr.) Greene Panamint cryptantha

XXOX

Cryptantha barbigera (Gray) Greene bearded cryptantha

XXOX

Cryptantha decipiens (M.E. Jones) Heller gravelbar cryptantha

XXOX

Cryptantha fendleri (Gray) Greene sanddune cryptantha

O

Cryptantha maritima (Greene) Greene Guadalupe cryptantha

XXX

Cryptantha micrantha (Torr.) I.M. Johnston redroot cryptantha

XOX

Cryptantha nevadensis A. Nels. & Kennedy Nevada cryptantha

XX

Cryptantha pterocarya (Torr.) Greene wingnut cryptantha

XXOX

Harpagonella palmeri Gray Palmer’s grapplinghook

XXX

Lappula occidentalis var. occidentalis (S. Wats.) 

Greene flatspine stickseedXXO

Pectocarya heterocarpa (I.M. Johnston) I.M. 

Johnston chuckwalla combseedXOX

Pectocarya platycarpa (Munz & Johnston) Munz & 

Johnston broadfruit combseedOXOX

Pectocarya recurvata I.M. Johnston curvenut combseed

XXOX

Plagiobothrys arizonicus (Gray) Greene ex Gray Arizona popcornflower

XXO

Tiquilia canescens (DC.) A. Richards. woody crinklemat

X

Arabis perennans S. Wats. perennial rockcress

OX

XO

Brassicaceae Brassica tournefortii Gouan Sahara mustard

XOXX

Capsella bursa-pastoris (L.) Medik. shepherd’s purse

XX

Descurainia pinnata (Walt.) Britt. western tansymustard

XOXX

Descurainia sophia (L.) Webb ex Prantl herb sophia

XX

Draba cuneifolia Nutt. ex Torr. & Gray wedgeleaf draba

XXOXX

Dryopetalon runcinatum Gray rockmustard

XX

Guillenia lasiophylla (Hook. & Arn.) Greene California mustard

XXOXX

Lepidium lasiocarpum Nutt. shaggyfruit pepperweed

XXOXX

Lepidium virginicum L. Virginia pepperweed

X
70

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Brassicaceae Lepidium virginicum var. medium (Greene) C.L. 

Hitchc. medium pepperweed X O X

Lesquerella gordonii (Gray) S. Wats. Gordon’s bladderpod X O X O

Lesquerella purpurea (Gray) S. Wats. rose bladderpod X X

Pennellia micrantha (Gray) Nieuwl. mountain mock thelypody O

Sisymbrium altissimum L. tall tumblemustard O

Sisymbrium irio L. London rocket O O X O

Sisymbrium orientale L. Indian hedgemustard X O X

Streptanthus carinatus C. Wright ex Gray lyreleaf jewelflower X O X O

Streptanthus carinatus ssp. arizonicus (S. Wats.) 

Kruckeberg, Rodman & Worthington lyreleaf jewelflower X

Thysanocarpus curvipes Hook. sand fringepod O X O X O

Cactaceae Carnegia gigantea (Engelm.) Britt. & Rose saguaro O O X O

Echinocereus fendleri var. fasciculatus (Engelm.

ex B.D. Jackson) N.P. Taylor pinkflower hedgehog cactus O O X O

Echinocereus triglochidiatus Engelm. kingcup cactus X X

Ferocactus cylindraceus (Engelm.) Orcutt California barrel cactus X X X

Ferocactus wislizeni (Engelm.) Britt. & Rose candy barrelcactus O O X O

Mammillaria grahamii Engelm. Graham’s nipple cactus O X O

Mammillaria grahamii var. grahamii Engelm. Graham’s nipple cactus O O

Mammillaria thornberi Orcutt Thornber’s nipple cactus O X O X

Mammillaria viridiflora (Britt. & Rose) Bödecker greenflower nipple cactus X X

Opuntia acanthocarpa Engelm. & Bigelow buckhorn cholla O X O

Opuntia acanthocarpa var. major (Engelm. & 

Bigelow) L. Benson buckhorn cholla O X

Opuntia arbuscula Engelm. Arizona pencil cholla O X O X O

Opuntia bigelovii Engelm. teddybear cholla X

Opuntia chlorotica Engelm. & Bigelow dollarjoint pricklypear X

Opuntia engelmannii Salm-Dyck cactus apple O O

Opuntia engelmannii Salm-Dyck var. engelmannii cactus apple X

Opuntia engelmannii var. linguiformis (Griffiths) 

Parfitt & Pinkava cactus apple X

Opuntia fulgida Engelm. jumping cholla O O

Opuntia fulgida Engelm. var. fulgida jumping cholla O X

Opuntia fulgida var. mamillata (Schott ex Engelm.) 

Coult. jumping cholla O

Opuntia leptocaulis DC. Christmas cactus O O X O

Opuntia phaeacantha Engelm. tulip pricklypear O O O

Opuntia phaeacantha var. major Engelm. Mojave pricklypear X

Opuntia spinosior (Engelm.) Toumey walkingstick cactus X O X

Opuntia versicolor Engelm. ex Coult. staghorn cholla O X O

Opuntia ×kelvinensis V.& K. Grant X O X

Campanulaceae Nemacladus glanduliferus Jepson glandular threadplant X X O X

Triodanis perfoliata var. biflora (Ruiz & Pavón) 

Bradley clasping Venus’ looking-glass X X

Caryophyllaceae Herniaria hirsuta ssp. cinerea (DC.) Coutinho hairy rupturewort O

Loeflingia squarrosa Nutt. spreading pygmyleaf X O X X

Silene antirrhina L. sleepy silene O X O X O

Celastraceae Canotia holacantha Torr. crucifixion thorn O

Chenopodiaceae Atriplex canescens (Pursh) Nutt. fourwing saltbush O X X

Atriplex canescens var. linearis (S. Wats.) Munz thinleaf fourwing saltbush X X

Atriplex elegans (Moq.) D. Dietr. wheelscale saltbush X

Atriplex elegans (Moq.) D. Dietr. var. elegans wheelscale saltbush X

Chenopodium berlandieri Moq. pitseed goosefoot O

Chenopodium incanum (S. Wats.) Heller mealy goosefoot X X

Chenopodium neomexicanum Standl. New Mexico goosefoot X O X X

Monolepis nuttalliana (J.A. Schultes) Greene Nuttall’s povertyweed X O
71

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Chenopodiaceae Salsola kali L. Russian thistle X

Salsola tragus L. prickly Russian thistle X

Convolvulaceae Evolvulus alsinoides (L.) L. slender dwarf morning-glory X O X X

Evolvulus arizonicus Gray wild dwarf morning-glory O

Evolvulus nuttallianus J.A. Schultes shaggy dwarf morning-glory X X

Ipomoea barbatisepala Gray canyon morning-glory X X

Ipomoea coccinea L. redstar X

Ipomoea costellata Torr. crestrib morning-glory X X

Ipomoea cristulata Hallier f. Transpecos morning-glory X X

Crassulaceae Crassula connata (Ruiz & Pavón) Berger sand pygmyweed O X

Crassula connata var. connata (Ruiz & Pavón) 

Berger sand pygmyweed X O X X

Crossosomataceae Crossosoma bigelovii S. Wats. ragged rockflower X X

Cucurbitaceae Apodanthera undulata Gray melon loco X X

Citrullus lanatus (Thunb.) Matsumura & Nakai 

var. lanatus watermelon X

Cucurbita digitata Gray fingerleaf gourd X O X

Echinopepon wrightii (Gray) S. Wats. wild balsam apple X X

Tumamoca macdougalii Rose Tumamoc globeberry X

Cyperaceae Cyperus esculentus L. chufa flatsedge X X

Ephedraceae Ephedra aspera Engelm. ex S. Wats. rough jointfir X

Ephedra nevadensis S. Wats. Nevada jointfir X O

Ephedra trifurca Torr. ex S. Wats. longleaf jointfir O X X

Ephedra viridis Coville Mormon tea O

Euphorbiaceae Acalypha neomexicana Muell.-Arg. New Mexico copperleaf X X

Argythamnia lanceolata (Benth.) Muell.-Arg. narrowleaf silverbush X X X O

Argythamnia neomexicana Muell.-Arg. New Mexico silverbush X X X X

Bernardia incana Morton hoary myrtlecroton X X

Chamaesyce abramsiana (L.C. Wheeler) Koutnik Abrams’ sandmat X O X

Chamaesyce arizonica (Engelm.) Arthur Arizona sandmat X X

Chamaesyce capitellata (Engelm.) Millsp. head sandmat O X X X

Chamaesyce florida (Engelm.) Millsp. Chiricahua Mountain sandmat X O X O

Chamaesyce gracillima (S. Wats.) Millsp. Mexican sandmat X O X X

Chamaesyce hyssopifolia (L.) Small hyssopleaf sandmat X O X O

Chamaesyce melanadenia (Torr.) Millsp. squaw sandmat X X

Chamaesyce micromera (Boiss. ex Engelm.) 

Woot. & Standl. Sonoran sandmat X O X

Chamaesyce pediculifera (Engelm.) Rose & Standl. Carrizo Mountain sandmat X

Chamaesyce polycarpa (Benth.) Millsp. ex Parish smallseed sandmat X X O X O

Chamaesyce setiloba (Engelm. ex Torr.) Millsp. ex 

Parish Yuma sandmat X O X X

Euphorbia eriantha Benth. beetle spurge X X

Euphorbia heterophylla L. Mexican fireplant X X

Jatropha cardiophylla (Torr.) Muell.-Arg. sangre de cristo O O X O

Tragia nepetifolia Cav. catnip noseburn X X

Tragia ramosa Torr. branched noseburn X

Fabaceae Acacia constricta Benth. whitethorn acacia O O X O

Acacia greggii Gray catclaw acacia O O X O

Astragalus arizonicus Gray Arizona milkvetch X X

Astragalus didymocarpus Hook. & Arn. dwarf white milkvetch O X O

Astragalus didymocarpus var. dispermus (Gray) 

Jepson dwarf white milkvetch X

Astragalus lentiginosus Dougl. ex Hook. freckled milkvetch X X

Astragalus lentiginosus var. australis Barneby freckled milkvetch O X

Astragalus nothoxys Gray sheep milkvetch O

Astragalus nuttallianus DC. smallflowered milkvetch O X O
72

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Fabaceae Astragalus nuttallianus var. austrinus (Small) 

Barneby smallflowered milkvetch X

Caesalpinia gilliesii (Hook.) Wallich ex 

D. Dietr. bird-of-paradise shrub O

Calliandra eriophylla Benth. fairyduster O X O X O

Coursetia glandulosa Gray rosary babybonnets O X X

Dalea pogonathera Gray bearded prairie clover X X

Dalea wrightii Gray Wright’s prairie clover X X

Desmodium procumbens (P. Mill.) A.S. Hitchc. western trailing ticktrefoil X

Desmodium procumbens var. exiguum (Gray)

Schub. western trailing ticktrefoil X

Galactia wrightii Gray Wright’s milkpea X X

Hoffmannseggia glauca (Ortega) Eifert Indian rushpea X X

Lotus humistratus Greene foothill deervetch O X O X X

Lotus rigidus (Benth.) Greene shrubby deervetch X X

Lotus salsuginosus Greene coastal bird’s-foot trefoil X

Lotus strigosus (Nutt.) Greene strigose bird’s-foot trefoil X

Lotus strigosus var. tomentellus (Greene) Isely strigose bird’s-foot trefoil X O X

Lupinus concinnus J.G. Agardh scarlet lupine O X O X X

Lupinus sparsiflorus Benth. Mojave lupine O X O X O

Marina calycosa (Gray) Barneby San Pedro false prairie-clover X

Marina parryi (Torr. & Gray) Barneby Parry’s false prairie-clover O X O X X

Medicago sativa L. alfalfa X X

Melilotus indicus (L.) All. annual yellow sweetclover X

Mimosa aculeaticarpa var. biuncifera (Benth.) 

Barneby catclaw mimosa X X

Nissolia schottii (Torr.) Gray Schott’s yellowhood O X

Olneya tesota Gray desert ironwood O O X O

Parkinsonia florida (Benth. ex Gray) S. Wats. blue paloverde X

Parkinsonia microphylla Torr. yellow paloverde O O X O

Phaseolus acutifolius Gray tepary bean X

Phaseolus acutifolius var. latifolius Freeman tepary bean X

Phaseolus acutifolius var. tenuifolius Gray tepary bean X

Phaseolus filiformis Benth. slimjim bean X X

Prosopis velutina Woot. velvet mesquite O O X O

Rhynchosia senna Gillies ex Hook. Texas snoutbean X X

Senna bauhinioides (Gray) Irwin & Barneby twinleaf senna X

Senna covesii (Gray) Irwin & Barneby Coves’ cassia O X O

Vicia ludoviciana Nutt. Louisiana vetch X X O

Vicia ludoviciana ssp. ludoviciana Nutt. Louisiana vetch X

Fagaceae Quercus turbinella Greene Sonoran scrub oak X X

Fouquieriaceae Fouquieria splendens Engelm. ocotillo O X O X O

Gentianaceae Centaurium calycosum (Buckl.) Fern. Arizona centaury X X

Geraniaceae Erodium cicutarium (L.) L’Hér. ex Ait. redstem fillare X O X O

Erodium texanum Gray Texas stork’s bill O O X X

Hydrophyllaceae Eucrypta chrysanthemifolia (Benth.) Greene spotted hideseed X X X

Eucrypta micrantha (Torr.) Heller dainty desert hideseed X O X X

Nama demissum Gray purplemat X X

Nama hispidum Gray bristly nama X O X

Phacelia bombycina Woot. & Standl. Mangas Spring phacelia X

Phacelia caerulea Greene skyblue phacelia X X

Phacelia crenulata Torr. ex S. Wats. cleftleaf wildheliotrope X X

Phacelia crenulata var. ambigua (M.E. Jones)

J.F. Macbr. purplestem phacelia X

Phacelia distans Benth. distant phacelia X X O X

Pholistoma auritum (Lindl.) Lilja blue fiestaflower O X X

Pholistoma auritum var. arizonicum (M.E. Jones) 

Constance Arizona fiestaflower X
73

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Krameriaceae Krameria erecta Willd. ex J.A. Schultes littleleaf ratany X X X

Krameria grayi Rose & Painter white ratany O X O X X

Lamiaceae Hedeoma nanum (Torrey) Briq. X

Hyptis emoryi Torr. desert lavender X X O X

Salvia columbariae Benth. chia O X O X X

Salvia pinguifolia (Fern.) Woot. & Standl. rock sage X

Liliaceae Allium macropetalum Rydb. largeflower onion X X

Calochortus ambiguus (M.E. Jones) Ownbey doubting mariposa lily O

Calochortus kennedyi Porter desert mariposa lily O X X

Dichelostemma capitatum (Benth.) Wood ssp. 

capitatum bluedicks O X X X

Zephyranthes longifolia Hemsl. copper zephyrlily X X

Linaceae Linum grandiflorum Desf. flowering flax X

Linum lewisii Pursh prairie flax X X

Loasaceae Mentzelia affinis Greene yellowcomet X O X

Mentzelia albicaulis (Dougl. ex Hook.) Dougl. 

ex Torr. & Gray whitestem blazingstar X X X

Mentzelia asperula Woot. & Standl. Organ Mountain blazingstar X

Mentzelia jonesii (Urban & Gilg) H.J. Thompson & 

Roberts Jones’ blazingstar X X

Mentzelia texana Urban & Gilg Texas blazingstar X

Malpighiaceae Janusia gracilis Gray slender janusia O X O X O

Malvaceae Abutilon abutiloides (Jacq.) Garcke ex Britt. & 

Wilson shrubby indian mallow X X O

Abutilon incanum (Link) Sweet pelotazo X O O

Abutilon incanum ssp. pringlei (Hochr.) Felger & 

Lowe Pringle’s abutilon X

Abutilon malacum S. Wats. yellow Indian mallow X O X

Abutilon parishii S. Wats. Parish’s Indian mallow X X

Abutilon parvulum Gray dwarf Indian mallow X

Herissantia crispa (L.) Briz. bladdermallow O X O X O

Hibiscus biseptus S. Wats. Arizona rosemallow X X

Hibiscus coulteri Harvey ex Gray desert rosemallow O X X O

Hibiscus denudatus Benth. paleface O X O

Horsfordia newberryi (S. Wats.) Gray Newberry’s velvetmallow X X

Malva parviflora L. cheeseweed mallow O

Sida abutifolia P. Mill. spreading fanpetals X O X O

Sphaeralcea ambigua Gray desert globemallow X X O

Sphaeralcea ambigua ssp. rosacea (Munz & 

Johnston) Kearney rose globemallow X X

Sphaeralcea coulteri (S. Wats.) Gray Coulter’s globemallow X O X

Sphaeralcea emoryi Torr. ex Gray Emory’s globemallow X X

Sphaeralcea laxa Woot. & Standl. caliche globemallow X X O X X

Molluginaceae Mollugo cerviana (L.) Ser. threadstem carpetweed X O X O

Moraceae Morus microphylla Buckl. Texas mulberry X X

Nyctaginaceae Allionia incarnata L. trailing windmills O O X X

Boerhavia coccinea P. Mill. scarlet spiderling O O X O

Boerhavia coulteri (Hook. f.) S. Wats. Coulter’s spiderling O

Boerhavia gracillima Heimerl slimstalk spiderling X

Boerhavia intermedia M.E. Jones fivewing spiderling X O X O

Boerhavia megaptera Standl. Tucson Mountain spiderling X X

Boerhavia scandens L. climbing wartclub O X O X X

Boerhavia spicata Choisy creeping spiderling X X O

Boerhavia wrightii Gray largebract spiderling X X

Mirabilis bigelovii Gray wishbone-bush X X O X O

Mirabilis coccinea (Torr.) Benth. & Hook. f. scarlet four o’clock X X

Mirabilis multiflora (Torr.) Gray Colorado four o’clock X X
74

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Oleaceae Forestiera shrevei Standl. desert olive O X X

Menodora scabra Gray rough menodora O O X O

Onagraceae Camissonia californica (Nutt. ex Torr. & Gray) Raven California suncup X X O

Camissonia chamaenerioides (Gray) Raven longcapsule suncup X X O X X

Camissonia claviformis (Torr. & Frém.) Raven browneyes X

Gaura mollis James velvetweed X X

Oenothera primiveris Gray desert evening-primrose O X X

Orobanchaceae Orobanche cooperi (Gray) Heller desert broomrape X

Orobanche cooperi (Gray) Heller ssp. cooperi desert broomrape X

Oxalidaceae Oxalis albicans ssp. pilosa (Nutt.) Eiten radishroot woodsorrel O

Oxalis alpina (Rose) Rose ex R. Knuth alpine woodsorrel O

Papaveraceae Eschscholzia californica ssp. mexicana (Greene) 

C. Clark California poppy O X O X O

Passifloraceae Passiflora mexicana Juss. Mexican passionflower O

Pedaliaceae Proboscidea althaeifolia (Benth.) Dcne. desert unicorn-plant X O X

Proboscidea parviflora (Woot.) Woot. & Standl. doubleclaw O X

Plantaginaceae Plantago ovata Forsk. desert Indianwheat X O X X

Plantago patagonica Jacq. woolly plantain X X O X X

Plumbaginaceae Plumbago scandens L. doctorbush X X

Poaceae Achnatherum speciosum (Trin. & Rupr.) Barkworth desert needlegrass X X

Alopecurus carolinianus Walt. Carolina foxtail O

Aristida adscensionis L. sixweeks threeawn X X O X O

Aristida californica var. glabrata Vasey Santa Rita threeawn X

Aristida purpurea Nutt. purple threeawn X O O

Aristida purpurea var. nealleyi (Vasey) Allred blue threeawn X X X

Aristida purpurea var. parishii (A.S. Hitchc.) Allred Parish’s threeawn X X

Aristida purpurea var. purpurea Nutt. purple threeawn X X

Aristida ternipes Cav. spidergrass O X O X O

Aristida ternipes var. gentilis (Henr.) Allred spidergrass X X

Arundo donax L. giant reed X

Avena fatua L. wild oat X O X

Bothriochloa barbinodis (Lag.) Herter cane bluestem X X O

Bouteloua aristidoides (Kunth) Griseb. needle grama X X O X O

Bouteloua barbata Lag. sixweeks grama X O X O

Bouteloua chondrosioides (Kunth) Benth. ex 

S. Wats. sprucetop grama O X

Bouteloua curtipendula (Michx.) Torr. sideoats grama O X O X O

Bouteloua eriopoda (Torr.) Torr. black grama X X O

Bouteloua hirsuta Lag. hairy grama X X

Bouteloua repens (Kunth) Scribn. & Merr. slender grama X O X O

Bouteloua rothrockii Vasey Rothrock’s grama O X O

Bouteloua trifida Thurb. red grama X X

Bromus arizonicus (Shear) Stebbins Arizona brome X

Bromus carinatus Hook. & Arn. California brome O X O X

Bromus catharticus Vahl rescuegrass O

Bromus madritensis L. compact brome O

Bromus rubens L. red brome O X X O

Chloris virgata Sw. feather fingergrass X X

Cortaderia selloana (J.A. & J.H. Schultes) 

Aschers. & Graebn. Uruguayan pampas grass O

Cottea pappophoroides Kunth cotta grass X X

Cynodon dactylon (L.) Pers. Bermudagrass X O X X

Dasyochloa pulchella (Kunth) Willd. ex Rydb. low woollygrass X O X X

Digitaria californica (Benth.) Henr. Arizona cottontop O X O X O

Digitaria insularis (L.) Mez ex Ekman sourgrass X

Echinochloa colona (L.) Link jungle rice X X

Elymus elymoides (Raf.) Swezey squirreltail X

Enneapogon desvauxii Desv. ex Beauv. nineawn pappusgrass X X O
75

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Poaceae Eragrostis cilianensis (All.) Vign. ex Janchen stinkgrass X O X

Eragrostis echinochloidea Stapf African lovegrass X X

Eragrostis intermedia A.S. Hitchc. plains lovegrass X

Eragrostis lehmanniana Nees Lehmann lovegrass X X X

Heteropogon contortus (L.) Beauv. ex Roemer & 

J.A. Schultes tanglehead O X O X O

Hilaria belangeri (Steud.) Nash curly-mesquite X X O

Hordeum murinum ssp. glaucum (Steud.) 

Tzvelev smooth barley X O

Hordeum murinum ssp. leporinum (Link) 

Arcang. leporinum barley X

Hordeum pusillum Nutt. little barley X X

Leptochloa dubia (Kunth) Nees green sprangletop X

Leptochloa fusca ssp. uninervia (J. Presl) 

N. Snow Mexican sprangletop X X

Leptochloa panicea ssp. brachiata (Steudl.) 

N. Snow mucronate sprangeltop X

Leptochloa panicea ssp. mucronata (Michx.) 

Nowack mucronate sprangeltop O

Melinis repens (Willd.) Zizka rose Natal grass X X

Muhlenbergia emersleyi Vasey bullgrass X X

Muhlenbergia microsperma (DC.) Trin. littleseed muhly X O X

Muhlenbergia polycaulis Scribn. cliff muhly O

Muhlenbergia porteri Scribn. ex Beal bush muhly X O X O

Muhlenbergia rigens (Benth.) A.S. Hitchc. deergrass X O X

Muhlenbergia tenuifolia (Kunth) Trin. slimflower muhly X X

Panicum hirticaule J. Presl Mexican panicgrass O O

Pappophorum vaginatum Buckl. whiplash pappusgrass X X X

Pennisetum ciliare (L.) Link buffelgrass O X X

Pennisetum setaceum (Forsk.) Chiov. crimson fountaingrass X X X

Phalaris canariensis L. annual canarygrass O

Phalaris minor Retz. littleseed canarygrass O X

Poa bigelovii Vasey & Scribn. Bigelow’s bluegrass X X O X X

Polypogon monspeliensis (L.) Desf. annual rabbitsfoot grass X

Schismus barbatus (Loefl. ex L.) Thellung common Mediterranean grass X X O X X

Setaria grisebachii Fourn. Grisebach’s bristlegrass X X

Setaria leucopila (Scribn. & Merr.) K. Schum. streambed bristlegrass X O X

Setaria vulpiseta (Lam.) Roemer & J.A. Schultes plains bristlegrass X

Sporobolus airoides (Torr.) Torr. alkali sacaton X

Sporobolus contractus A.S. Hitchc. spike dropseed X X

Sporobolus cryptandrus (Torr.) Gray sand dropseed O X

Sporobolus wrightii Munro ex Scribn. big sacaton X X

Tridens muticus (Torr.) Nash slim tridens X X X X

Trisetum interruptum Buckl. prairie false oat O X

Triticum aestivum L. common wheat X X

Urochloa arizonica (Scribn. & Merr.) O. Morrone & 

F. Zuloaga Arizona signalgrass X O X O

Vulpia microstachys (Nutt.) Munro small fescue X

Vulpia microstachys var. ciliata (Beal) Lonard & 

Gould Eastwood fescue X X

Vulpia microstachys var. pauciflora (Scribn. ex

Beal) Lonard & Gould Pacific fescue X

Vulpia octoflora (Walt.) Rydb. sixweeks fescue O X O

Vulpia octoflora var. hirtella (Piper) Henr. sixweeks fescue X X

Vulpia octoflora var. octoflora (Walt.) Rydb. sixweeks fescue X

Polemoniaceae Eriastrum diffusum (Gray) Mason miniature woollystar X X O

Gilia flavocincta A. Nels. lesser yellowthroat gilia X
76

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Polemoniaceae Gilia flavocincta ssp. australis (A.& V. Grant) Day 

& V. Grant lesser yellowthroat gilia X X

Gilia stellata Heller star gilia X X X X

Linanthus aureus (Nutt.) Greene golden linanthus O

Linanthus bigelovii (Gray) Greene Bigelow’s linanthus X

Phlox tenuifolia E. Nels. Santa Catalina Mountain phlox X X

Polygalaceae Monnina wrightii Gray blue pygmyflower X

Polygala macradenia Gray glandleaf milkwort X X X O

Polygonaceae Chorizanthe brevicornu Torr. brittle spineflower X X O X O

Chorizanthe rigida (Torr.) Torr. & Gray devil’s spineflower X X

Eriogonum abertianum Torr. Abert’s buckwheat X O X X

Eriogonum deflexum Torr. flatcrown buckwheat X O X O

Eriogonum inflatum Torr. & Frém. desert trumpet X X

Eriogonum maculatum Heller spotted buckwheat X X

Eriogonum palmerianum Reveal Palmer’s buckwheat X X X

Eriogonum polycladon Benth. sorrel buckwheat X

Eriogonum thurberi Torr. Thurber’s buckwheat X X

Eriogonum wrightii Torr. ex Benth. bastardsage X O

Eriogonum wrightii var. wrightii Torr. ex Benth. bastardsage X

Portulacaceae Calandrinia ciliata (Ruiz & Pavón) DC. fringed redmaids X X

Cistanthe monandra (Nutt.) Hershkovitz common pussypaws X X X X

Portulaca oleracea L. little hogweed X

Portulaca suffrutescens Engelm. shrubby purslane X

Portulaca umbraticola Kunth wingpod purslane X

Talinum aurantiacum Engelm. orange fameflower X X

Talinum paniculatum (Jacq.) Gaertn. jewels of Opar X X

Primulaceae Androsace occidentalis Pursh western rockjasmine X X O

Pteridaceae Astrolepis cochisensis ssp. cochisensis

(Goodding) Benham & Windham Cochise scaly cloakfern X X O

Astrolepis sinuata (Lag. ex Sw.) Benham & 

Windham ssp. sinuata wavy scaly cloakfern O X X O

Cheilanthes lindheimeri Hook. fairyswords X O

Cheilanthes pringlei Davenport Pringle’s lipfern X X

Cheilanthes wootonii Maxon beaded lipfern X

Cheilanthes wrightii Hook. Wright’s lipfern X X O

Cheilanthes yavapensis Reeves ex Windham graceful lipfern X X

Notholaena standleyi Maxon star cloak fern X O

Pellaea truncata Goodding spiny cliffbrake X

Ranunculaceae Anemone tuberosa Rydb. tuber anemone X O

Delphinium scaposum Greene tall mountain larkspur O X O X O

Myosurus cupulatus S. Wats. Arizona mousetail X X

Thalictrum fendleri Engelm. ex Gray Fendler’s meadow-rue X

Rhamnaceae Condalia warnockii M.C. Johnston Warnock’s snakewood X O

Ziziphus obtusifolia (Hook. ex Torr. & Gray) Gray lotebush X O

Ziziphus obtusifolia var. canescens (Gray) M.C. 

Johnston lotebush O X

Rosaceae Vauquelinia californica (Torr.) Sarg. Arizona rosewood X X

Rubiaceae Galium aparine L. stickywilly X X

Galium proliferum Gray limestone bedstraw O X X O

Galium stellatum Kellogg starry bedstraw X X

Galium stellatum ssp. eremicum (Hilend & Howell) 

Ehrend. starry bedstraw X

Houstonia pusilla Schoepf tiny bluet O

Rutaceae Thamnosma texana (Gray) Torr. rue of the mountains X X O

Salicaceae Populus fremontii S. Wats. Fremont cottonwood X X

Salix gooddingii Ball Goodding’s willow X

Salix irrorata Anderss. dewystem willow X
77

Family Scientific name Common name UA UAH VnD Rea H&G SNP

Scrophulariaceae Castilleja exserta (Heller) Chuang & Heckard exserted Indian paintbrush X

Castilleja exserta ssp. exserta (Heller) Chuang 

& Heckard exserted Indian paintbrush O X O X

Maurandella antirrhiniflora (Humb. & Bonpl. ex 

Willd.) Rothm. roving sailor X

Mimulus guttatus DC. seep monkeyflower X X

Mimulus rubellus Gray little redstem monkeyflower X X

Nuttallanthus texanus (Scheele) D.A. Sutton Texas toadflax O X O X

Penstemon parryi (Gray) Gray Parry’s beardtongue X O X

Penstemon subulatus M.E. Jones hackberry beardtongue X X O

Sairocarpus nuttallianus (Benth. ex A. DC.) D.A. 

Sutton violet snapdragon X X

Stemodia durantifolia (L.) Sw. whitewoolly twintip X X

Veronica peregrina L. neckweed X

Veronica peregrina ssp. xalapensis (Kunth) 

Pennell hairy purslane speedwell X

Selaginellaceae Selaginella arizonica Maxon Arizona spikemoss O X X O

Simaroubaceae Castela emoryi (Gray) Moran & Felger crucifixion thorn O

Simmondsiaceae Simmondsia chinensis (Link) Schneid. jojoba O X X O

Solanaceae Calibrachoa parviflora (Juss.) D’Arcy seaside petunia X X

Datura discolor Bernh. desert thorn-apple X O X

Datura wrightii Regel sacred thorn-apple O O

Lycium andersonii Gray water jacket X X

Lycium andersonii var. wrightii Gray water jacket X

Lycium berlandieri Dunal Berlandier’s wolfberry O X O O

Lycium berlandieri var. longistylum C.L. Hitchc. Berlandier’s wolfberry X X

Lycium exsertum Gray Arizona desert-thorn X X

Lycium fremontii Gray Fremont’s desert-thorn X X

Margaranthus solanaceus Schlecht. netted globecherry X X

Nicotiana obtusifolia var. obtusifolia Mertens & 

Galeotti desert tobacco X O X

Physalis crassifolia Benth. yellow nightshade groundcherry X O X O

Physalis hederifolia Gray ivyleaf groundcherry X

Solanum douglasii Dunal greenspot nightshade X X

Solanum elaeagnifolium Cav. silverleaf nightshade X X

Sterculiaceae Ayenia compacta Rose California ayenia O X

Ayenia filiformis S. Wats. TransPecos ayenia X X O X O

Ayenia microphylla Gray dense ayenia O X O

Hermannia pauciflora S. Wats. Santa Catalina burstwort X X

Tamaricaceae Tamarix ramosissima Ledeb. saltcedar X

Ulmaceae Celtis pallida Torr. spiny hackberry O O X O

Urticaceae Parietaria hespera Hinton rillita pellitory O X O O

Parietaria hespera Hinton var. hespera rillita pellitory X

Parietaria pensylvanica Muhl. ex Willd. Pennsylvania pellitory X X

Verbenaceae Aloysia wrightii Heller ex Abrams Wright’s beebrush X X O

Glandularia gooddingii (Briq.) Solbrig southwestern mock vervain X X X

Verbena neomexicana (Gray) Small hillside vervain X X

Violaceae Hybanthus verticillatus (Ortega) Baill. babyslippers X X

Viscaceae Phoradendron californicum Nutt. mesquite mistletoe O X O X O

Zygophyllaceae Kallstroemia californica (S. Wats.) Vail California caltrop O X

Kallstroemia grandiflora Torr. ex Gray Arizona poppy X X

Kallstroemia parviflora J.B.S. Norton warty caltrop X X

Larrea tridentata (Sessé & Moc. ex DC.) Coville creosote bush O O

Larrea tridentata var. tridentata (Sessé & Moc. ex DC.) 

Coville creosote bush O X

Tribulus terrestris L. puncturevine X O X
78

Appendix B. List of reptiles and amphibians found by University of Arizona Inventory personnel and field method(s) 

used to detect them, Saguaro NP, Tucson Mountain District, 2001 and 2002. 

Family Scientific name Common name Intensive Extensive

Road

surveys Pitfall Incidental

Anura

 Pelobatidae Scaphiopus couchii Couch’s spadefoot toad

 Bufonidae Bufo alvarius Sonoran desert toad X X X

Bufo punctatus red-spotted toad X X X

Bufo cognatus Great Plains toad X

Testudines

 Testudinidae Gopherus agassizii desert tortoisea X X

Squamata

 Gekkonidae Coleonyx variegatus western banded gecko X X X X

 Iguanidae Dipsosaurus dorsalis desert iguana X X X

 Crotaphytidae Crotaphytus nebrius Sonoran collared lizard X

Gambelia wislizenii long-nosed leopard lizard X X

 Phrynosomatidae Holbrookia maculata lesser earless lizard X X

Callisaurus draconoides zebra-tailed lizard X X X X X

Sceloporus magister desert spiny lizard X X X X X

Sceloporus clarkii Clark’s spiny lizard X X X

Uta stansburiana side-blotched lizard X X X X X

Urosaurus ornatus ornate tree lizard X X X

Phrynosoma solare regal horned lizard X X X X

 Teiidae Cnemidophorus sonorae Sonoran spotted whiptail X X

Cnemidophorus tigris western whiptail X X X X X

 Helodermatidae Heloderma suspectum Gila monster X X X X

 Leptotyphlopidae Leptotyphlops humilis western blind snake X X

 Colubridae Masticophis flagellum coachwhip X X X

Masticophis bilineatus Sonoran whipsnake X

Salvadora hexalepis western patch-nosed 

snake X X X X

Pituophis catenifer gopher snake X X X

Arizona elegans glossy snake X

Rhinocheilus lecontei long-nosed snake X X X X

Trimorphodon biscutatus western lyre snake X

Hypsiglena torquata night snake X X

 Elapidae Micruroides euryxanthus Sonoran coral snake X

 Viperidae Crotalus atrox western diamond-backed 

rattlesnake X X X X

Crotalus cerastes Sidewinder X

Crotalus molossus black-tailed rattlesnake X X

Crotalus tigris tiger rattlesnake X X X X

Crotalus scutulatus Mohave rattlesnake X X

Species richness 14 30 15 8 28

a “Species of Concern”, U.S. Fish and Wildlife Service; “Wildlife of Special Concern”, Arizona Game and Fish Department. Data from 

HDMS (2004).
79

Appendix C. List of bird species observed at Saguaro NP, Tucson Mountain District by UA inventory personnel (2001 and 2002) or by other survey efforts or 

lists: Monson and Smith (M&S; 1986), Yensen (YE; 1976), Short (SH; 1996), and Kline (KL; 1998). See text for descriptions of UA survey types. Underlined species are 

neotropical migrants (Rappole 1995) and species in bold-faced type are non-native.

UA survey 

method Species lists Conservation designationa

Order Family Scientific name Common name VCP Noct Incid M&S YE SH KL ESA BLM USFS WSCA APF USFWS

Galliformes Odontophoridae Callipepla gambelii Gambel’s quail 115 X X X X

Ciconiiformes Cathartidae Coragyps atratus black vulture X

Cathartes aura turkey vulture 10 X X X X

Falconiformes Accipitridae Circus cyaneus northern harrier X

Accipiter striatus sharp-shinned hawk X X S

Accipiter cooperii Cooper’s hawk X X

Parabuteo unicinctus Harris’s hawk 9 2 X X X X

Buteo albonotatus zone-tailed hawk 1 X

Buteo jamaicensis red-tailed hawk 6 1 X X X X

Aquila chrysaetos golden eagle 3 7 X X

Falconidae Falco sparverius American kestrel 5 1 X X X

Falco mexicanus prairie falcon 10 1 X

Charadriiformes Charadriidae Charadrius vociferus killdeer X

Columbiformes Columbidae Columba livia rock pigeon X

Zenaida asiatica white-winged dove 331 3 X X X

Zenaida macroura mourning dove 205 4 X X

Columbina inca Inca dove 1 X

Columbina passerina common ground-dove X

Cuculiformes Cuculidae Coccyzus americanus occidentalis yellow-billed cuckoo b X C S WSC P BCC

Geococcyx californianus greater roadrunner 1 X X X

Strigiformes Tytonidae Tyto alba barn owl X X

Strigidae Megascops kennicottii western screech-owl 18 2 X X

Bubo virginianus great horned owl 4 1 X X X X

Athene cunicularia hypugaea burrowing owl X SC S

Micrathene whitneyi elf owl 58 2 X X BCC

Caprimulgiformes Caprimulgidae Chordeiles acutipennis lesser nighthawk 1 15 3 X X

Phalaenoptilus nuttallii common poorwill 1 26 X

Apodiformes Apodidae Chaetura vauxi Vaux’s swift X

Aeronautes saxatalis white-throated swift 37 1 X X

Trochilidae Archilochus alexandri black-chinned hummingbird 1 X

Calypte anna Anna’s hummingbird 1 X

Calypte costae Costa’s hummingbird 10 3 X X P

Stellula calliope calliope hummingbird X

Selasphorus platycercus broad-tailed hummingbird 1

Piciformes Picidae Melanerpes uropygialis Gila woodpecker 308 2 X X X BCC

Sphyrapicus varius yellow-bellied sapsucker X
80

UA survey 

method Species lists Conservation designationa

Order Family Scientific name Common name VCP Noct Incid M&S YE SH KL ESA BLM USFS WSCA APF USFWS

Piciformes Picidae Picoides scalaris ladder-backed woodpecker 9 X X

Colaptes auratus northern flicker X X

Colaptes chrysoides gilded flicker 37 1 X X P BCC

Passeriformes Tyrannidae Contopus cooperi olive-sided flycatcher X SC

Contopus sordidulus western wood-pewee X

Empidonax traillii willow flycatcher X WSC

Empidonax hammondii Hammond’s flycatcher X

Empidonax wrightii gray flycatcher 1 X

Empidonax oberholseri dusky flycatcher X

Empidonax occidentalis or difficilis western flycatcher X X

Sayornis saya Say’s phoebe X X

Myiarchus cinerascens ash-throated flycatcher 126 1 X X X

Myiarchus tyrannulus brown-crested flycatcher 27 1 X X X

Tyrannus verticalis western kingbird 1 X

Laniidae Lanius ludovicianus loggerhead shrike X X X SC S

Vireonidae Vireo bellii Bell’s vireo X X S BCC

Vireo vicinior gray vireo X

Vireo gilvus warbling vireo X

Corvidae Cyanocitta stelleri Steller’s jay X

Aphelocoma californica western scrub-jay 1 4 X

Corvus corax common raven 15 X X

Hirundinidae Progne subis purple martin 33 10 X X X P

Tachycineta bicolor tree swallow X

Tachycineta thalassina violet-green swallow X

Stelgidopteryx serripennis northern rough-winged swallow 1

Petrochelidon pyrrhonota cliff swallow 1

Hirundo rustica barn swallow X X

Remizidae Auriparus flaviceps verdin 141 2 X X X

Troglodytidae Campylorhynchus brunneicapillus cactus wren 161 2 X X X

Salpinctes obsoletus rock wren 8 X X

Catherpes mexicanus canyon wren 41 3 X X

Thryomanes bewickii Bewick’s wren X X

Troglodytes aedon house wren X

Regulidae Regulus calendula ruby-crowned kinglet 1 X X

Sylviidae Polioptila caerulea blue-gray gnatcatcher 3 2 X

Polioptila melanura black-tailed gnatcatcher 64 3 X X X

Turdidae Sialia mexicana western bluebird X

Sialia currucoides mountain bluebird X

Myadestes townsendi Townsend’s solitaire X
81

UA survey 

method Species lists Conservation designationa

Order Family Scientific name Common name VCP Noct Incid M&S YE SH KL ESA BLM USFS WSCA APF USFWS

Passeriformes Turdidae Catharus guttatus hermit thrush 1 X

Turdus migratorius American robin X X

Mimidae Mimus polyglottos northern mockingbird 6 1 X X X

Oreoscoptes montanus sage thrasher X

Toxostoma bendirei Bendire’s thrasher 1 2 X

Toxostoma curvirostre curve-billed thrasher 98 3 X X X

Toxostoma crissale crissal thrasher X BCC

Sturnidae Sturnus vulgaris European starling X X

Bombycillidae Bombycilla cedrorum cedar waxwing X

Ptilogonatidae Phainopepla nitens phainopepla 3 2 X X

Parulidae Vermivora celata orange-crowned warbler 2 3 X

Vermivora ruficapilla Nashville warbler X

Vermivora virginiae Virginia’s warbler X

Vermivora luciae Lucy’s warbler 1 X X P

Dendroica coronata yellow-rumped warbler X X

Dendroica nigrescens black-throated gray warbler 1 1 X X X

Dendroica townsendi Townsend’s warbler X

Dendroica occidentalis hermit warbler X

Oporornis tolmiei MacGillivray’s warbler 1 X

Wilsonia pusilla Wilson’s warbler 2 1 X X

Thraupidae Piranga ludoviciana western tanager 1 X X

Emberizidae Pipilo chlorurus green-tailed towhee 4 3 X

Pipilo maculatus spotted towhee X

Pipilo fuscus canyon towhee 57 X X X

Aimophila carpalis rufous-winged sparrow 15 8 X X X P BCC

Aimophila cassinii Cassin’s sparrow X

Aimophila ruficeps rufous-crowned sparrow 6 X X

Spizella passerina chipping sparrow 2 3 X

Spizella breweri Brewer’s sparrow 21 7 X X

Spizella atrogularis black-chinned sparrow X

Pooecetes gramineus vesper sparrow X

Chondestes grammacus lark sparrow X X

Melospiza lincolnii Lincoln’s sparrow X

Amphispiza bilineata black-throated sparrow 95 1 X X

Amphispiza belli sage sparrow X X

Calamospiza melanocorys lark bunting X

Melospiza melodia song sparrow X

Zonotrichia albicollis white-throated sparrow X

Zonotrichia leucophrys white-crowned sparrow 3 X X
82

UA survey 

method Species lists Conservation designationa

Order Family Scientific name Common name VCP Noct Incid M&S YE SH KL ESA BLM USFS WSCA APF USFWS

Passeriformes Emberizidae Junco hyemalis dark-eyed junco X

Cardinalidae Cardinalis cardinalis northern cardinal 7 X X

Cardinalis sinuatus pyrrhuloxia 67 2 X X X

Pheucticus ludovicianus rose-breasted grosbeak X

Pheucticus melanocephalus black-headed grosbeak 1 X X X

Passerina caerulea blue grosbeak 1

Passerina amoena lazuli bunting 1 X

Passerina versicolor varied bunting 3 3 X

Icteridae Agelaius phoeniceus red-winged blackbird X

Euphagus cyanocephalus Brewer’s blackbird X

Quiscalus mexicanus great-tailed grackle 3

Molothrus aeneus bronzed cowbird X

Molothrus ater brown-headed cowbird 76 2 X X X

Icterus cucullatus hooded oriole X X

Icterus bullockii Bullock’s oriole 4 1 X X

Icterus parisorum Scott’s oriole 12 X X X

Fringillidae Carpodacus mexicanus house finch 76 X X X

Carduelis pinus pine siskin X X

Carduelis psaltria lesser goldfinch 7 X

Passeridae Passer domesticus house sparrow 4 X

a

 ESA = Endangered Species Act; U.S. Fish and Wildlife Service; “SC” = “Species of Concern”; “C” = Candidate for listing. USFS = U.S.D.A. Forest Service, “Sensitive species” (HDMS 2004). 

WSCA = Arizona Game and Fish Department, “Wildlife of Special Concern” (HDMS 2004). APF = Arizona Partners in Flight, “Priority species”; (Latta et al. 1999). U.S. Fish and Wildlife Service, 

“Species of conservation concern” (HDMS 2004).

b

 Unlikely to occur except as rare passage migrant.
83

Appendix D. List of mammals observed at Saguaro NP, Tucson Mountain District by University of Arizona (UA) and Saguaro National Park (SNP) Inventory personnel 

by survey type, 2001-2005 and other efforts. Numbers of observations are not scaled by search effort and should not be used for comparison among species or survey types. 

See Appendix E for additional information on specimen (Spec.) and photographic (Photo) vouchers. Historical data from: Historical specimen records (HSR; Appendix F), Sidner 

and Davis (S&D; 1994), Yensen (YEN;1973), Parmenter (PAR; unpubl. data), and Kline et al (Kea; 1999). Species in bold-faced type are non-native. 

Number of observation by UA/SNP 

survey method

Vouchers from this 

effort

Historical Data/

Species Lists

Order 

 Family Scientific name Common name

Small

mammal

Bat

netting Trailmaster Incidental Photograph Specimen HSR S&D YEN PAR Kea

Chiroptera

 Phyllostomidae Macrotus californicus California leaf-nosed bat 2 1 X

 Vespertilionidae Myotis veliferab cave myotis 11 4 X

Pipistrellus hesperus western pipistrelle 4 X

Eptesicus fuscus big brown bat X

Corynorhinus townsendii pallescensa Townsend’s big-eared bat 1 X

 Procyonidae Procyon lotor northern raccoon 1 1 X

Nasua narica white-nosed coati obsc

Bassariscus astutus ringtail 15 1 X

 Mustelidae Taxidea taxus American badger 9 1 1

 Mephitidae Spilogale gracilis western spotted skunk 4 1

Mephitis mephitis striped skunk 3 1 X

Mephitis macroura hooded skunk 62 1

Conepatus mesoleucus white-backed hog-nosed skunk 6 1

 Canidae Canis familiaris feral dog 3 1 1

Canis latrans coyote 245 1 1 1 X

Urocyon cinereoargenteus common gray fox 582 2 1 X

Vulpes macrotus kit fox 2 1 X

 Felidae Felis catus feral cat 1

Puma concolor azteca mountain lion 7 1 X

Lynx rufus bobcat 36 1 X

Rodentia 

 Sciuridae Spermophilus variegatus rock squirrel 30 1 1 1 X

Spermophilus tereticaudus round-tailed ground squirrel 2 1

Ammospermophilus harrisii Harris’ antelope squirrel 1 17 2 1 X

 Heteromyidae Perognathus amplus taylori Arizona pocket mouse 30 2 X X

Chaetodipus penicillatus Sonoran Desert pocket mouse 39 3 6 X X

Chaetodipus intermedius intermediusa rock pocket mouse 30 X

Chaetodipus baileyi Bailey’s pocket mouse 27 3 X X

Dipodomys merriami Merriam’s kangaroo rat 32 X X

 Muridae Peromyscus eremicus eremicusa cactus mouse 4 3 X

 Peromyscus boylii brush mouse 1d
84

Number of observation by UA/SNP 

survey method

Vouchers from this 

effort

Historical Data/

Species Lists

Order 

 Family Scientific name Common name

Small

mammal

Bat

netting Trailmaster Incidental Photograph Specimen HSR S&D YEN PAR Kea

Rodentia

 Muridae Peromyscus maniculatus deer mouse 1

Mus musculus house mouse X

Onychomys torridus southern grasshopper mouse 2 X X

Neotoma albigula western white-throated woodrat 10 3 X X

Sigmodon arizonae arizonae Arizona cotton rat 1

Lagomorpha

 Leporidae Lepus alleni antelope jackrabbit 22 1

Lepus californicus black-tailed jackrabbit 98 1 1 X

Sylvilagus audubonii desert cottontail 169 1 1 1 X X

Artiodactyla

 Tayassuidae Pecari tajacu collared peccary 327 5 1 2 X

 Cervidae Odocoileus hemionus mule deer 52 3 1 X

a

 U.S. Fish and Wildlife Service “Species of Concern.”

b Bureau of Land Management (BLM) “Sensitive species”

c Coati has been observed by staff only and could be misidentified; see text. 

d

 Brush mouse not confirmed and could be misidentified; see text. 
85

Appendix E. Vertebrate specimen and photograph vouchers collected by University of Arizona or park personnel, 

Saguaro National Park,Tucson Mountain District, 1997–2002. All voucher specimens are located in the University of Arizona 

(AZ) collections. All photographic vouchers are located in the I&M office in Tucson. 

Voucher type Taxon Common Name Collector(s) Collection date AZ collection # Specimen type

Specimen Reptile zebra-tailed lizard James E. Borgmeyer 04/11/01 52697

regal horned lizard Kevin E. Bonine 07/29/02 54441

western whiptail (tiger whiptail) Chris K. Kirkpatrick 04/24/01 53647

coachwhip Larry L. Norris 03/31/01 53642

western patch-nosed snake James E. Borgmeyer 04/14/01 52699

glossy snake Dave B. Prival 10/25/01 53668

long-nosed snake James E. Borgmeyer 04/17/01 52700

variable sandsnake Brian F. Powell 11/03/01 52450

Pam Swantek (Anning) 05/13/97

Sonoran coral snake Mark Holden

western diamond-backed rattlesnake George Bradley 10/04/01 53676

Mammal California leaf-nosed bat Ronnie Sidner 03/28/01 26751 Partial Cranium

cave myotis Ronnie Sidner 05/15/01 26839 Skin and Skull

Ronnie Sidner 01/28/02 26753 Skull

Ronnie Sidner 01/28/02 26754 Skull

Ronnie Sidner 03/28/01 26752 Skull

American badger Jason A. Schmidt 09/30/01 26768 Skull

feral dog Jason A. Schmidt 04/13/01 26780 Skull

coyote Jason A. Schmidt 08/25/01 27027 Skull

feral cat Neil D. Perry 09/26/01 26767 Skull

rock squirrel Jason A. Schmidt 08/23/01 Skin and Skull

Sonoran Desert pocket mouse Jason A. Schmidt 10/02/01 26903 Skull

Jason A. Schmidt 10/01/01 26930 Skull

Jason A. Schmidt 10/02/01 26932 Skull

desert cottontail Neil D. Perry 06/06/01 26748 Skull and Skin

collared peccary Jason A. Schmidt 08/25/01 Skull

Neil D. Perry 04/12/01 26775 Skull

Photograph Amphibian Couch’s spadefoot Dave B. Prival 07/05/01

Sonoran desert toad Dave B. Prival 06/29/01

red-spotted toad Dave B. Prival 07/02/01

Great Plains toad Dave B. Prival 07/31/01

Reptile desert tortoise Dave B. Prival 04/14/01

western banded gecko Dave B. Prival 07/15/01

desert iguana Dave B. Prival 07/17/01

eastern collared lizard Dave B. Prival 04/14/01

long-nosed leopard lizard Dave B. Prival 09/08/01

lesser earless lizard Dave B. Prival 07/16/01

zebra-tailed lizard Dave B. Prival 04/12/01

Clark’s spiny lizard Dave B. Prival 04/14/01

common side-blotched lizard Dave B. Prival 04/12/01

ornate tree lizard Dave B. Prival 04/11/01

regal horned lizard Dave B. Prival 04/14/01

Gila monster Dave B. Prival 04/13/01

western blind snake Dave B. Prival 09/11/01

coachwhip Dave B. Prival 07/05/01

western patch-nosed snake Dave B. Prival 04/13/01

gopher snake Dave B. Prival 07/03/01

glossy snake Dave B. Prival 09/25/01

long-nosed snake Dave B. Prival 04/14/01

western lyre snake Dale S. Turner 07/11/02

night snake Dave B. Prival 07/15/01

western diamond-backed rattlesnake Dave B. Prival 06/29/01

sidewinder Dave B. Prival 07/13/01
86

Voucher type Taxon Common Name Collector(s) Collection date AZ collection # Specimen type

Photograph black-tailed rattlesnake Mike D. Wall 04/17/01

tiger rattlesnake Dave B. Prival 06/29/01

Mojave rattlesnake Dave B. Prival 07/16/01

Bird Gambel’s quail Neil D. Perry 08/27/01

mourning dove Neil D. Perry 08/27/01

greater roadrunner Neil D. Perry 08/27/01

western screech-owl Ronnie Sidner 05/11/01

Mammal cave myotis Ronnie Sidner 05/11/01

western pipistrelle Ronnie Sidner 05/11/01

ringtail Neil D. Perry 04/27/02

American badger Neil D. Perry 04/27/01

western spotted skunk Neil D. Perry 10/03/01

striped skunk Neil D. Perry 10/29/01

hooded skunk Neil D. Perry 09/19/01

white-backed hog-nosed skunk Neil D. Perry 10/17/01

common gray fox Neil D. Perry 08/22/01

bobcat Neil D. Perry 04/27/02

rock squirrel Neil D. Perry 09/19/01

black-tailed jackrabbit Neil D. Perry 09/19/01

collared peccary Neil D. Perry 10/01/01

Appendix F. List of existing voucher specimens collected prior to our inventory effort. See Table 1.1 for list of collections 

queried for these data. 

Taxon Common name Collectiona Collection number Collection date Collector

Amphibian Couch’s spadefoot UA 25626 00/00/68

Sonoran desert toad UA 25623 00/00/68

Reptile desert spiny lizard TTU 6,38 08/06/69 P. Tatano

regal horned lizard NHMLAC 107276

Gila monster NPS 597 05/26/66 E. Pingry

gopher snake UA 31761 00/00/69

western diamond-backed rattlesnakeUCB 206949, 206950 09/01/87 H. W. Greene

sidewinder NPS 573 08/04/66 B. A. Lund

tiger rattlesnake UM 134070, 134071 06/13/70 R. W. Van Devender

Mammal cave myotis NPS 5297, 5686, 5687 05/02/91, 07/01/94, 03/16/93 Sidner

Townsend’s big eared bat UA 1077 10/6/51 J.B. Elder

Arizona pocket mouse UA 16751, 22650 09/17/66, 06/15/71 J. L. Patton, C. B. Robbins

Sonoran Desert pocket mouse UA 22655, 4026-30, 5710, 

25704 06/13/71, 10/6/51 C. B. Robbins, W. G. Swank, J. B. Elder

Bailey’s pocket mouse UA 25948, 26297, 26411 11/04/83, 11/03/83 E. E. Johnson, J. Hazam

deer mouse UA 19605 12/27/71 L. Jacobs

cactus mouse UA 25945, 1196, 5320 11/04/83, 11/23/51 E. E. Johnson, J. B. Elder

Arizona cotton rat NPS 1993 N. Kline

southern grasshopper mouse UA 5321, 18960 11/23/51, 3/2/70 J. B. Elder, J.C. Geest

western white-throated woodrat UA 1260-61, 25953 11/6/51, 11/4/83 W. G. Swank, E. E. 

Johnson

a

 NHMLAC = Natural History Museum of Los Angeles County; NPS = National Park Service, Western Archaeological Conservation Center ; 

TTU = Texas Tech University; UA = University of Arizona Collections; UCB = Museum of Vertebrate Zoology, University of California; UM = 

University of Michigan.
87

Appendix G. Percent composition (Comp.) and cover from point-intercept transects, by height category, 

Saguaro NP, Tucson Mountain District, 2001. See text for description of calculations of percent composition 

(“Comp.”) and cover. 

0 - .5 m .5 - 2m 2 - 4m >4m

Transect Species

%

Comp.

%

Cover

%

Comp.

%

Cover

%

Comp.

%

Cover

%

Comp.

%

Cover

204 Jacobinia candicans 0.2 0.1

Asclepias lemmonii 0.2 0.1

Ambrosia ambrosioides 0.3 0.2 0.3 0.1

Ambrosia deltoidea 17.0 10.4 3.7 1.3

Aster leucelene 0.2 0.1

Brickellia coulteri 0.7 0.4

Dyssodia porophylloides 0.8 0.5

Encelia farinosa 1.1 0.7 0.6 0.2

Hymenoclea salsola 8.5 5.2 8.0 2.8 1.4 0.1

Machaeranthera gracilis 0.2 0.1

Machaeranthera parviflora 0.2 0.1 0.3 0.1

Psilostrophe cooperi 0.2 0.1

Uropappus linearifolius 0.2 0.1

Zinnia acerosa 0.5 0.3

Pennellia micrantha 0.5 0.3 1.7 0.6 2.7 0.2

Opuntia acanthocarpa 3.9 2.4 4.6 1.6

Opuntia leptocaulis 1.3 0.8 0.6 0.2

Opuntia phaeacantha 7.5 4.6 9.8 3.4

Opuntia versicolor 0.3 0.2 0.6 0.2

Atriplex canescens 0.2 0.1

Euphorbia capitellata 0.2 0.1

Euphorbia sp. 0.2 0.1

Jatropha cardiophylla 0.8 0.5 1.7 0.6

Acacia constricta 3.6 2.2 13.5 4.7

Acacia greggii 0.5 0.3 0.6 0.2

Caesalpinia gilliesii 0.2 0.1 4.1 0.3

Calliandra eriophylla 10.1 6.2 1.1 0.4

Dead olneya tesota 0.9 0.3 2.7 0.2

Olneya tesota 1.5 0.9 5.7 2.0 23.3 1.7

Parkinsonia microphylla 2.9 1.8 17.0 5.9 35.6 2.6

Prosopis velutina 0.3 0.2 3.4 1.2 5.5 0.4

Fouquieria splendens 0.9 0.3 4.1 0.3

Krameria grayi 1.6 1.0 0.3 0.1

Krameria sp. 0.8 0.5

Dichelostemma pulchellum 0.5 0.3

Janusia gracilis 10.8 6.6 9.8 3.4 1.4 0.1

Abutilon incanum 0.5 0.3 0.6 0.2

Hibiscus coulteri 0.6 0.2

Sphaeralcea laxa 0.2 0.1

Commicarpus scandens 1.3 0.8 0.3 0.1

Forestiera shrevei 0.3 0.1

Menodora scabra 0.5 0.3

Passiflora mexicana 0.5 0.3 2.3 0.8 6.8 0.5

Alopecurus carolinianus 0.2 0.1

Aristida ternipes 0.2 0.1

Bouteloua chondrosioides 2.8 1.7

Cortaderia selloana 0.5 0.3 0.6 0.2

Digitaria californica 1.3 0.8 0.3 0.1

Heteropogon contortus 0.2 0.1 0.3 0.1

Muhlenbergia polycaulis 0.3 0.2

Muhlenbergia porteri 1.6 1.0
88

0 - .5 m .5 - 2m 2 - 4m >4m

Transect Species

%

Comp.

%

Cover

%

Comp.

%

Cover

%

Comp.

%

Cover

%

Comp.

%

Cover

204 Phalaris canariensis 0.3 0.2 0.9 0.3 1.4 0.1

Hedyotis crassifolia 0.3 0.2

Selaginella arizonica 6.2 3.8

Castela emoryi 0.2 0.1

Lycium berlandieri 0.7 0.4 1.1 0.4

Celtis pallida 1.8 1.1 3.7 1.3 5.5 0.4

Phoradendron californicum 0.5 0.3 1.4 0.5 5.5 0.4

Larrea tridentata 1.3 0.8 2.3 0.8

212 Carlowrightia arizonica 1.7 1.0

Jacobinia candicans 1.0 0.3

Ambrosia deltoidea 1.1 0.7

Baileya multiradiata 0.6 0.3

Bebbia juncea 1.0 0.3

Encelia farinosa 3.9 2.3 3.8 1.3

Trixis californica 2.2 1.3

Carnegia gigantea 0.6 0.3

Opuntia acanthocarpa 2.2 1.3 3.8 1.3

Opuntia arbuscula 2.2 1.3 1.0 0.3

Opuntia phaeacantha 5.1 3.0 3.8 1.3

Ditaxis sp. 0.6 0.3

Jatropha cardiophylla 2.2 1.3 3.8 1.3

Acacia constricta 1.7 1.0 5.8 2.0

Acacia greggii 3.4 2.0 6.7 2.3 7.7 0.3

Calliandra eriophylla 1.7 1.0

Coursetia microphylla 5.8 2.0 7.7 0.3

Dead Parkinsonia microphylla 0.6 0.3

Dead Parkinsonia microphylla 1.0 0.3

Parkinsonia microphylla 3.9 2.3 25.0 8.7 69.2 3.0

Dead Fouquieria splendens 0.6 0.3 1.0 0.3

Fouquieria splendens 1.1 0.7 5.8 2.0 15.4 0.7

Janusia gracilis 12.4 7.3 8.7 3.0

Abutilon incanum 3.9 2.3 1.9 0.7

Hibiscus denudatus 4.5 2.7

Allionia incarnata 0.6 0.3

Aristida ternipes 0.6 0.3

Heteropogon contortus 0.6 0.3

Muhlenbergia porteri 1.7 1.0

Poa sp. 0.6 0.3

Tridens muticus 0.6 0.3

Notholaena sinuata 2.8 1.7

Selaginella arizonica 26.4 15.7

Simmondsia chinensis 5.1 3.0 8.7 3.0

Lycium sp. 2.2 1.3 8.7 3.0

Celtis pallida 1.0 0.3

Larrea tridentata 0.6 0.3 1.9 0.7

213 Ambrosia ambrosioides 1.0 0.3

Ambrosia deltoidea 51.0 16.7 1.5 0.3

Brickellia simplex 1.5 0.3

Encelia farinosa 2.0 0.7

Hymenoclea salsola 5.1 1.7 3.1 0.7

Opuntia acanthocarpa 1.0 0.3 1.5 0.3

Opuntia arbuscula 1.0 0.3 3.1 0.7

Opuntia phaeacantha 3.1 1.0 7.7 1.7 4.0 0.3

Canotia holacantha 1.0 0.3 3.1 0.7
89

0 - .5 m .5 - 2m 2 - 4m >4m

Transect Species

%

Comp.

%

Cover

%

Comp.

%

Cover

%

Comp.

%

Cover

%

Comp.

%

Cover

213 Jatropha cardiophylla 2.0 0.7 4.6 1.0

Acacia constricta 3.1 1.0 10.8 2.3 4.0 0.3

Calliandra eriophylla 5.1 1.7 1.5 0.3

Olneya tesota 4.1 1.3 12.3 2.7 28.0 2.3

Parkinsonia microphylla 4.1 1.3 24.6 5.3 64.0 5.3 100.0 1.3

Fouquieria splendens 1.0 0.3 4.6 1.0

Krameria grayi 5.1 1.7 3.1 0.7

Krameria sp. 1.0 0.3 1.5 0.3

Janusia gracilis 3.1 1.0 6.2 1.3

Abutilon incanum 1.0 0.3 1.5 0.3

Selaginella arizonica 3.1 1.0

Lycium sp. 2.0 0.7 1.5 0.3

Larrea tridentata 3.1 0.7

238 Ambrosia deltoidea 11.5 8.0 2.5 1.0

Brickellia coulteri 1.7 0.7

Encelia farinosa 17.7 12.3 15.0 6.0

Porophyllum gracile 0.5 0.3 0.8 0.3

Trixis californica 1.0 0.7 1.7 0.7

Arabis eremophila 0.5 0.3

Carnegia gigantea 3.3 0.3

Opuntia acanthocarpa 0.5 0.3 0.8 0.3

Opuntia arbuscula 0.5 0.3

Ephedra viridis 1.0 0.7 1.7 0.7

Calliandra eriophylla 4.3 3.0

Olneya tesota 2.4 1.7 13.3 5.3 33.3 3.3

Parkinsonia microphylla 6.7 4.7 39.2 15.7 63.3 6.3

Fouquieria splendens 0.5 0.3 0.8 0.3

Krameria grayi 0.5 0.3

Janusia gracilis 4.3 3.0 3.3 1.3

Herissantia crispa 0.5 0.3

Sphaeralcea ambigua 0.5 0.3

Aristida adscensionis 3.8 2.7

Aristida ternipes 1.9 1.3

Bouteloua chondrosioides 0.5 0.3

Trichachne californica 1.4 1.0

Trisetum interruptum 0.5 0.3

Selaginella arizonica 23.4 16.3

Lycium sp. 4.3 3.0 10.8 4.3

Celtis pallida 0.5 0.3 0.8 0.3

Larrea tridentata 1.9 1.3 6.7 2.7

239 Ambrosia deltoidea 65.7 23.0 4.2 1.0

Mammillaria microcarpa 1.0 0.3

Mammillaria thornberi 1.0 0.3

Opuntia acanthocarpa 2.9 1.0 11.3 2.7

Opuntia arbuscula 4.8 1.7 1.4 0.3

Opuntia fulgida 1.9 0.7 7.0 1.7

Opuntia phaeacantha 2.9 1.0 14.1 3.3

Jatropha cardiophylla 1.4 0.3

Acacia greggii 1.4 0.3

Dead Parkinsonia microphylla 1.0 0.3 1.4 0.3

Olneya tesota 1.0 0.3 2.8 0.7

Parkinsonia microphylla 2.9 1.0 19.7 4.7 90.9 3.3

Janusia gracilis 1.4 0.3

Muhlenbergia porteri 3.8 1.3

Larrea tridentata 11.4 4.0 33.8 8.0
90

Family Species 204 212 213 238 239

Acanthaceae

Carlowrightia arizonica X X

Anacardiaceae

Rhus trilobata X X X

Apiaceae

Bowlesia incana X X

Daucus pusillus X X X X X

Spermolepis echinata X

Asteraceae

Adenophyllum 

porophylloides X X

Ambrosia ambrosioides X X

Ambrosia deltoidea X X X X

Ambrosia psilostachya X

Antheropeas lanosum X X X

Baileya multiradiata X

Brickellia coulteri X

Calycoseris wrightii X X

Chaenactis carphoclinia X

Encelia farinosa X X X

Erigeron sp. X

Filago californica X X X

Filago depressa X

Hymenoclea salsola X X

Machaeranthera gracilis X

Malacothrix clevelandii X

Parthenium incanum X

Porophyllum gracile X

Rafinesquia californica X X X X

Senecio flaccidus X

Trixis californica X X

Uropappus lindleyi X X

Zinnia acerosa X X X

Boraginaceae

Amsinckia menziesii X X X

Cryptantha barbigera X

Cryptantha decipiens X

Cryptantha fendleri X

Cryptantha pterocarya X X X X X

Cryptantha sp. X

Pectocarya platycarpa X

Pectocarya recurvata X X X X

Brassicaceae

Descurainia pinnata X X X

Descurainia sp. X

Draba cuneifolia X X X X

Guillenia lasiophylla X

Lepidium lasiocarpum X X X X

Sisymbrium altissimum X X

Sisymbrium irio X

Streptanthus carinatus X

Thysanocarpus curvipes X X X

Family Species 204 212 213 238 239

Cactaceae

Carnegia gigantea X X X X

Echinocereus fendleri X X X

Ferocactus wislizeni X X X X

Mammillaria grahamii X X X

Mammillaria sp. X

Mammillaria thornberi X

Opuntia acanthocarpa X X X X

Opuntia arbuscula X X

Opuntia engelmannii X X

Opuntia fulgida X X

Opuntia leptocaulis X X X X

Opuntia phaeacantha X X X X

Opuntia sp. X

Campanulaceae

Nemacladus glanduliferus X X X

Caryophyllaceae

Loeflingia squarrosa X X

Silene antirrhina X X X

Chenopodiaceae

Atriplex canescens X

Chenopodium sp. X X X

Convolvulaceae

Ipomoea sp. X

Crassulaceae

Crassula connata X X

Ephedraceae

Ephedra trifurca X

Euphorbiaceae

Argythamnia neomexicana X

Euphorbia sp. X

Jatropha cardiophylla X X X

Fabaceae

Acacia constricta X X X

Acacia greggii X

Astragalus didymocarpus X

Astragalus lentiginosus X

Astragalus nuttallianus X X X

Calliandra eriophylla X X

Lotus humistratus X

Lupinus concinnus X X X

Lupinus sparsiflorus X X

Marina calycosa X

Marina parryi X

Olneya tesota X X X

Parkinsonia microphylla X X X X X

Prosopis velutina X

Fouquieriaceae

Fouquieria splendens X

Geraniaceae

Erodium cicutarium X X

Erodium texanum X

Appendix H. Presence of plant species at modified-Whitaker vegetation plots, by vegetation community and plot 

number, Saguaro NP, Tucson Mountain District, 2001.
91

Family Species 204 212 213 238 239

Hydrophyllaceae

Nama hispidum X

Phacelia distans X X X X

Pholistoma auritum X

Lamiaceae

Salvia columbariae X X X

Liliaceae

Calochortus kennedyi X

Dichelostemma capitatum X X

Loasaceae

Mentzelia sp. X

Malpighiaceae

Janusia gracilis X X X

Malvaceae

Abutilon incanum X X

Herissantia crispa X X X X

Hibiscus denudatus X

Sphaeralcea ambigua X

Sphaeralcea laxa X

Nyctaginaceae

Allionia incarnata X

Boerhavia coccinea X

Boerhavia scandens X

Oleaceae

Menodora scabra X X

Onagraceae

Camissonia 

chamaenerioides X X X

Oenothera primiveris X

Oenothera sp. X

Papaveraceae

Eschscholzia californica X

Plantaginaceae

Plantago patagonica X X X X

Poaceae

Aristida adscensionis X X X

Aristida californica X

Bouteloua aristidoides X X

Bouteloua curtipendula X

Bouteloua trifida X

Bromus carinatus X

Dasyochloa pulchella X

Digitaria californica X X

Family Species 204 212 213 238 239

Poaceae

Muhlenbergia porteri X X X X

Poa bigelovii X X X X

Schismus arabicus X X

Schismus barbatus X X

Tridens muticus X

Vulpia octoflora X X X X X

Polemoniaceae

Eriastrum diffusum X X X X X

Gilia sp. X X X

Polygalaceae

Polygala macradenia X

Polygonaceae

Chorizanthe brevicornu X

Portulacaceae

Cistanthe monandra X

Pteridaceae

Astrolepis sinuata X

Ranunculaceae

Delphinium scaposum X

Rubiaceae

Galium proliferum X

Scrophulariaceae

Castilleja exserta X

Mimulus rubellus X

Nuttallanthus texanus X

Selaginellaceae

Selaginella arizonica X X

Simmondsiaceae

Simmondsia chinensis X

Solanaceae

Lycium berlandieri X X X

Physalis hederifolia X

Sterculiaceae

Ayenia compacta X

Ayenia microphylla X

Ulmaceae

Celtis pallida X X X

Parietaria hespera X

Viscaceae

Phoradendron californicum X X X X

Zygophyllaceae

Larrea tridentata X X X
92

Appendix I. Detail of small mammal trapping effort at Saguaro NP, Tucson Mountain District, 2001 and 2002. Data 

from this table are summarized in Table 6.3. In some cases plot group for random plots (those with numbers) included 

non-random transects set in areas near to the random grids. 

Focal point Plot name Grid Visit number Month Year Number of nights trapped Number of traps set

Grid

layout

Trap

spacing (m)

212 212 17/18 1 4 2001 2 42 3 X 7 16.7

3/4 1 4 2001 2 42 3 X 7 16.7

9/10 1 4 2001 2 42 3 X 7 16.7

SSW 09 1 1 4 2001 2 40 Preferential

213 213 17 1 5 2001 3 63 3 X 7 16.7

3 1 5 2001 3 63 3 X 7 16.7

9 1 5 2001 3 63 3 X 7 16.7

17 2 9 2001 2 50 5 X 5 12.5

3 2 9 2001 2 50 5 X 5 12.5

9 2 9 2001 2 50 5 X 5 12.5

SSW X 1 9 2001 2 40 10 X 2

238 238 10 1 6 2001 3 75 5 X 5 12.5

18 1 6 2001 3 75 5 X 5 12.5

3 1 6 2001 3 75 5 X 5 12.5

239 239 17 1 4 2001 3 63 3 X 7 16.7

3 1 4 2001 3 63 3 X 7 16.7

9 1 4 2001 3 63 3 X 7 16.7

17 2 10 2001 2 50 5 X 5 12.5

3 2 10 2001 2 50 5 X 5 12.5

9 2 10 2001 2 50 5 X 5 12.5

SSW 07 1 1 4 2001 3 12 Preferential

SSW 08 1 1 4 2001 3 12 Preferential

SSW Q 1 1 10 2001 2 40 10 X 2 15

Kinney Road SSW 01 1 1 6 2001 2 56 7 X 4

SSW 02 1 1 6 2001 4 100 5 X 5 12.5

SSW 03 1 1 6 2001 3 75 5 X 5 12.5

Sendario SSW 04 1 1 6 2001 3 75 5 X 5 12.5

SSW 05 1 1 6 2001 2 50 5 X 5 12.5

SSW 06 1 1 6 2001 2 50 5 X 5 12.5

Appendix J. Summary of field research for bats, Saguaro NP, Tucson Mountain District, 

2001 and 2002. See text for explanation of net hours calculations. 

Type of 

investigation Location Year

Month/ 

 day

Visit 

number

Total time 

(hours)

Total net 

length (m)

Net 

hours

Roost Gould Mine 2001 03/28 1

2002 07/23 2

Wild Horse Mine 2002 2/27 1

Yuma Mine 2002 1/28 1

Netting Dobe Wash Tank 2001 05/15 1 3.5 5 17.5

Javelina Wash Tank 2001 05/11 1 4.8 5 24.2
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