# Risks of Chlorophacinone Use on Black Tailed Prairie Dogs to Federally Endangered and Threatened Species

Pesticide Effects Determinations

PC Code: 067707

CAS Number: 3691-35-8

Environmental Fate and Effects Division Office of Pesticide Programs Washington, D.C. 20460

September 29, 2010

Primary Authors: Andrew Shelby, Physical Scientist Melissa Grable, Biologist

Secondary Review: Donna Randall, Senior Scientist

Acting Branch Chief, Environme ntal Risk Assessment Branch 2 Jean Holmes, DVM MPH

Senior Science Advisor, Enviro nmental Risk Assessment Branch 6 William P. Eckel, Ph.D.

1

## Acknowledgement

We would like to acknowledge the contributions of Garland Waleko and Nathan Miller in compiling detailed life history informati on on many of the threatened and endangered species. Additionally, the EFED Litigation Steering Committee has provided invaluable guidance toward achieving greater consistency in format and content between chemicals being assessed. Finally we would like to acknowledge members of the review panel for their careful review of this document. The members of the review panel for this assessment were Shannon Borges, Bill Jacobs, Alicia Korol, Ed Odenkirchin, and Ingrid Sunzenauer.

2

# Table of Contents

1. EXECUTIVE SUMMARY ............................................................................. 11

1.1. P URPOSE OF 

### A SSESSMENT 

### ....................................................................................11

1.2. S COPE OF 

### A SSESSMENT 

### ........................................................................................11

1.2.1. Use Assessed ..............................................................................................11

1.2.2. Environmental Fate Properties of Chlorophacinone ..................................12 1.2.3. Evaluation of Degradates and Stressors of Concern..................................12

1.3. A SSESSMENT 

### P ROCEDURES 

### ..................................................................................13

1.3.1. Exposure Assessment .................................................................................13

1.3.2. Toxicity Assessment ..................................................................................14

1.3.3. Measures of Risk ........................................................................................15

1.4. S UMMARY OF 

### C ONCLUSIONS 

### ...............................................................................15

2. PROBLEM FORMULATION ....................................................................... 25

2.1. P URPOSE 

### ..............................................................................................................25

2.2. S COPE 

### ..................................................................................................................26

2.2.1. Evaluation of Degradates ...........................................................................27

2.2.2. Evaluation of Mixtures ..............................................................................27

2.3. P REVIOUS 

### A SSESSMENTS 

### .....................................................................................27

2.4. E NVIRONMENTAL 

### F ATE 

### P ROPERTIES 

### ...................................................................28

2.4.1. Environmental Transport Mechanisms ......................................................29

2.4.2. Mechanism of Action .................................................................................30

2.4.3. Use Characterization ..................................................................................30

2.5. A SSESSED 

### S PECIES 

### ...............................................................................................32

2.5.1. Consideration of Fede rally Listed Plants ...................................................49

2.6. D ESIGNATED 

### C RITICAL 

### H ABITAT 

### .........................................................................50

2.7. A CTION 

### A REA AND 

### LAA E FFECTS 

### D ETERMINATION 

### A REA 

### .................................53

2.7.1. Action Area ................................................................................................53

2.7.2. MA Effects Determination Area ................................................................54

2.8. A SSESSMENT 

### E NDPOINTS AND 

### M EASURES OF 

### E COLOGICAL 

### E FFECT 

### ....................56

2.8.1. Assessment Endpoints ...............................................................................56

2.8.2. Assessment Endpoints for Designated Critical Habitat .............................59

2.9. C ONCEPTUAL 

### M ODEL 

### ..........................................................................................59

2.9.1. Risk Hypotheses .........................................................................................59

2.9.2. Diagram ......................................................................................................60

2.10. A NALYSIS 

### P LAN 

### ...................................................................................................61

2.10.1. Measures of Exposure ................................................................................61

2.10.2. Measures of Effect .....................................................................................62

2.10.3. Data Gaps ...................................................................................................62

3. EXPOSURE ASSESSMENT .......................................................................... 63

3.1. L ABEL 

### A PPLICATION 

### R ATES AND 

### I NTERVALS 

### ......................................................63

3.2. A QUATIC 

### E XPOSURE 

### A SSESSMENT 

### ......................................................................64

3.2.1. Aquatic Exposure in Previous Assessment ................................................64

3

### 3.3. T ERRESTRIAL 

### E XPOSURE 

### A SSESSMENT 

### ................................................................64

3.3.1. Ingestion Rate Determination ....................................................................64

3.3.2. Food Intake Assumptions Releva nt to Terrestrial Exposure .....................65

4. EFFECTS ASSESSMENT .............................................................................. 68

4.1. E COTOXICITY 

### S TUDY 

### D ATA 

### S OURCES 

### .................................................................69

4.2. T OXICITY OF 

### C HLOROPHACINONE TO 

### T ERRESTRIAL 

### O RGANISMS 

### ........................70

4.2.1. Toxicity to Birds ........................................................................................71

4.2.2. Toxicity to Mammals .................................................................................73

4.2.3. Toxicity to Terrestrial Invertebrates ..........................................................74

4.3. I NCIDENT 

### D ATABASE 

### R EVIEW 

### .............................................................................78

4.3.1. Terrestrial Incidents ...................................................................................78

4.4. U SE OF 

### P ROBIT 

### S LOPE 

### R ESPONSE 

### R ELATIONSHIP TO 

### P ROVIDE 

### I NFORMATION ON

THE 

### E NDANGERED 

### S PECIES 

### L EVELS OF 

### C ONCERN 

### ...............................................78

5. RISK CHARACTERIZATION ...................................................................... 79

5.1. R ISK 

### E STIMATION 

### ................................................................................................79

5.1.1. Risk to Birds and Herptiles ........................................................................80

5.1.2. Risk to Mammals .......................................................................................82

5.1.3. Risk to Terrestrial Invertebrates .................................................................84

5.1.4. Primary Constituent Elements of Designated Critical Habitat ..................84

5.2. R ISK 

### D ESCRIPTION 

### ...............................................................................................85

5.2.1. Direct Effects to Listed Species .................................................................98

5.2.2. Indirect Effects to Listed Species ............................................................107

5.2.3. Modification of Designa ted Critical Habitat ............................................108

5.3. E FFECTS 

### D ETERMINATIONS 

### S UMMARY 

### ..............................................................108

5.3.1. Addressing the Risk Hypotheses .............................................................109

6. UNCERTAINTIES ........................................................................................ 109

6.1. E XPOSURE 

### A SSESSMENT 

### U NCERTAINTIES 

### ..........................................................109

6.1.1. Maximum Use Scenario ...........................................................................109

6.1.2. Usage Uncertainties .................................................................................109

6.2. E FFECTS 

### A SSESSMENT 

### U NCERTAINTIES 

### .............................................................110

6.2.1. Data Gaps and Uncertainties ....................................................................110

6.2.2. Carcass Residue Concentration ................................................................110

6.2.3. Sublethal Effects ......................................................................................110

7. RISK CONCLUSIONS ................................................................................. 111

8. REFERENCES ............................................................................................... 120

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# Appendices

Appendix A. Maps Showing the Overlap of the Initial Area of C oncern and the Species

Habitat and Occurrence Sections Appendix B. Risk Quotient (RQ) Method and Levels of Concern (LOCs) Appendix C. Estimation of Upper-bound Aquatic Exposure Appendix D. Literature Submitted During the Comment Period for “Receipt of Petition Requesting EPA to Suspend the Regi stration of Rozol Prairie Dog Bait and Cancel Certain Applicati on Sites” (EPA-HQ-OPP-2009-0684-0001) Appendix E. Summary of Ecotoxicity Data Appendix F. Bibliography of ECOTOX Open Literature Appendix G. Accepted ECOTOX Data Ta ble (sorted by effect) and Bibliography Appendix H. The HED Chapter of the Re registration Eligibility Decision Document (RED) for Rodenticide Cluster Appendix I. Summary of Chlorophacinone Incidents Appendix J. Calculation of Avian RQs using LD 50 

### data



# Attachments

Attachment I: Status and Life Histor y for the Threatened and Endangered Species for which a May Affect Determination was made

5

# List of Tables

Table 1.1 Effects Determination Summary for Effects of Chlorophacinone to 21 Endangered Species. ........................................................................................ 17

Table 1.2. Effects Determina tion Summary for the Critical Habitat Impact Analysis .... 22 Table 2.1 Physical-chemical Properties of chlorophacinone ........................................... 29 Table 2.2 Summary of Current Distribution, Habitat Requirements, and Life History Information for Listed Speci es that May be Affected. ..................................... 33 Table 2.3 Designated Critical Habitat PCEs.................................................................... 50 Table 2.4 Taxa Used in the Analyses of Direct Effects from Primary (Bait) and Secondary Exposure for the Listed Species that May be Affected .................. 56 Table 2.5 Taxa Used in the Analyses of Indi rect Effects for the Li sted Species that May

be Affected....................................................................................................... 57 Table 2.6 Taxa and Assessment Endpoints Used to Evaluate the Potential for Use of Chlorophacinone to Result in Direct and I ndirect Effects to the Listed Species or Modification of Critical Habitat that May be Affected ............................... 58 Table 3.1 Calculation of chlorophacinone inta ke for birds and herptiles using most conservative secondary exposure scenario ....................................................... 65 Table 3.2 Calculation of chlorophacinone inta ke for mammals using most conservative secondary exposure scenario ............................................................................ 66 Table 3.3 Chlorophacinone Residue Levels in Primary Consumers ............................... 67 Table 4.1. Toxicity Profile for Chlorophacinone ............................................................. 70 Table 4.2 Secondary Hazards of Chlor ophacinone to Birds in Laboratory Studies ........ 71 Table 4.3 Secondary Hazards of Chlorophacinone to Mammals in Laboratory Studies . 73

Table 4.4 Evaluation of the Terres trial Invertebrate Reproduction Study. ...................... 77 Table 5.1 Summary of RQ Values for Avian Species. .................................................. 80 Table 5.2 Calculation of Ingestion Rate and Adjusted LD 50 

### for mammals ..................... 82 Table 5.3 Summary of RQ Values for Mammalian Species. .. ....................................... 83 Table 5.4. Risk Estimation Summary for Chlorophacinone ............................................ 86

Table 5.5. Table 5.5 Risk Estimation Summ ary for Chlorophacinone - Effects to Designated Critical Habitat (PCEs) ................................................................. 91 Table 7.1 Effects Determination Summary for Effects of Chlorophacinone to 21 Endangered Species. ...................................................................................... 112

Table 7.2. Effects Determina tion Summary for the Critical Habitat Impact Analysis .. 117

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# List of Figures

Figure 2.1. Chlorophacinone use area for BTPDs ........................................................... 31 Figure 2.2. Initial area of con cern, or “footprint” of poten tial use, for chlorophacinone

use to control BTPDs. ...................................................................................... 55 Figure 2.3 Conceptual model depicting st ressors, exposure pathways, and potential effects to terrestrial organisms from the use of chlorophacinone on BTPDs. . 60

7

### List of Commonly Used Abbreviations and Nomenclature

oC Symbol for “degrees Celsius”

a.i. Active Ingredient

AIMS Avian Monitoring Information System

Acc# Accession Number

Amu Atomic Mass Unit

BCF Bioconcentration Factor

BEAD Biological and Econom ic Analysis Division

BTPD Black tailed prairie dog

Bw Body Weight

CI Confidence Interval

CL Confidence Limit

EC 50 

### 50% (or Median) Effect Concentration

ECOTOX EPA managed databa se of Ecotoxicology data

EEC Estimated Environmental Concentration

EFED Environmental Fa te and Effects Division

e.g

. Latin exempli gratia (“for example”)

EIM Environmental Information Management System

et al. Latin et alii (“and others”)

etc. Latin et cetera (“and the rest” or “and so forth”)

FIFRA Federal Insecticide Fungicide and Rodenticide Act

FQPA Food Quality Protection Act

Ft Feet

g/day Grams per day

GENEEC Generic Estimated E xposure Concentration model

i.e

. Latin for id est (“that is”)

Kg Kilogram(s)

Km Kilometer(s)

Kd Solid-water Distribution Coefficient

KF Freundlich Solid-Water Distribution Coefficient

K OC 

### Organic-carbon Partition Coefficient

K OW 

### Octanol–water Partition Coefficient

LAA Likely to Adversely Affect

lb a.i./A Pound(s) of ac tive ingredient per acre

LC 50 

### 50% (or Median) Lethal Concentration

8

### LD 50 

### 50% (or Median) Lethal Dose

LOAEC Lowest Observable A dverse Effect Concentration

LOAEL Lowest Observable Adverse Effect Level

LOC Level of Concern

LOD Level of Detection

LOQ Level of Quantitation

M Meter(s)

MA May Affect

Mg Milligram(s)

mg/kg Milligrams per kilogram (equivalent to ppm)

mg/L Milligrams per liter (equivalent to ppm)

mL/g Milliliters per gram

Mi Mile(s)

mmHg Millimeter of mercury

MRID Master Record Identification Number

MW Molecular Weight

n/a Not applicable

NAWQA National Water Quality Assessment

NCOD National Contaminant Occurrence Database

NE No Effect

NLAA Not Likely to Adversely Affect

NOAEC No Observable Adverse Effect Concentration

NOAEL No Observable Adverse Effect Level

NOEC No Observable Effect Concentration

OCSPP Office of Chemical Safety and Pollution Prevention

OPP Office of Pesticide Programs

ORD Office of Resear ch and Development

PCE Primary Constituent Element

ppb Parts per Billion (equivale nt to μg/L or μg/kg)

ppm Parts per Million (equivale nt to mg/L or mg/kg)

PRD Pesticide Re-Evaluation Division

RQ Risk Quotient

SLN Special Local Need

TGAI Techinical grade active ingredient

USDA United States Department of Agriculture

USEPA United States Environmental Protection Agency

9

### USFWS United States Fish and Wildlife Service

USGS United States Geological Survey

Wt Weight

10

### 1. Executive Summary

1.1. Purpose of Assessment

The purpose of this assessment is to evaluate potential direct and indir ect effects on federally listed threatened and endangered (listed) species and potential e ffects to designated critical habitat, arising from FIFRA regulatory actions regarding use of chlo rophacinone to control black-tailed prairie dogs (BTPDs). This assessm ent was completed in accordance with the U.S. Fish and Wildlife Service (USFWS) and Na tional Marine Fisheries Service (NMFS) Endangered Species Consultation Handbook (USFWS/NMFS, 1998), procedures outlined in the Agency’s Overview Document (USEPA, 2004a). This ecological risk assessment and effects determination is conducted specific to Rozol Prairie Dog Bait (EPA Reg. No. 7173-286) to address potential product-specific ri sks raised in pending litigation 1



### .

1.2. Scope of Assessment

1.2.1. Use Assessed

Chlorophacinone is an anticoagulant rodenticid e. Chlorophacinone end-use products include tracking powder, bait blocks, pellet ed baits, and grain baits. Chlo rophacinone is used to control house mice, Norway rats, roof rats, pocket gophe rs, voles, ground squirrels, mountain beavers, jack rabbits, wood rats, chipmunks, deer mice a nd BTPDs. This assessment addresses the one chlorophacinone end-use product regi stered for use to control BTPDs. This use is the federal

action evaluated in this assessment. This ch lorophacinone product, Rozol Prairie Dog Bait (EPA registration number 7173-286), is fo rmulated as a loose grain bait with a concentration of 50 mg a.i./kg-bait active ingredient (a.i.) chlorophacinone and is only permitted for use on BTPDs in Colorado, Kansas, Montana, Nebraska, New Mexi co, North Dakota, Oklahoma, South Dakota, Texas and Wyoming. The bait is applied by hand at a rate of 1⁄4 cup (53 grams) of bait, at least 6

inches down into the active BTPD burrows. Base d on the assessed label, two carcass searches are to occur after applic ation, the first being 5 to 10 days post-applicat ion and the second being 14-21 days post-application. Primary and second ary exposure to non-target animals is possible based on this use pattern. If all active BTPD burrows receive the application, the effective application rate is 0.00058 lbs a. i./A given a maximum of 100 burrows per acre (King 1959)..

No bait is to be left on the soil surface at the tim e of application. The applicator must retrieve and dispose of any bait that is spilled above gr ound or placed less than 6 inches down the burrow entrance. A second application may be made if BTPD activity persists se veral weeks or months after the initial bait application. Chlor ophacinone uncouples oxida tive phosphorylation depressing hepatic synthesis of prothrombin and clotting factors VII, IX, and X and it causes direct damage to capillary permeability. The ultimate effect is widespread internal hemorrhage. In rodents, this type of rodenticide also cau ses neurologic and cardiopu lmonary injuries which often lead to death before hemorrhage occurs.

1 Defenders of Wildlife v. U.S. EPA, Case No. 09-1199 (D.C. Cir., 2009); Defenders of Wildlife v. Jackson , Case No. 09-cv-1814 (D.D.C., 2009); NRDC v. U.S. EPA , Case No. 10-cv-1063, (D.D.C., 2010).



### 11

### EPA notes that several changes to the label of Rozol Prairi e Dog Bait (EPA reg. no. 7173-286) were approved on September 10, 2010. These change s consist of including: (1) a requirement

that carcass searches start within 4 days, rather than within 5 to 10 days of application; (2) a requirement that such searches continue at 1-2 day intervals, for two w eeks or potentially longer, as opposed to just a second repeat search at the 14-21 day interval; and (3) language that permits alternative carcass disposal to burial, where burial is impractical and the a lternative disposal will ensure no access by scavengers. While EPA expects these label changes will reduce the potential for exposure of non-targ et species to chlorophacinone this potential reduction does not quantitatively alter EPA's ecological risk assessment, nor does it alter EPA's effects

determinations relative to the use of Rozo l Prairie Dog Bait (EPA reg. no. 7173-286). Adherence to these label changes will reduce th e probability that contam inated prairie dogs or carcasses will be available to non-target species. However, these changes will not eliminate such availability nor will these change s eliminate the potential for non-ta rget species to be directly exposed to bait in the burrows or exposed to ba it that reaches the surface. While these label changes cannot preclude effects lik ely to adversely affect individua ls of a non-target species, the

reduction in the likelihood of such effects occu rring should be considered by the US Fish and Wildlife Service when considering whether the potential effects will or will not constitute jeopardy to any of the speci es potentially exposed.

1.2.2. Environmental Fate Properties of Chlorophacinone

Chlorophacinone is hardly mobile in soils and other organic matrices (K OC 

### = 15600-95745 mL/g) and nearly insoluble (34 mg/L). Chlorophaci none is formulated as a grain bait for this use and is expected to remain within the bait due to its immobility. Chlorophacinone would also be

immobile if it were to be soil incorporated. Based on its fate parameters measureable exposure to aquatic environments is not expected to o ccur. It is the opera ting assumption of this assessment that the fate of chlorophacinone in the environment from this use is entirely associated with the grain bait formulation.

1.2.3. Evaluation of Degradates and Stressors of Concern

Though degradates ( i.e. o-phthalic acid and p-chlorophenylphenyl acetic acid) have been detected in environmental fate studies, they will not be considered furthe r in this assessment. These environmental fate studies were performe d using the technical grade active ingredient (TGAI) rather than the bait formulation relevant to this assessment. Due to chlorophacinone’s immobility in soil, it is also reasonable to conc lude it is immobile within bait formulations. Chlorophacinone baits retain the parent com pound even after exposure to wet weather and moisture (Merson and Byers 1985). However, photodegradation occurs in a dry environment and the bait is in a dry environment. Degradates were not evaluated in carcass studies and based on this lack of data, it is assumed that the de gradates are equi-toxic to the parent compound.

Therefore this risk assessment will be conducted as if the parent is undegraded in the bait.

12

### 1.3. Assessment Procedures

1.3.1. Exposure Assessment

All listed species within the U.S. were considered in this assessment. Exposures that may occur are limited to exposure through consumption of chlorophacinone grain bait (primary exposure) or exposure through consumption of animal s/prey/carcasses that have consumed chlorophacinone grain bait (secondary exposure). Exposure can only occur if: 1) the species distribution overlaps or borders the distribution area of BTPD s where Rozol Prairie Dog Bait (EPA Reg. No. 7173-286) can be used; and 2) species occur in terrestrial habitats. Twenty one species meet these two criteria. Those species are: grizzly bear ( Ursus arctos horribilis ), American burying beetle ( Nicrophorus americanus ), Salt Creek tiger beetle ( Cicindela nevadica

lincolniana ), California condor ( Gymnogyps californianus ), whooping crane ( Grus americana ), Eskimo curlew ( Numenius borealis ), northern Aplomado falcon ( Falco femoralis septentrionalis ), black footed ferret ( Mustela nigripes ), Chiricahua leopard frog ( Rana

chiricahuensis ), jaguar ( Panthera onca ), Gulf Coast jaguarundi ( Herpailurus yagouaroundi

cacomitli ), Canada lynx ( Lynx Canadensis ), Preble’s meadow jumping mouse ( Zapus hudsonius preblei ), ocelot ( Leopardus pardalis ), Mexican spotted owl ( Strix occidentalis lucida ), piping plover ( Charadrius melodus ), New Mexican ridge-nosed rattlesnake ( Crotalus willardi

obscurus ), Sonora tiger salamander ( Ambystoma tigrinum stebbinsi ) black-capped vireo ( Vireo atricapilla ), golden-cheek warbler ( Dendroica chrysoparia ), and gray wolf ( Canis lupus ). Species overlap with BTPD range is demonstrated in Appendix A . Federally-designated critical

habitat 2 

### has been established for nine of these 21 species. Primary constituent elements 3 

### (PCEs) were used to evaluate whether chlorophacinone ha s the potential to modi fy designated critical

habitat.

1.3.1.a. Aquatic Exposure

Based on the physical/chemical pr operties of Rozol Prairie Dog Bait, chlorophacinone exposure to aquatic environments is not expected to occur. Previous assessments are consistent with this

conclusion and are further discussed and referenced in Section 2.4

.

2 

### ‘ Critical habitat’ is defined in the ESA as the geographi c area occupied by the species at the time of the listing where the physical and biological features necessary for the conservation of the sp ecies exist, and there is a need for special management to protect the listed species. It may also include areas outside the occupied area at the time of listing if such areas are ‘essential to the conservation of the species.’ Critical hab itat receives protection under Section 7 of the ESA through prohibition against destruction or adverse modification with regard to actions carried out, funded, or authorized by a federal Agency. Section 7 requires consultation on federal actions that are likely to result in the destruction or adverse modification of critical habitat. To be included in a critical habitat designation, the habitat must be ‘essential to the conservation of the species.’

3 Critical habitat designations identify, to the extent know n using the best scientific and commercial data available, habitat areas that provide essential lif e cycle needs of the species or areas that contain certain primary constituent elements (PCEs) (as defined in 50 CFR 414.12(b)). PCEs include, but are not limited to, space for individual and population growth and for normal behavior; food, water, air, light, minerals, or other nutritional or physiological requirements; cover or shelter; sites for breeding, reproduction, rearing (or development) of offspring; and habitats that are protected from disturbance or are representative of the historic geographical and ecological distributions of a species. Information specific to each species is provided in each ESA.



### 13

### 1.3.1.b. Terrestrial Exposure

Terrestrial exposure is assesse d based on two exposure routes: 1) exposure to chlorophacinone grain bait; and 2) exposure to animals/prey/carcasses poisoned by chlorophacinone grain bait. The active ingredient concentra tions for the two exposure routes are respectivel y determined from: 1) labeled active ingredient concentration of the grain bait; and 2) conservative residue concentrations from chlorophacinone poisoned ca rcass studies. For residue concentrations, exposure to BTPDs and non-target granivores ex posed to chlorophacinone bait are considered. The estimated environmental concentration (EEC) is derived by multiplying the active ingredient concentration in the food item by the food ingestion rate for a given species.

1.3.2. Toxic ity Assessment

Assessment endpoints are limited to di rect and indirect effects asso ciated with survival, growth, and reproduction. The effects determination asse ssment endpoints include direct toxic effects on survival, as well as indirect e ffects including reducti on of the prey base or modification of habitat. Mammalian toxicity data do not char acterize growth and repr oduction effects because mortality effects occur before thes e effects are seen in mammals. Data informing effects to avian reproduction are unavailable for this assessment. Th ese data were requested from the registrant but have not been received. As noted in the Overview Document (USEPA, 2004a), the Agency

relies on acute and chronic effect s endpoints that are e ither direct measures of impairment of survival, growth, or reproduction or endpoints for which there is a scientifically robust, peer reviewed relationship that can quantify the im pact of the measured effect endpoint on the assessment endpoints of survival, growth, and repr oduction. Data addressing chronic toxicity are currently not available for chlor ophacinone. For the purposes of th is assessment, risk cannot be precluded to any assessed bird, mammal or he rptile if exposure is expected to occur.

Direct effects to listed species were de termined by multiplying the active ingredient concentration in the food item by the ingestion rate for a given species to determine how much of the food item would have to be ingested to attain a toxic dose. There are no direct effects caused by toxicity to aquatic taxa because exposure does not occur. However, indirect effects based on loss of terrestrial prey items and habitat modi fication based on loss of rodent burrows were

assessed.

The Agency evaluated registrant-submitted studies and data from the open literature to characterize chlorophacinone toxicity. The most sensitive toxicity value available from acceptable or supplemental studies for each taxon re levant for estimating potential risks to the listed species and/or their designate d critical habitat was used to a ssess risk. The ecotoxicity data used in this assessment, including ECOTOX data and literature submitted to the public docket during the comment period for “Receipt of Petitio n Requesting EPA to Suspend the Registration of Rozol Prairie Dog Bait and Cancel Cert ain Application Sites” (EPA-HQ-OPP-2009-0684- 0001), are summarized in Section 2.8.1

. Literature submitted to the docket is cited in Appendix

D.

14

### 1.3.3. Measu res of Risk

Risk quotients (RQs) were compared to the Agency’s Levels of Concern (LOC) for terrestrial endangered species to identify in stances where chlorophacinone use to control BTPDs has the potential to adversely affect threatened and endangered species or modify their designated critical habitat, if the species has designated critic al habitat. When RQs for a particular type of effect are below the LOC, chlor ophacinone is considered to have “no effect” (NE) on the species or its designated critical habitat. Where RQ s exceed the LOC, a potential to cause adverse effects or habitat modification is identified, lead ing to a conclusion of “may affect” (MA). If chlorophacinone use to control BTPD s may affect the listed species, and/or may cause effects to designated critical habitat, the best available info rmation is considered to refine the potential for exposure and effects, and distinguish actions that are Not Likely to Adversely Affect (NLAA) from those that are Likely to Adversely Affect (LAA).

1.4. Summary of Conclusions

Geospatial analysis indicates that the chlor ophacinone action area which corresponds to BTPD range either overlaps or borders the range of all 21 threatened and endangered species that may be affected by this use. Based on the best available information, the Agency makes a MA determination for the use of chlorophacinone to control BTPDs for the following 21 species based on direct effects: grizzly bear, American burying beetle, Sa lt Creek tiger beetle, California condor, whooping crane, Eskimo curlew, north ern Aplomado falcon, black-footed ferret, Chirichaua leopard frog, jaguar, Gulf Coast ja guarundi, Canada lynx, Preble’s meadow jumping mouse, ocelot, Mexican spotte d owl, piping plover, New Mexi can ridge-nosed rattlesnake, Sonora tiger salamander, black- capped vireo, golden-c heeked warbler, and the gray wolf. Additionally, the Agency has determined that ther e is the potential for modification of designated

critical habitat from the use of the chemical. Pote ntial modification of critical habitat occurs for the following species: Salt Creek tiger beetle, whooping crane, Canada lynx, Preble’s meadow jumping mouse, Mexican spotted owl, pipi ng plover, and the New Mexican ridge-nosed

rattlesnake.

Based on the predicted environmental exposures, ch lorophacinone is likely to adversely affect

via direct effects the followi ng species: grizzly bear, American burying beetle, Salt Creek tiger beetle, California condor, whooping crane, Es kimo curlew, northern Aplomado falcon, blackfooted ferret, Chirichaua leopard frog, jaguar, Gulf Coast jaguarundi, Canada lynx, Preble’s meadow jumping mouse, ocelot, Mexican spotte d owl, piping plover, Sonora tiger salamander, black-capped vireo, golden-cheek ed warbler, and the gray wo lf. Based on the predicted environmental exposures to prey base species, ch lorophacinone is likely to adversely affect via indirect effects the following species: grizzly bear, American burying beetle, whooping crane, Eskimo curlew, northern Aplomado falcon, black-foot ed ferret, Chiricahua leopard frog, Preble’s meadow jumping mouse, New Mexican ridge-nosed rattlesnake, Sonora tiger salamander, and the gray wolf. The black footed ferret is likely to be adversely affected vi a indirect effects due to loss of potential burrow habitat. Preble’s m eadow jumping mice do not appear to use the burrows of other rodents therefore making it un likely that this species would be adversely affected by loss of burrow habitat. Chlorophacin one use to control BTPDs is expected to result in modification of the critical habitat PCEs for the following listed species: Salt Creek tiger

15

### beetle, California condor, whooping crane, Canada lynx, Preble’s meadow jumping mouse, Mexican spotted owl, piping plover, New Mexican ridge-nosed rattlesnake, and gray wolf. A summary of the risk conclusions and effects de terminations for the 21 listed species and the critical habitat for the Salt Creek tiger beetle , California condor, whooping crane, Canada lynx, Preble’s meadow jumping mouse, Mexican sp otted owl, piping plover, New Mexican ridgenosed rattlesnake, and the gray wolf is presented in Table 1.1 and Table 1.2 . Further information

on the results of the effects determination is included as part of th e Risk Description in Section

5.2

.

16

### Table 1.1 Effects Determination Summary for Effects of Chlorophacinone to 21 Endangered Species.

Basis for Determination Species Effects

Determination Direct Effects Indirect Effects

Grizzly bear LAA 1 Direct effects are expected for the grizzly bear based on the potential for this species

to consume the chlo rophacinone bait (RQ of 75.42 which exceeds the LOC of 0.1) or other prey items that may have consumed the chlorophacinone bait (RQ of 3.38 for exposure to BTPDs and RQ of 8.75 for exposure to non-target animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute

exposure. Indirect effects from the loss of the prey base are also expected because

effects to individuals within populations have been demonstrated in mammals ranging in size from 13 to 36,363 grams with RQ ranging

from 19 to 41. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

American burying beetle LAA Reproductive effects are expected for the American burying beetle. The American burying beetle uses mammalian and avian carcasses as a food resource during their reproduction cycle. Dosed carcasses negatively affected number of emerged beetles (MRID 47383001). Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Salt creek tiger

beetle LAA Reproductive effects are expected for the Salt Creek tiger beetle. Salt Creek tiger beetle larvae are potentially exposed to chlorophacinone residues through chlorophacinone exposed terrestrial

invertebrates. Dosed carcasses in a burying beetle study negatively affected number of emerged beetles (MRID 47383001). Similar a ffects are expected for the Salt Creek tiger beetle. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. This species uses mud banks of streams and seeps in

association with saline wetlands and exposed mud flats of saline wetlands which is distinct from the short grass prairie associated w ith BTPD habitat.

No indirect effects from habitat loss are expected because this species

does not use BTPD burrows.

California

condor LAA Direct effects to the California condor are expected through thei r potential exposure to prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. No indirect effect s from the loss of prey base are expected because this species’ range does not overlap with the BTPD range. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Whooping crane LAA Direct effects to the whooping crane are expected to occur based on the potential for this species to consume the chlorophacinone bait (RQ of 0.89 which exceeds the LOC of 0.1) or other prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected



### 17exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. because this species does not use

BTPD burrows.

Eskimo curlew LAA Direct effects to the Eskimo curlew are expected to occur based on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of

chronic data. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated

in terrestrial invertebrates. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Northern Aplomado

falcon LAA Direct effects to the northern Aplomado falcon are expected through their potential exposure to prey items that may have

consumed the chlo rophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Black-footed

ferret LAA Direct effects are expected for the blackfooted ferret based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 7.45 for exposure to BTPDs and RQ of 19.29 for exposure to non-target animals, both which exceed the LOC of 0.1). Significant exposure is expected to occur because black-footed ferrets prey primarily on BTPDs. Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute

exposure. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial invertebrates. In addition, this species preys almost exclusively on

BTPDs. Indirect effects from habitat loss are expected because this species

uses BTPD burrows.

Chirichaua leopard frog LAA Direct effects to the Chirichaua leopard frog are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated

in terrestrial invertebrates and birds.

No indirect effects from habitat loss are expected because this species does not appear to use BTPD

burrows.

Jaguar LAA Direct effects are expected for the jaguar based on the potential for this species to consume prey items that may have

consumed the chlo rophacinone bait (RQ of 12.69 for exposure to BTPDs and RQ of 32.85 for exposure to non-target No indirect effect s from the loss of the prey base are expected because this species’ habitat is distinct from the BTPD habitat. Jaguars – particularly males of the northern reaches – are known to have large



### 18animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. home ranges that encompass a variety of plant communities,including: Maderan evergreenwoodland, subalpine conifer forest, semidesert shrubland, and Sonoran desert scrub. Washes and riparian areas with dense vegetative growth may also be valuable movement

corridors. These habitats are distinct from the short grass prairie

associated with BTPD habitat. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Gulf Coast jaguarundi LAA Direct effects are expected for the Gulf Coast jaguarundi based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 9.20 for exposure to BTPDsand RQ of 23.82 for exposure to nontarget animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. No indirect effect s from the loss of the prey base are expected because this species’ habitat is distinct from the BTPD habitat. This species is found in chaparral plant communities and dense brushy areas near streams

and rivers which are distinct from the short grass prairie associated with

BTPD habitat. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Canada lynx LAA Direct effects to the Canada lynx are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinonebait (RQ of 23.30 for exposure to nontarget animals and RQ of 9.00 for exposure to BTPDs both of which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. The Canada lynx is associated with the southern,

transitional reaches of the cool and

moist boreal forest. Where it occurs at these lower latitudes, the boreal

forest forms a mixed conifer and conifer-hardwood landscape. These

habitat areas are distinct from the short grass prairie associated with

BTPD habitat. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Preble’s

meadow jumping mouse LAA Direct effects to the Preble’s meadow jumping mouse are expected to occur based on the potential for this species to consume the chlorophacinone bait (RQ of 41.35 which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute

exposure. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in terrestrial invertebrates. Although this species makes nests both above and below ground. It does not appear to use other species’ burrows.

Ocelot LAA Direct effects are expected for the ocelot based on the potential for this species to No indirect effects from loss of prey base are expected because this



### 19consume prey items that have may

consumed the chlo rophacinone bait (RQ of 10.41 for exposure to BTPDs and RQ of 26.96 for exposure to non-target animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. species’ habitat is distinct from BTPD habitat. Ocelots appear to use areas of dense cover, and in the northern part of the range hunt in brushy forests and semi-arid deserts. In the southern part of its range, ocelot habitat includes tropical forests, mountain slopes, and pampas (grasslands). These habitat areas are distinct from the short grass prairie

associated with BTPD habitat. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Mexican spotted

owl LAA Direct effects to the Mexican spotted owl are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. Mexican spotted owls are found in old-growth or mature forests with unevenly aged stands of trees, high canopy, multi-storied levels, and high tree density as well as canyons with riparian or conifer

communities. In Arizona and New Mexico they are found in habitatsassociated with mixed conifer, pineoak, Arizona cypress, oak woodlands, and associated riparian

forests. These habitat areas are distinct from the short grass prairie

associated with BTPD habitat. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Piping plover LAA Direct effects to the piping plover are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinonebait (RQ of 0.104 for exposure to nontarget animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. The plover’s home range within BTPD range is usually limited to the wetland, lakeshore, or

section of beach where its nest is

located. No indirect effects from habitat loss are expected because this species does not use BTPD burrows.

New Mexican ridge-nosed

rattlesnake LAA No direct effects based on survival to the New Mexican ridge-nosed rattlesnake are expected to occur (see Section 5.1.1.a. RQs of 0.018 for a 50 gram snake and RQ of 0.030 for a 500 gram snake. Neither of these RQs exceeds the LOC of 0.1). However, growth and reproductive effects cannot be precluded due to the absence of

chronic data. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not appear

use BTPD burrows.

Sonora tiger

salamander LAA Direct effects to the Sonora tiger salamander are expected to occur based on the potential for this species to consume No indirect effect s from the loss of prey base or loss of habitat (BTPD burrow) are expected because this



### 20prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. species’ range does not overlap with BTPD range.

Black-capped

vireo LAA Direct effects to the black-capped vireo are expected to occur based on the potential for this species to consume prey

items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. Black-capped vireos

are found in mixed deciduous/evergreen shrub land. Breeding vireos use shrubby growth of irregular height and distribution with spaces the small thickets and clumps and with vegetative extending to ground level. These

habitat areas are distinct from the short grass prairie associated with

BTPD habitat. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Golden-cheeked

warbler LAA Direct effects to the golden-cheeked warbler are expected to occur based on the potential for this species to consume prey

items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from

BTPD habitat. Golden-cheeked

warblers are found in mixed Ashejuniper and oak woodlands in ravines and canyons. They spend summers in open canopy forest and winters in closed canopy forests. These habitat areas are distinct from the short grass prairie associated w ith BTPD habitat.

No indirect effects from habitat loss are expected because this species

does not use BTPD burrows.

Gray wolf LAA Direct effects to the gray wolf are expected to occur based on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 24.82 for exposure to non-target animals and RQ of 9.59 for exposure to

BTPDs both of which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

1 LAA=likely to adversely affect.



### 21

### Table 1.2. Effects Determination Summary for the Critical Habitat Impact Analysis
Species with Designated Critical

Habitat Effects

Determination Basis for Determination

Salt Creek tiger beetle HM 1 Reproductive effects are expected for the Sa lt Creek tiger beetle. Salt Creek tiger beetle larvae are potentially expose d to chlorophacinone residues through chlorophacinone exposed terrestrial inverteb rates. Dosed carcasses in a burying beetle study negatively affected number of emerged beetles (MRID 47383001). Similar affects are expected for the Salt Cr eek tiger beetle. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. This species uses mud banks of streams and seeps in association with saline wetlands and exposed mud flats of saline wetlands which is distinct from the short grass prairie associated w ith BTPD habitat. No indirect effects from habitat loss are expected because th is species does not use BTPD burrows.

California condor No habitat

modification

expected Direct effects to the California condor are expected thro ugh their potential exposure to prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1. No

indirect effects from the lo ss of prey base are expected because this species’ range does not overlap with BTPD range. No indirect effects from habitat loss are expected because this species does not use BTPD burrows. No habitat modification is expected because the critical habitat for the California condor does not overlap with the use area (BTPD hab itat). Critical habitat for the California condor has only been designated in California.

Whooping crane HM Direct effects to the whooping crane are expected to occur based on the potential for this species to consume the chloro phacinone bait (RQ of 0.89 which exceeds the LOC of 0.1) or other prey items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals whic h exceeds the LOC of 0.1).

Indirect effects from the loss of the prey base are also expected because effects to individuals within populations have been demonstrated in mammals, birds, and

terrestrial invertebrates. No indirect effects from habita t loss are expected because this species does not use BTPD burrows. Habitat modification for the whooping crane is expected because the critical habitat for the whoo ping crane overlaps with the use area (BTPD habitat).

Canada lynx HM Direct effects to the Canada lynx are exp ected to occur based on the potential for this species to consume prey items that have consumed th e chlorophacinone bait (RQ of 23.30 for exposure to non-target animals and RQ of 9.00 for exposure to

BTPDs both of which exceed the LOC of 0. 1). No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. The Canada lynx is associated with the southern, transitional reaches of the cool and moist boreal forest. Where it occurs at these lower latitudes, the boreal forest

forms a mixed conifer and conifer-hardwood landscape. These habitat areas are distinct from the short grass prairie associ ated with BTPD habitat. No indirect effects from habitat loss are expected b ecause this species does not use BTPD burrows. Habitat modification for the Canada lynx is expected because the critical habitat for the Canada lynx overlaps with the use area (BTPD habitat).

Preble’s meadow jumping mouse HM Direct effects to the Preble’s meadow ju mping mouse are expected to occur based on the potential for this species to consume the chlorophacinone bait (RQ of 41.35 which exceeds the LOC of 0.1). Indirect ef fects from the loss of the prey base are expected because effects to individuals within populations have been demonstrated in terrestrial invertebrates. Although this species makes nests both above and below ground, it does not appear to use other species’ rodent burrows. Habitat modification for the Preble’s meadow ju mping mouse is expected because the

critical habitat for the Preble’s meadow jumping mouse overlaps with the use area (BTPD habitat).



### 22Mexican spotted owl HM Direct effects to the Mexican spotted ow l are expected to occur based on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 0.104 for ex posure to non-target animals which exceeds the LOC of 0.1). No indirect effe cts from loss of prey base are expected because this species’ habitat is distinct fr om BTPD habitat. Mexican spotted owls are found in old-growth or mature forests with unevenly aged stands of trees, high canopy, multi-storied levels, and high tree density as well as canyons with riparian

or conifer communities. In Arizona and New Mexico they are found in habitats associated with mixed conifer, pine-oak, Arizona cypress, oak woodlands, and associated riparian forests. These habita t areas are distinct from the short grass prairie associated with BTPD habitat. No indirect effects from habitat loss are expected because this species does not us e BTPD burrows. Habitat modification for the Mexican spotted owl is expected because the critical habitat for the Mexican spotted owl overlaps with the use area (BTPD habitat).

Piping plover HM Direct effects to the piping plover are expected to occur based on the potential for this species to consume prey items that have consumed th e chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). No indirect effects from the loss of the invertebrate prey base are ex pected because this species’ habitat is distinct from BTPD habitat. The plover’s home range within the BTPD range is usually limited to the wetland, lakeshore, or section of beach where its nest is

located. No indirect effects from habita t loss are expected because this species does not use BTPD burrows. Habitat modification for the piping plover is expected because the critical habitat for the piping plover overlaps with the use area (BTPD habitat).

New Mexican ridgenosed rattlesnake HM No direct effects based on survival to the New Mexican ridge-nosed rattlesnake are expected to occur (see Section 5.1.1.a. RQs of 0.018 for a 50 gram snake and RQ of 0.030 for a 500 gram snake. Neither of these RQs exceeds the LOC of 0.1). However, direct effects based on reproduction cannot be precluded because no reproduction data are available. Indirect effects from the loss of the prey base are expected because effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial invertebra tes. No indirect effects from habitat loss are expected because th is species does not appear to use BTPD burrows.

Habitat modification for the New Mexican ridge-nosed rattlesnake is expected

because the critical habitat for the New Mexican ridge-nosed rattlesnake overlaps with the use area (BTPD habitat).

Gray wolf No habitat

modification

expected Direct effects to the gray wo lf are expected to occur base d on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 24.82 for exposure to non-target animals and RQ of 9.59 for exposure to BTPDs both of which exceed the LOC of 0.1). In direct effects from the loss of the prey base are also expected because effects to individuals within populations have been demonstrated in mammals, birds, and terrestri al invertebrates. No indirect effects from habitat loss are expected because th is species does not use BTPD burrows. No habitat modification is expected because the critical habitat for the gray wolf does not overlap with the use area (BTPD ha bitat). Critical habitat for the gray wolf has only been designated in Minnesota and Michigan.

1 Habitat Modification The assessment endpoint for each species above is the modification of PCEs.



### Based on the conclusions of this assessment, formal consultation with the U. S. Fish and Wildlife

Service under Section 7 of the Endangered Species Act should be initiated relative to potential effect on the 21 species noted a bove in Table 1.1, and on the pot ential for critical habitat modification for the 7 species noted above in Table 1.2

23

### When evaluating the significance of this risk assessment’s direct/indire ct and adverse habitat modification effects determinations, it is impor tant to note that rodenticide exposures and predicted risks to the species and its resources ( i.e ., food and habitat) are not expected to be

uniform across the action area since BTPDs are not uniformly distributed across action area. Evaluation of the implication of this non-uniform distribution of risk to the species would require information and assessment techniques that are not currently available. Examples of such information and methodology required for this ty pe of analysis would include the following:

• Enhanced information on the density and distribution of BTPD s within the action area and information on the density and dist ribution of the other 21 listed species

within the action area and information on th e density and distribution within their critical habitat of the nine species with critical habitat. This information would allow for quantitative extrapolation of the present risk assessment’s predictions of

individual effects to the proportion of the population extant within geographical areas where those effects are predic ted. Furthermore, such population information would allow for a more compre hensive evaluation of the significance of potential resource impairment to individuals of the listed species.

• Quantitative information on prey base require ments for the listed species. While existing information provides a preliminar y picture of the types of food sources utilized by the listed species, it does not establish minimal requirements to sustain healthy individuals at varyi ng life stages. Such information could be used to establish biologically rele vant thresholds of effects on the prey base, and ultimately establish geographical limits to those effects. This information could be used together with the density da ta discussed above to characterize the

likelihood of adverse effects to individuals.

• Information on population responses of prey base organisms to chlorophacinone. Currently, methodologies are limited to pr edicting exposures and likely levels of direct mortality, growth or reproduct ive impairment immediately following exposure to chlorophacinone. The degree to which repeated exposure events and the inherent demographic characteristic s of the prey population play into the extent to which prey resources may rec over is not predictable. An enhanced understanding of long-term prey respons es to chlorophacinone exposure would

allow for a more refined determination of the magnitude and duration of resource impairment, and together with the information described above, a more complete prediction of effects to i ndividual species a nd potential modification to critical

habitat.

• Furthermore, additional information is need ed on the types of plants in the BTPD range to fully characterize/assess the direct effects on plants that are found within

the action area as well as to determine the indirect effects on the threatened and endangered animal species which are asse ssed in this document. Although, it is known that the BTPD is a keystone speci es, it is currently unclear what impacts

the loss of the BTPD would have both on plant communities within the action

area as well as what effects this woul d have on listed species. Additional information on species occurrence, distribution, life history and species

associations would be bene ficial to determine potentia l effects to listed plant species.

24

### 2. Problem Formulation

Problem formulation provides a strategic framewor k for the risk assessment. By identifying the important components of the proble m, it focuses the assessment on the most relevant life history stages, habitat components, chemical properties, exposure routes, and en dpoints. The structure

of this risk assessment is based on guidance contained in U.S. EPA’s Guidance for Ecological

Risk Assessment (USEPA, 1998), the Services’ Endangered Species Consultation Handbook (USFWS/NMFS, 1998) and is consistent with procedures and methodology outlined in the Overview Document (USEPA, 2004a) and reviewed by the U.S. Fish and Wildlife Service and

National Marine Fisheries Se rvice (USFWS/NMFS/NOAA, 2004).

2.1. Purpose

The purpose of this endangered species assessment is to evaluate potential direct and indirect effects on all listed species arising from FI FRA regulatory actions regarding use of chlorophacinone to control BTPDs. In addition, this assessment ev aluates whether use to control BTPDs is expected to result in modification of th e listed species’ designated critical habitat, for those species with designated critical habitat.

In this assessment, direct and indirect effects to listed specie s and potential modification to designated critical habitat for listed species is evaluated in accordance with the methods described in the Agency’s Overview Document (USEPA, 2004a). In accordance with the Overview Document, provisions of the Endange red Species Act (ESA), and the Services’ Endangered Species Consultation Handbook, the assessment of effects associated with registration of chlorophacinone for BTPDs is based on an action area. The action area is the area directly or indirectly affect ed by the federal action. The ac tion area for a FIFRA regulatory decision associated with a use of chlorophacinon e to control BTPDs involves 532 counties in 10 states (Colorado, Kansas, Montana, Nebraska , New Mexico, North Dakota, Oklahoma, South Dakota, Texas and Wyoming) based on the range of the BTPD and data regarding listed species

obtained from NatureServe 4 

### . However, for the purposes of th is assessment, attention will be

focused on relevant sections of the action area including those geographic areas associated with locations of listed species that may be affected and their designated critical habitat. As part of the “effects determination,” one of the following th ree conclusions will be reached separately for each of the assessed species regarding the potenti al use of chlorophacinone in accordance with

the assessed label:

• “No effect” or “NE”;

• “May affect, but not likely to adversely affect” or “NLAA”; or

• “May affect and likely to adversely affect” or “LAA”.

A risk quotient (RQ) is the ratio of the esti mated environmental concentration (EEC) to the relevant toxicological endpoint, often the LD 50 

### or LC 50 

### . RQs were compared to the Agency’s LOC for terrestrial endangered species to id entify instances where chlorophacinone use to

4 NatureServe: NatureServe Explorer [web application]. Updated February 2010. Arlington, Virginia (USA):
Available: http://www.natureserve.org/ explorer. (Accessed: May 12, 2010 )



### 25

### control BTPDs has the potential to adversely affect the assess ed species or modify their designated critical habitat. When RQs fo r an effect endpoint are below the LOC, chlorophacinone is considered to ha ve NE on the species or its desi gnated critical habitat. Where RQs exceed the LOC, a potential to cause advers e effects or habitat m odification is identified, leading to a conclusion of May Affect. If chlorophacinone use may affect the assessed species, and/or may cause effects to designated critical habitat, the best available information is considered to refine the potential for exposure an d effects, and distinguish actions that are NLAA

from those that are LAA. The best available information relative to this assessment includes species life history information which is compiled in Attachment 1

.

2.2. Scope

The end result of the EPA pesticide registration process ( i.e. , the FIFRA regulatory action) is an approved product label. The label is a legal document that stipulates how and where a given pesticide may be used. Product labels (also know n as end-use labels) de scribe the formulation type ( e.g. , liquid or granular), acceptable methods of application, approved use sites, and any restrictions on how applications may be c onducted. Thus, the use of chlorophacinone in accordance with the approved product label for BTPDs is “the action” relevant to this ecological

risk assessment.

Chlorophacinone end-use products in clude tracking powder, bait bloc ks, pelleted baits, and grain baits. The use of chlorophacinone for contro l of BTPDs only permits use of grain bait formulated with 50 mg a.i./kg-bait active ingred ient. This bait is permissible for use only

between October 1 and March 15 or spring green-up, whichever occu rs later, in active prairie dog burrows. The bait must be placed at least 6 inches into the bu rrow and below the ground

surface. Two carcass searches ar e to occur after app lication, the first being 5 to 10 days postapplication and the second being 14-21 days post-application. Primary and secondary exposure to non-target animals is possible based on this use pattern. Primary exposure takes place when the grain bait is consumed by non-target species. This type of exposure can occur on the surface, as a result of bioturbation, or while the bait is in the burrow. Secondary exposure takes place when chlorophacinone poisoned/contaminated BTPD s or non-target animal s or carcasses, are consumed by non-target species. Dead and dying animals may be exposed on the surface or may be found by predators or scavengers in burrows.

EPA notes that several changes to the label of Rozol Prairi e Dog Bait (EPA reg. no. 7173-286) were approved on September 10, 2010. These change s consist of including: (1) a requirement

that carcass searches start within 4 days, rather than within 5 to 10 days of application; (2) a requirement that such searches continue at 1-2 day intervals, for two w eeks or potentially longer, as opposed to just a second repeat search at the 14-21 day interval; and (3) language that permits alternative carcass disposal to burial, where burial is impractical and the a lternative disposal will ensure no access by scavengers. While EPA expects these label changes will reduce the potential for exposure of non-targ et species to chlorophacinone this potential reduction does not quantitatively alter EPA's ecological risk assessment, nor does it alter EPA's effects

determinations relative to the use of Rozo l Prairie Dog Bait (EPA reg. no. 7173-286). Adherence to these label changes will reduce th e probability that contam inated prairie dogs or carcasses will be available to non-target species. However, these changes will not eliminate such

26

### availability nor will these change s eliminate the potential for non-ta rget species to be directly exposed to bait in the burrows or exposed to ba it that reaches the surface. While these label changes cannot preclude effects lik ely to adversely affect individua ls of a non-target species, the

reduction in the likelihood of such effects occu rring should be considered by the US Fish and Wildlife Service when considering whether the potential effects will or will not constitute jeopardy to any of the speci es potentially exposed.

Although current registrations of the active ingredient chlorophaci none allow for use nationwide, this ecological risk assessment and effects determ ination addresses only the registered use of the Rozol Prairie Dog Bait ((EPA registration number 7173- 286) which is registered only to control BTPD on rangeland and noncrop areas in Colora do, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas and Wyoming. Listed species considered in this

assessment will occur within and adjacent to counties where BTPD s are known to occur and will be reasonably assumed to have potential for ch lorophacinone exposure. Further discussion of the action area, the listed species and their de signated critical hab itat is provided in Section 2.7

.

2.2.1. Evaluation of Degradates

Though degradates ( i.e. o-phthalic acid and p-chlorophenylphenyl acetic acid) have been detected in environmental fate studies, these de gradates will not be cons idered further in this

assessment. These environmental fate studies we re performed using TGAI rather than the bait

formulation relevant to this assessment. Due to chlorophacinone’s immo bility in soil, it is

reasonable to conclude it is immobile within ba it formulations. Chlorophacinone baits typically retain the parent compound even after exposure to wet weather and moisture (Merson and Byers 1985). However, photodegradation occurs in a dry environment and the bait is in a dry environment. Degradates were not evaluated in carcass studies and based on this lack of data, it is assumed that the degradates are equi-toxic to the parent compound. Therefore this risk

assessment will be conducted as if th e parent is undegraded on the bait.

2.2.2. Evaluation of Mixtures

Product toxicity data for Rozol (2% a.i.) indicates that the formulated pro duct is not more toxic than the TGAI compared on a w/w active ingr edient basis (MRID 43672005) . Rozol Prairie Dog Bait is 50 mg a.i./kg-bait but the approximate amount of inert material is equivalent and composed of the same materials with the excep tion of the grain base. The formulation of chlorophacinone evaluated in this risk assessment does not contain any other active ingredients.

2.3. Previous Assessments

“Potential Risks of Nine Rodenticides to Birds and Nontarget Mammals: a Comparative Approach” (USEPA 2004b) evaluated primary and secondary exposure of chlorophacinone, among other rodenticides, to birds and mammals. This study determined that the greatest risk of chlorophacinone use to non-target anim als is via secondary exposure to mammals. Risk associated with primary exposure and exposure to birds, however, is also significant. These elements provide the general framewo rk for this assessment and are supported through the calculation of RQs in this assessment. The st udy also specified a number of

27

### factors contributing to uncertainty in assessi ng anticoagulant rodentic ides. Those factors that contributed the most uncertainty were: (1) missing data, including acute, chronic, and secondary toxicity as well as data regarding retention of some active ingredients in the liver, blood, and other body tissues; (2) th e variable quality and quan tity of existing data on

metabolism and retention times in rodents and nontarget species; (3) specific use information by formulation, including typical amounts applied by use site, seasonally, and annually; distances applied from buildings; amo unts used in rural versus urban areas; use by Certified Applicators versus homeowners and ot her non-certified applicators; and other such relevant information; (4) information on th e number and species of birds and nontarget mammals frequenting baited areas and the like lihood of their finding and consuming bait or poisoned primary consumers in the various use areas; (5) methods to determine liver concentration(s) and total body bur dens of rodenticide that woul d corroborate death or even if such a cause-effect relationship is a ppropriate (e.g., the “threshold of toxicity” concentration); (6) not accoun ting for the impacts of sublet hal effects on reproduction and nontarget mortality (e.g., clotting abnormalities, hemorrhaging, stress factors including environmental stressors, such as adverse weather conditions, f ood shortages, and predation); (7) not accounting for bioaccumulation of repeat ed sublethal exposures to bait or poisoned rodents utilized as food by predators and scavenge rs; and (8) lack of in cident reporting. All

of the above issues remain as unc ertainties for this assessment.

In November 2008, an Ecological Risk A ssessment evaluating expanded uses of chlorophacinone for BTPDs was performed. The assessment offered the following recommendations for risk mitigation: (1) requiring carcass searches at 1-to-2 day intervals; (2) requiring non-target animal carcasses be provide d to proper authorities for identification and tissue-residue analysis; (3) requiri ng a discrete application interv al so that full monitoring and

carcass removal from the initial a pplication may be completed; a nd (4) taking into consideration the black-footed ferret because it is an endange red species, preys on the target species as a primary food source and utilizes their burro ws. The resulting product label reflected recommendations from the assessment in the following ways: (1) requiring an initial carcass search 5 to 10 days after application and a second carcass search 14 to 21 days after application; (2) allowing reapplication “several weeks” after initial application; and (3) stating: “[d]o not use this product within prairie dog towns in the range of the black-footed ferret without first contacting endangered species specialists at a U.S. Fish and Wildlife Service office.”

2.4. Environmental Fate Properties

Chlorophacinone is hardly mobile with half-l ives ranging from 37 minutes (Direct Aqueous Photolysis) to 45 days (Aerobic Soil Metabolism, sandy clay loam) and the major environmental dissipation processes are photolys is and metabolism. These pr operties of chlorophacinone are

summarized in Table 2.1 . Chlorophacinone and its degradates are not likely to dissipate from the grain bait formulation due to the chemi cal’s immobility. Chlorophacinone residues can be expected to occur in chlorophacinone exposed animal carcasses (Belleville 1981; Dowding 2010; MRID 47333603). Further discussi on of the implications of chlorophacinone residues in

carcasses will be limited to Section 2.4.1 . For the purposes of discus sion of environmental fate, discussion will be limited to exposure to th e chlorophacinone grain bait formulation only.

28

### Table 2.1 Physical-chemical Properties of chlorophacinone

Study Value and units Major Degradates Minor Degradates MRID # Study

Status

Structure

Hydrolysis Stable at pH 5, 7, 9 42205501 Acceptable Solubility 34 mg/L @ 25oC EPA 1998 (Rodenticide Cluster RED) Direct Aqueous Photolysis T 1/2 = 90 minutes 42205502 Acceptable

Soil Photolysis T 1/2 = 4 days o-phthalic acid; p-chlorophenylphenyl

acetic acid 42452301 Acceptable

Aerobic Soil

Metabolism T 1/2 = 45 days; sandy clay loam

T 1/2 = 26 days; sandy loam o-phthalic acid; p-chlorophenylphenyl

acetic acid 43159801 Acceptable

Anaerobic Soil

Metabolism No Data

Aerobic Aquatic

Metabolism No Data

Anaerobic Aquatic

Metabolism No Data

Soil Water Partition

Coefficient K fads 56 to 1000 mL/g

K OC 15600, 26900, 35400, 95745 mL/g (the Koc model appears valid) 42666001 Acceptable

Terrestrial Field Dissipation No Data



### 2.4.1. Environmental Transport Mechanisms

Given chlorophacinone’s physical/chemical pr operties, grain bait formulation and low application rate, it is assumed that negligible amounts of pare nt chlorophacinone and degradate leach from the original bait. Toxicological data on chlorophacinone degradates are not available

and are therefore assumed to be as toxic as the parent, chloroph acinone. Given this, the exposure concentration of 50 mg a.i./kg-bait is assume d to remain constant overtime within the formulation. Chlorophacinone has the potential to be available in significant concentrations via carcass residues. Ecological in cident data, carcass residue da ta and poisoned carcass feeding

studies indicate that chlorophacinone poisoned ca rcasses have the potentia l to adversely affect

29

### scavengers and predators. Chlorophacinone degr adates have not been evaluated in carcass

studies.

2.4.2. Mechanism of Action

Chlorophacinone is an indandi one anticoagulant rodenticid e. It uncouples oxidative phosphorylation depressing hepatic s ynthesis of prothrombin and cl otting factors VII, IX and X and, it causes direct damage to capillary permeabili ty. The ultimate effect is widespread internal hemorrhage. In rodents, indandiones also cause neurologic and cardiopulm onary injuries which often lead to death before hemorrhage occurs (World Heal th Organization, 2010).

2.4.3. Use Characterization

The chlorophacinone product assessed here is regi stered only as a 50 mg a.i./kg-bait grain bait formulation for control of BTPDs. For each active burrow during a single application, 53 grams of bait are to be applied no less th an 6 inches down the burrow. If prairie dog activity persists, a second application at the same use rate can be ma de “several weeks later” . Neither the National Agricultural Statistics Service (NASS) nor the United States Geological Su rvey (USGS) is able to provide geographical data fo r chloropacinone use to control BTPDs but species distribution data, provided by NatureServe at the county level, provides a conservative proxy for the area in which chlorophacinone may be used for this pur pose. This use area is illustrated in Figure 2.1

. This species distribution area conservatively repr esents the use area because it represents the historic range for the BTPD. Current and future ra nge relative to historic range is likely to be

smaller and discontinuous but still within the b oundaries of this historic range.

30

### Figure 2.1. Chlorophacinone use area for BTPDs

31

### 32 2.5. Assessed Species

This assessment considers all listed species wi thin the U.S. However, the 10 states where chlorophacinone use to control BTPDs is permissible (Colora do, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakot a, Texas, and Wyoming) and the adjacent counties ( i.e., the action area) are the only areas where exposure is expected to occur. One hundred forty two (85 animals and 57 plants) threatened and endangered species are listed within the action area according to the USFWS Web site 5 

### . Based on species diet, terrestrial habitat and the distribution of BTPDs, chlo rophacinone will have NE on 87 of the 142 species. The list of species for further assessment then is limited to 21 animals (grizzly bear, American burying beetle, Salt Creek tiger beetle, California c ondor, whooping crane, Eskimo curlew, northern Aplomado falcon, black footed ferret, Chiricahua leopard frog, jaguar, Gulf Coast jaguarundi, Canada lynx, Preble’s meadow jumping mouse, ocelot, Mexican spotted owl, piping plover, New Mexican ridge-nosed rattlesnake, Sonora tiger salamander, black-capped vireo, golden-cheek warbler, and the gray wolf). A list of the 34 plant species is included in Section 2.5.1 but not carried through the assessment because it is unclear what impacts th e loss of the BTPD may have on these plants.

For the animal species ingestion is the only si gnificant route of expos ure and the only exposure

route assessed in this document and for that, the species’ diet must be that of a granivore or it must be attracted to grain baits to have primary exposure to chlorophacinone; it must be a carnivore or scavenger to have secondary exposure to chlorophac inone. It was also determined that insects may be exposed to the grain bait and may retain residues that are high enough to cause direct mortality to inverti vores. As a result, direct effect s to invertivores will also be assessed. Based on the potential for exposure, the list of species for furt her assessment is limited to the 21 terrestrial species noted in Table 1.1

. Table 2.2 provides a summary of the current distribution, habitat requirements, a nd relevant life history parameters for these 21 species. More detailed life-history and distri bution information can be found in Attachment 1 . Maps indicating listed species locat ion relative to historic rang e of BTPDs can be found in Appendix

A

.

5 http://www.fws.gov/endangered/Table 2.2 Summary of Current Distribution, Habitat Requirements,and Life History Informationfor Listed Species that Maybe Affected.SizeCurrent RangeHabitat TypeReproductiveCycleDietGrizzly bear(Ursus arctos horribilis) – critical habitat has been proposedAverage weightfor males: 181-272 kg (400-600 lbs)Sections of Washington,Wyoming, Idaho, andMontana.Spring: Low elevation riparian sites,wet meadows, and alluvial plains.Mating between May and July.Implantation of blastocyst(s) delayeduntil hibernation (4-5 months later).Freshly emergentherbaceous vegetation ispreferred.Average weightfor females:113-158 kg(250-350 lbs)Summer and fall: Higher elevationforests, meadows, and open grassytimber sites.Hibernate between October andDecember. Exits the den betweenMarch and May. Implantation of theembryo is delayed and gestationusually lasts about 26 weeks.Grasses, sedges, roots,tubers, and berries composea large part of the diet.Yellowstoneadults: 102-324kg (225-714lbs)Meadows, shrubfields, and low- andhigh-elevation riparian communitiesare also important habitat.Ungulates, ground squirrels,carrion, and garbage.Length (snout totail): 170-280cm (5.5-9.1 ft)Alsopreyonmice,groundsquirrels, and marmots.Shoulder height:90-150 cm (3.1-4.8 ft)Grizzly bears have beenidentified in six areas inthe Rocky Mountains:1) the GreaterYellowstone Ecosystem(GYE); 2) the NorthernContinental DivideEcosystem (NCDE); 3)the BitterrootEcosystem (BE); 4) theCabinet-YaakEcosystem (CYE); 5)the Selkirks Ecosystem(SE); and 6) theNorthern CascadesEcosystem (NCE)33SizeCurrent RangeReproductiveHabitat TypeDietCycleAmerican burying beetle(Nicrophorus americanus) – no designated critical habitat2.5-3.5 cm (1.0-1.4 inches) inlengthOccurs in the followingstates: Arkansas,Kansas, Massachusetts(statewide), Michigan(statewide), Missouri,Nebraska, Ohio,Oklahoma, RhodeIsland (statewide),South Dakota, andTexas.Eastern deciduous biome. Ripariandeciduous forests, grasslands,pastures, and maritime scrub thickets.Active from April through Septemberbut seen as early as February and aslate as October. Breeding in the east(Block Island) occurs between Juneand July. Breeding in the west(Oklahoma) occurs between late Apriland mid-August.Broad range of availablecarrion and possibly liveinsects. Uses large (100-200 g) (0.2-0.4 lbs)mammal or bird carcassesfor brood-rearing. Can usecarcasses as small as 35 g(0.08 lbs). Prefer ring-neckpheasant and Americanwoodcock carcasses.Salt Creek tiger beetle(Cicindela nevadica lincolniana) – designated critical habitat1.3 cm (0.5inches) totallengthConfined to easternNebraska salinewetlands and associatedstreams and tributariesof Salt Creek in thenorthern third ofLancaster County.Mud banks of streams and seeps, andin association with saline wetlandsand exposed mud flats of salinewetlands. Larvae have been foundonly on moist salt flats and saltencrusted banks of Little Salt Creekin northern Lancaster County andsaline wetlands associated with RockCreek in the southern margin ofSaunders County. Salt Creek tigerbeetles require open, barren salt flatareas for construction of larvalburrows, thermoregulation, foraging,and as dispersal corridors.Adults are first observed as early asthe end of May or as late as mid-June.Their numbers peak about two weeksafter the first individuals appear andbegin to feed and mate. Females laytheir eggs along sloping banks ofcreeks in areas where the salt layer isexposed in the soil horizon, on barrensalt flats of saline wetlands, or alongsaline stream edges that are found inclose association with water, near aseep or stream. It is believed that,during the night, female Salt Creektiger beetles lay about 50 eggs. TheSalt Creek tiger beetle has a two-yearlife cycle.Smaller or similar-sizedarthropods.34SizeCurrent RangeReproductiveHabitat TypeDietCycleCalifornia condor(Gymnogyps californianus) – designated critical habitatAdults weigh upto 10 kg (22 lbs)Average maleweight: 8.8 kg(19.4 lbs)Average femaleweight: 8.1 kg(17.9 lbs)In Arizona, the condoris known to exist inApache, Coconino,Mohave, Navajo, andYavapai counties. Thisspecies is also found inseveral counties inCalifornia.Inhabits a diversity of habitat types.Nesting habitat ranges from scrubbychaparral to forested montane area,mostly on cliffs but also sometimes incavities in giant sequoia trees.Foraging occurs mostly in opengrassland.Wild condors court and nest betweenDecember and spring. They lay oneegg between late January and earlyApril. The egg hatches after 56 days.The chick is fed by its parents for 2months. When the chick is 2-3months old it leaves the nest but staysin the area to continue to be fed,though less frequently. Chicks beginto fly at 6-7 months of age. Juvenilesmay not be fully independent until upto a year after they begin to fly.Carcasses of dead animalsone to three days per week.Cattle, domestic sheep,mule deer, horses, andground squirrels. Deer arepreferred. Also prey onsmaller to medium sizedmammals includingcoyotes, rabbits, groundsquirrels, gray foxes, longtailed weasels, kangaroorats, Botta’s pocketgophers, and occasionally acoachwhip snake or aviancarrion.Whooping crane(Grus americana) – designated critical habitatMales: 1.5 m (5ft) and averageweight is 7.3 kg(16 lbs) for acaptive bird.Females: shorterand averageweight is 6.4 kg(14 lbs) for acaptive bird.2.3 m (7.5 ft)wingspanThree populations ofcranes exist in the wild:1) the Aransas WoodBuffalo Population(AWBP); 2) the FloridaPopulation (FP); and 3)the Eastern MigratoryPopulation (EMP). TheAWBP nests in theWood Buffalo NationalPark (WBNP) in theNorthwest Territories ofCanada and in Alberta,Canada. Thispopulation migratessouth to a stop overlocation inSummer: Marshes and prairiepotholes.Winter: Coastal marshes and prairies.The crane is a territorial nester andreturns to the same area each year.Eggs are laid from April to mid-May.Incubation last for a month. AWBPcranes migrate in the fall during aperiod beginning in mid-Septemberand ending by mid-November towinter at the Aransas NationalWildlife Refuge (ANWR). The EMPcranes migrate from late October toearly December. In spring, themigration begins between March 25and April 15. This migration takesless time than the fall migration (2-4weeks) and there is no known stopover. The EMP cranes leave theirwintering grounds between the end ofSummer: Larval andnymphal insects, frogs,rodents, berries, small birds,and minnows.Winter: Blue crabs, clams,and wolfberry.Migration: Wasteagricultural grains likebarley, and also frogs, fish,insects, tubers, and crayfish.Also eat acorns, snails,crayfish, and insects.35SizeCurrent RangeReproductiveHabitat TypeDietCycleMax. weightsobserved inDecember andJanuary andmin. weightsobserved in Julyand August.Captivewhooping cranechicks weigh100-150 g (0.2-0.3 lbs) whenthey hatch;1.75-2.50 kg(3.9-5.5 lbs) at40 days;4.30-4.95 kg(9.5-10.9 lbs) at100 days; and5.70-6.70 kg(12.6-14.8 lbs)(near adultweight) at 250days.Saskatchewan, beforeheading south througheastern MT, ND, SD,NE, KS, OK, and TX tothe wintering grounds ofAransas NationalWildlife Refuge(ANWR) on the GulfCoast of TX. The FP isnon-migratory andlocated on theKissimmee Prairie,south of Orlando inOsceola and Polkcounties. The EMP wasreintroduced to theNecedah NationalWildlife Refuge (NWR)in WI with captive birdstrained to migrate toChassahowitzka NWRon the Gulf Coast of FL.The AWBP is the onlyself sustaining wildpopulation. The FP andEMP are introduced andare designatedexperimental nonessential by theUSFWS.Februaryandmid-April.36SizeCurrent RangeReproductiveHabitat TypeDietCycleEskimo curlew(Numenius borealis) – no designated critical habitatLength:About 30 cm(11.8 inches)long with a billabout 5 cm (2.0inches) long.The lengthranges from 32cm (12.6inches) to 27 cm(10.6 inches).Weight:270-454 grams(0.6-1.0 lbs)The USFWS lists theEskimo curlew asstatewide in Alaska,Kansas, Montana, andNebraska, as well as infour counties inOklahoma, two countiesin South Dakota, andone county in Texas.Tundra and woodland transitionzones, consisting of dwarf shrubgraminoid tundra complex (“barrens”)and grassy meadows for breeding.Coastal and crowberry areas such asthose found in Labrador as well asterrestrial habitats were used to feedduring the fall migration. Salt marsh,intertidal flats, sand dunes, meadows,pastures, and old fields inMassachusetts. Ericaceous heathhabitat in Alaska, the NorthwestTerritories, northern Ontario, southernQuebec, Newfoundland, Labrador,and the Maritime Provinces.Tallgrass and eastern mixed-grassprairies, usually near a water source,and disturbed by fire or bison or infields under cultivation during springmigration. Burned prairies andwetlands, plowed fields, cloverpatches, and beaches.Migratory birds. Arrive at breedinggrounds in May. Breeding age is notknown, but related species breed ataround three years of age. Clutchesof eggs are laid from mid to late June.Eggs hatch from early to mid July andonly one brood is raised in a season.Chicks feed themselves beginning onthe first or second day post-hatch andmigrate at the end of the month.Breeding season is over by July andthe adults head south with juveniles tofollow. Migrate from July to Octoberand winter over in South America.Arrive at wintering grounds by earlySeptember. The return migration inthe spring begins in April or May.However, other sources report that thespring migration begins in lateFebruary, with the birds arriving inTexas and Louisiana by early March,and then heading north through theMidwestern states to eastern SouthDakota and then to breeding groundsin Canada by the end of May.Berries (blueberries andcrowberries), Dipteranlarvae and adult snails,coastal invertebrates(amphipods and isopods),earthworms, insects(beetles, younggrasshoppers, andgrasshopper eggs) beforethe fall migration. Ants onthe breeding grounds andant egg capsules duringspring migration. Grubsand cutworms. Otherspring migration foodconsisted primarily ofjuvenile grasshoppers andtheir larvae, particularly theRocky Mountaingrasshopper (now extinct),as well as other insects,berries, and earthworms.37SizeCurrent RangeReproductiveHabitat TypeDietCycleNorthern Aplomado falcon(Falco femoralis septentrionalis) – no designated critical habitatLength:35.6-45.7 cm(14-18 inches)in length with awingspan of78.7-101.6 cm(31-40 inches)Weight:410 grams (0.9lbs)USFWS lists thisspecies as occurringstatewide in Texas.Desert grasslands and coastal prairies.Open terrain with scattered trees orshrubs. Specifically in the U.S., thisspecies is found along yucca-coveredsand ridges in coastal prairies,riparian woodlands in opengrasslands, and in desert grasslandswith scattered mesquite and yucca.Essential habitat elements includeopen terrain with scattered trees,relatively low ground cover, anabundance of insects and small tomedium-sized birds, and a supply ofnest sites.Nesting occurs from March to June.The clutch size is generally 2 to 3eggs with a brood size of 1 to 3chicks. Incubation lasts 31 to 33days. Young birds leave the nestabout 4 to 5 weeks after hatching.Birds, insects, rodents,small snakes, and lizards.Black-footed ferret(Mustela nigripes) – no designated critical habitatAdult length:48.3-61.0 cm(19-24 inches),including a 12.7or 15.2 cm (5 or6 inch) tail.Adult weight:0.6-1.1 kg (1.4to 2.5 lbs)All wild populationshave been extirpated.Reintroduced intoseveral counties withinthe following states:Arizona, Kansas,Nebraska, New Mexico,North Dakota, SouthDakota, and Wyoming.Short midgrass prairie habitatconsistent with the North Americangrassland biome.Breeding takes place between Marchand May. Gestation lasts for 41-45days.Predominantly prairie dogsand prairie dog carrion.They also prey onlagomorphs, mice, voles,ground squirrels, pocketgophers, birds, and insects.38SizeCurrent RangeReproductiveHabitat TypeDietCycleChirichaua leopard frog(Rana chiricahuensis) – no designated critical habitat10.9 cm (4.3inches) inlength. Snoutto-vent lengthsof adults rangefromapproximately5.4 to 12.0 cm(2.1 to 4.7inches)Central and east-centralArizona into westcentral New Mexico,and also in southeasternArizona, the bootheel ofsouthwestern NewMexico, and souththrough westernChihuahua andnortheastern Sonora,MexicoHighly aquatic. Found in rockystreams with deep rock-bound pools,ponds, earthen stock tanks, andpermanent springs. Surroundingupland vegetation includes oak andmixed oak and pine woodlands, andranges into areas of chaparral,grassland, and desert. It is knownfrom montane and river valleycienegas, springs, pools, cattle tanks,lakes, reservoirs, streams, and rivers.It is a habitat generalist thathistorically was found in a variety ofaquatic habitat types, but is nowlimited to the comparatively fewaquatic systems that support few orno non-native predators. Permanentor semi-permanent pools are requiredfor breeding. Occurs at elevations of1,000 to 2,709 meters (3,281 to 8,890feet).Breeds primarily from April throughOctober, but egg masses are unusualin June. Populations that are greaterthan 1,798 meters (5,900 feet) breedfrom June-August. Tadpoles takethree to nine months tometamorphose, and some overwinter.At low elevations, the frog breedsfrom mid-February through June,while at higher elevations breedingoccurs from May until August.Larval stage is primarilyherbivorous (bacteria,diatoms, phytoplankton,filamentous green algae,water milfoil(Myriophyllumsp.),duckweed (Lemna minor),and detritus).Metamorphs and adults eata wide variety of aquatic orterrestrial invertebrates aswell as other arthropods andsmall fish, frogs, or toads.Other members of theleopard frog complex fromthe western United Stateseat a wide variety of preyitems including many typesof aquatic and terrestrialinvertebrates (e.g., snails,spiders, and insects) andvertebrates (e.g., fish, otheranurans (frogs and toads)(including conspecifics),and small birds). Freshwater shrimp may also beeaten.39SizeCurrent RangeReproductiveHabitat TypeDietCycleJaguar(Panthera onca) – no designated critical habitatLength:112-185 cm (44-72inches), plus atail length of45-75 cm (17.5-29 inches).Adult Weight:36.39-157.9 kg(80-348 lbs)Birth Weight:700-900 grams(1.5-2.0 lbs)The USFWS listsArizona (Cochise, Pima,and Santa Cruzcounties) and HidalgoCounty in New Mexicoas jaguar locations inthe U.S.In the humid tropics of CentralAmerica, the jaguar occupies wet,lowland habitat characterized byswampy savannas and tropical rainforests. The northern and southernreaches of current jaguar distributionare marked by far more arid habitatthan is found in the areas central tothe species’ distribution. Jaguars –particularly males of the northernreaches – are known to have largehome ranges that encompass a varietyof plant communities, including:Maderan evergreen-woodland,subalpine conifer forest, semidesertshrubland, and Sonoran desert scrub.Washes and riparian areas with densevegetative growth may also bevaluable movement corridors.In captivity breeding takes place yearround. However, there may be aspring mating season in the northernand southern limits of the species’range. Gestation lasts for 93-105days. In Mexico, most births occur inJuly, August, and September.Javelina, deer, livestock,capybara, paca, armadillo,caiman, and various speciesof turtle, birds, and fish.Gulf Coastjaguarundi(Herpailurusyagouaroundi cacomitli)– no designated critical habitatLength:55-77cm (21.7-30.3inches)(combined headand body) and atail length of33-60 cm (13.0-23.6 inches)Adult Weight:4.5-9.0 kg (9.9-19.8 lbs)26 counties in Texas.Chaparral plant communities anddense brushy areas near streams andrivers.Kittens are born around March orAugust. Kittens are weaned after 2months and within 10 months theyoung are fully independent.Gestation last between 70 and 75days.Small mammals, birds, andreptiles. Stomach contentshave included: lizards,rodents (mice and rats),small birds, and cottontailrabbits, and grass. Thisspecies may also prey onfish and other aquaticanimals.40SizeCurrent RangeReproductiveHabitat TypeDietCycleCanada lynx(Lynx Canadensis)– designated critical habitatLength:78.7-99.1 cm (31-39inches) snout totailAdult Weight:5.1-17.2 kg(11.2-37.9 lbs)Birth Weight:197-211 g (0.4-0.5 lbs)Listed by the USFWSas occurring in 15states: Alaska,Colorado, Idaho, Maine,Michigan, Minnesota,Montana, NewHampshire, New York,Oregon, Utah, Vermont,Washington, Wisconsin,and Wyoming.In the contiguous United States, thelynx is associated with the southern,transitional reaches of the cool andmoist boreal forest. Where it occursat these lower latitudes, the borealforest forms a mixed conifer andconifer-hardwood landscape. Morespecific lynx habitat associations varyfrom state to state.Mating takes place in February andMarch. The gestation period is 9-10weeks. Kittens are born between Mayand June, in litters of 1-8. Kittens areweaned after 5 months, althoughsome meat may be eaten by kittens asearly as the first month. Sexualmaturity is reached prior to two yearsof age.The snowshoe hare is thelynx’s primary prey. Ifsnowshoe hares are notavailable, the lynx will feedopportunistically on smallmammals and birds. Otherprey may include rodentsand fish. Lynx may alsoprey on ungulates.41SizeCurrent RangeReproductiveHabitat TypeDietCyclePreble's meadowjumpingmouse(Zapus hudsoniuspreblei)– designated critical habitatAdult Length:18.7-25.5 cm(7.4-10.0inches) with atail length of10.8-15.5 cm(4.3-6.1 inches).JuvenileWeight:<13 g(0.03 lbs)Sub-adultWeight:13-14 g(0.03 lbs)Adult Weight:14-38 g (0.03-0.08 lbs).These miceweigh more inlate August tomid-Septemberbeforehibernation andweigh less inMay when theyemerge fromhibernation.Widespread inWyoming but rare orextirpated in Colorado.Well developed riparian vegetationnext to undisturbed grassland, with awater source nearby that can range insize from a river to a small drainageof 1-3 meters (3.3-9.8 feet) wide.Seasonal streams, low moist areas,dry gulches, agricultural ditches, wetmeadows, and seeps near streams alsoprovide habitat.Trees, tall shrubs, short shrubs, anherbaceous layer, and ground coverare also necessary habitatcomponents.Upper limit of elevation is 2,360meters (7,742 feet) in Colorado and2,317 meters (7,601 feet) inWyoming.Day nests are constructed underdebris at the base of shrubs and treesor in open grasslands, made ofgrasses, forbs, sedges, rushes, andother plant material. The nests areusually above ground but can beunderground, are globular shapes ormats of litter, and are abandoned aftera week. These mice do not appear touse burrows of other rodents.Hibernate from September or Octoberuntil May. Adults hibernate by the 3rdweek in August, while the young ofthe year enter hibernation inSeptember or October.Meadow jumping mice have 2-3litters per year. Each litter has 2-8young, with an average of 5 young.The young mature to adult size in 4weeks. Mice born in June mayreproduce at 2 months of age andmice born later in the summerreproduce the following year.Arthropods and funguswhen they emerge fromhibernation.July-August: fungus, moss,and pollen.September: arthropodsLamb’s quarters, Russianthistle, sunflower, sedge,mullein, grasses,bladderpod, rushes, andseeds.42SizeCurrent RangeReproductiveHabitat TypeDietCycleOcelot(Leoparduspardalis)– no designated critical habitat11.3 - 15.8 kg(24.9-34.8 lbs)3 counties in Arizona(Cochise, Pima, andSanta Cruz) and 26counties in Texas.A variety of habitats can be used byocelots. Ocelots appear to use areasof dense cover, and in the northernpart of the range hunt in brushyforests and semi-arid deserts. In thesouthern part of its range, ocelothabitat includes tropical forests,mountain slopes, and pampas(grasslands).Births have been recorded fromSeptember to January. Births inTexas have been documented inSeptember and October, and also inlate summer, late fall, early winter,and late spring. Typically one or twokittens are born, but litters can rangeup to four kittens.Small to medium-sizedmammals (rabbits, agoutis,& mice), birds, reptiles(snakes & lizards), fish, &invertebrates.Mexican spotted owl(Strix occidentalis lucida)– designated critical habitatAdult maleaverage weight:519+32.6 (SD)g (1.1 lbs)Adult femaleaverage weight:579+31.2 (SD)g (1.3 lbs)13 counties in Arizona;33 counties in Colorado;22 counties in NewMexico; 4 counties inTexas; and 11 countiesin Utah.Old-growth or mature forests withunevenly aged stands of trees, highcanopy, multi-storied levels, and hightree density. Canyons with riparian orconifer communities. In Arizona andNew Mexico: mixed conifer, pineoak, Arizona cypress, oak woodlands,and associated riparian forests.Dispersing juveniles move through avariety of habitats before selecting ahome range, including: spruce-fir andmixed-conifer forests, pinyon-juniperwoodland, mountain shrublands,desert scrubland, and desertgrasslands.Owls defend their breeding territoryduring the nesting season (March –August). Clutch size: 1-3 eggs. Eggshatch in early May. A second clutchmay be produced if the first clutchfails. Owlets fledge at 4-5 weeks old(early to mid-June). They dispersefrom the nest in mid-September toearly October. Breeding is sporadic.Not all birds nest every year.Small- and medium-sizedrodents including woodrats,peromyscid mice, andmicrotine voles. They alsoeat bats, birds, reptiles, andarthropods.43SizeCurrent RangeReproductiveHabitat TypeDietCyclePiping plover(Charadrius melodus) – designated critical habitatBetween 42 and64 grams (1.5 to2 ounces)17 centimetersfrom bill torump, and itswings measureapproximately35 centimetersfrom tip to tipPlover breeding occursin Montana in Garfield,Sheridan and McConeCounties. In NorthDakota, plovers breed in25 counties locatedalong the MissouriRiver and in the alkaliwetlands located in thecenter of the state.Plover breeding inSouth Dakota alsooccurs on sandbarsalong the MissouriRiver, with otherisolated nesting siteslocated in Lake Oaheand saline wetlands inthe northeast. InNebraska, plover breedalong the upperMissouri River, thelower Niobrara, and themid- to lower PlatteRivers, as well as theMiddle Loup and LoupRivers, and LakeMcConaughy (USFWS,1988).In north-central North America,Piping Plovers nest on barren sandand gravel Great Lakes shorelines,and along sand and gravel shores ofrivers and lakes in the Great Plains.Lake habitat generally consists ofwide beaches (>20 m) with less than5% vegetative cover, with highlyclumped vegetation and/or withextensive gravel. Lake habitat mayvary from these conditions whenunavailable in a given shoreline area.Plovers arrive at breeding sites in theGreat Plains between mid-April andmid-May. Egg laying begins thesecond or third week of May.Incubation lasts for 25-31 days andboth adults incubate the egg. Chicksfledge between 21 days after hatchingin Manitoba to 30-35 days on LongIsland in New York. Adults migratefrom breeding grounds beginning inmid-July and ending in early August.Juveniles often depart as late as lateAugust and breeding males aresometimes reported to depart withtheir youngThe diet of the pipingplover consists ofinvertebrates such as marineworms, fly larvae, beetles,crustaceans, and mollusks44SizeCurrent RangeReproductiveHabitat TypeDietCycleNew Mexican ridge-nosed rattlesnake(Crotalus willardi obscurus) – designated critical habitatLength:Maximumlength of 60 cm(24 inches).The lengthsrange from 30-61 cm (11.8-24inches).Weight:85-113 grams(0.2-0.3 lbs).Exists in fragmentedenclaves occupying acombined total of lessthan two square miles ofhabitat in the extremesouthwest corner ofNew Mexico. TheUSFWS lists the speciesas known to occur intwo counties in theU.S.: Hidalgo County,New Mexico andCochise County,Arizona.Narrow mountain canyons atelevations between 1,676 and 2,743meters (5,500 and 9,000 feet). Thesnake prefers to hide in leaf litteramong cobbles and rocks alongcanyon floors. Rocks, leaf litter, andmesic conditions are commonalitiesamong all confirmed habitat of thisspecies. The vegetative structure ofthe habitat is chiefly comprised ofopen stands of pine-oak forest andassociated shrubs and grasses.Specifically, plant species of thetypical habitat include Arizona whiteoak, Alligator juniper, Mexicanpinyon, Chihuahua pine, Gambel oak,Arizona Madrone, skunkbush,Manzanita, and birchleaf rhamnus.Bunchgrass is also associated withthis species.Females are ovoviviparous, and givebirth to live young. This species is abiennial species: mating occurs in thesummer and fertilized eggs areretained in the oviducts until ready tohatch the following summer. Thegestation period averages 13 months.Births for most species of rattlesnakeoccur between August 1stand October15th, however most births of thisspecies are in April and May.Small mammals, birds,lizards, other snakes, andarthropods. Diets of smallbodied rattlesnakesincluding this speciesgenerally consist more oflizards than smallmammals. Natural feedingof this species mightinclude scavenging ascaptive individuals havebeen known to consumecarrion.45SizeCurrent RangeReproductiveHabitat TypeDietCycleSonora tiger salamander(Ambystoma tigrinum stebbinsi) – no designated critical habitatMetamorphosedSonora tigersalamanders:4.5-15 cm (1.8-5.9 inches)snout to ventlength.Branchiateadults: 6.5-16.5cm (2.6-6.5inches) snout tovent length.This subspecies hasbeen found in 53 pondsin the San Rafael Valleyof Arizona. The SanRafael Valley liesbetween the Hauchucaand Patagoniamountains, is borderedby the Canelo Hills tothe north and extendsfrom Santa Cruz Countyin Arizona south forapproximately 30 km(18 miles) into Sonora,Mexico.Requires standing water from Januarythrough June for breeding and larvalgrowth. Adult, metamorphosedsalamanders inhabit adjacentgrassland and oak woodlandterrestrial habitat when not in ponds.The ecology of the Sonora tigersalamander outside of the pond hasnot been well studied, but otherAmbystoma species spend much oftheir time in mammal burrows orburied in soft earth to avoidenvironmental extremes common onland.Begin as eggs laid in water. Thenhatch and grow as aquatic larvae withgills, and then either mature as gilledaquatic adults (called branchiateadults, neotenes, or paedomorphs), ormetamorphose into terrestrialsalamanders without gills. Breed asearly as January, and eggs can befound in ponds as late as early May.Terrestrial adults, which are oftenoutside of the pond during the rest ofthe year, return to the ponds to breed,and branchiate adults in the pond alsobreed. Eggs take 2-4 weeks to hatch;the colder the water the longer it takesthe eggs to develop. Larvae candevelop into the minimum sizenecessary to metamorphose in as fewas two months. However, becausemany sites hold water all year, larvaeoften remain in the water longerbefore metamorphosing, or instead,develop into branchiate adults.Larvae:zooplankton(daphnids, copepods,bosminids, ostracods, etc.),and incorporate largeraquatic macroinvertebrates(chironomids, trichopterans,mollusks, zygopterans, etc.)as they grow.Branchiate adults:zooplankton and a varietyof macroinvertebrates, andsalamander eggs and larvaeduring the breeding season.Metamorphosed adults:while still in the pond theyeat aquatic macroinvertebrates & terrestrialinsects that fall in the water.Once outside the pond theyeat terrestrial insects andother macroinvertebrates.46SizeCurrent RangeReproductiveHabitat TypeDietCycleBlack-capped vireo(Vireo atricapilla) – no designated critical habitatLength:11 to 12 cm(about 4.5inches)Weight:9 to 10 grams(0.02 lbs)The USFWS websitestates that the species isknown to occur in 8counties in Oklahomaand 67 counties in TX.However, the USFWSrecovery plan statesthree locations (Blaine,Comanche, and theborder of Canadian andCaddo counties) inOklahoma and 35counties in Texas.Mixed deciduous/evergreen shrubland. Breeding vireos use shrubbygrowth of irregular height anddistribution with spaces the smallthickets and clumps and withvegetative extending to ground level.From Oklahoma through most ofTexas this type of vegetationalconfiguration occurs most frequentlyon rocky substrates with shallowsoils, in rocky gullies, on edges ofravines, and on eroded slopes.Territory size mostly 2-4 acres.Nesting begins when females arriveand continues through August. Nestbuilding requires 2-5 days. Completeclutches have been found as early asApril 4thin Texas and April 30thinOklahoma. Latest known nestingstart (beginning nest construction) isJuly 21st. Clutches contain 3-4 eggs.Seasonal clutch size is likely between12 and 20 eggs allowing up to sixnesting attempts per season. One eggis laid per day with the first egg beinglaid one day after completion of thenest. Incubation requires 14-19 days.Nestling stage is 9-12 days. Fledglingstage is 30-45 days.These birds areinsectivorous. Beetles andcaterpillars make up a largepart of the diet.Golden-cheeked warbler(Dendroica chrysoparia) – no designated critical habitatLength:12 cm (4.7inches) longWeight:10 grams (0.02lbs)Nests only in centralTexas. Edwards Plateauof Texas and locallynorth to Palo PintoCountyMixed Ashe-juniper and oakwoodlands in ravines and canyons.Summers in open canopy forest andwinters in closed canopy forests.Breeds in juniper-oak woodlandstypically in limestone hills andcanyons. It is dependent on the barkof the Ashe juniper (Juniperus ashei)for nesting materials. In winter itoccurs in pine-oak forests atelevations between 1,500 and 3,000meters (4,921 and 9,842 feet).One brood with incubation of 12 daysand 9 days until fledge. Arrives onbreeding ground in early March. Nestbuilt by female and usually in anAshe juniper tree. Nests areconstructed from strips of juniperbark woven together with spider silkand insect cocoons, and lined withgrass, hair, or down. 3-5 eggs areincubated for 10-12 days. Youngleave the nest at 9-12 days. Youngare independent at about 1 monthafter fledging. Migration to thewintering grounds occurs from Juneto August.These birds areinsectivorous. Feeds oninsects and spiders withcaterpillars being animportant prey item duringthe breeding season. Preyis taken directly fromfoliage or snatched from theair. Less is known aboutthe winter diet.4748SizeCurrent RangeHabitat TypeReproductiveCycleDietGraywolf(Canis lupus)– designated critical habitatAdult weight:18-80 kg (40-175 lbs)Found in: Colorado(statewide), Michigan(15 counties), NewMexico (3 counties),North Dakota (53counties), Oregon(statewide), SouthDakota (statewide),Utah (statewide),Washington (statewide),and Wisconsin (32counties).Wide range of habitats includingtemperate forests, mountains, tundra,taiga, and grasslands.Typically only the alpha male andfemale breed and produce pups.Breeding begins around age 2 andmay continue annually until they are10 years old or older. Pups are bornin April. Litter size ranges from 1-11pups with an average of 5 pups perlitter.White-tailed deer, muledeer, moose, elk, caribou,bison, muskox, bighornsheep, Dall sheep, mountaingoat, beaver, and snowshoehare. Small mammals,birds, and largeinvertebrates are sometimesalso taken.

### 2.5.1. Consi deration of Federally Listed Plants

BTPDs may have an effect on th e plant communities within thei r habitat through their feeding habits. Eliminating or reducing the numbers of BTPDs may therefore have an effect on the composition of plant communities within the range of the BTPD. The impact of this effect to listed plants while noted, is not specifically asse ssed since it is not clear whether such changes would have negative or positive effects on individual listed plant species. Further, impacts from the use of Rozol Prairie Dog Bait to pollinators and seed dispersers could have effects on the viability of listed plants that depend upon t hose methods of reproduction. Listed plants found within the 10 states where Rozol Prairie Dog Bait may be used are enumerated below:

Penland beardtongue ( Penstemon penlandii ) , Colorado butterfly plant ( Gaura neomexicana var.

coloradensis ), Chisos Mountain hedgehog cactus ( Echinocereus chisoensis var. chisoensis ),

Knowlton's cactus ( Pediocactus knowltonii ) , Kuenzler hedgehog cactus ( Echinocereus fendleri
var. kuenzleri ) , Lee pincushion cactus ( Coryphantha sneedii var. leei ) , Lloyd's Mariposa Cactus ( Echinomastus mariposensis ) , Mesa Verde cactus ( Sclerocactus mesae-verdae ) , Nellie cory

cactus ( Coryphantha minima ) , Sneed pincushion cactus ( Coryphantha sneedii var. sneedii )

, Tobusch fishhook cactus ( Ancistrocactus tobuschii ) , Spalding's catchfly ( Silene spaldingii ), Terlingua Creek cat's-eye ( Cryptantha crassipes ) , bunched cory cactus ( Coryphantha ramillosa )

, Zuni fleabane ( Erigeron rhizomatus ) , Holy Ghost Ipomopsis ( Ipomopsis sancti-spiritus ), Ute ladies'-tresses ( Spiranthes diluvialis ), Mancos milk-vetch ( Astragalus humillimus ) , Osterhout

milk-vetch ( Astragalus osterhoutii ) , Penland alpine fen mustard ( Eutrema penlandii ) , Hinckley oak ( Quercus hinckleyi ), western prairie fringed orchid ( Platanthera praeclara ), Todsen's pennyroyal ( Hedeoma todsenii ), blowout penstemon ( Penstemon haydenii ), North Park phacelia ( Phacelia formosula ) , Davis' green pitaya ( Echinocereus viridiflorus var. davisii ) , Sacramento prickly poppy ( Argemone pleiacantha ssp. pinnatisecta ) , Texas poppy-mallow ( Callirhoe

scabriuscula ) , slender rush-pea, ( Hoffmannseggia tenella ) , Texas snowbells ( Styrax texanus )

, Pecos sunflower ( Helianthus paradoxus ) , Sacramento Mountains thistle ( Cirsium vinaceum )

, gypsum wild-buckwheat ( Eriogonum gypsophilum ) , and desert yellowhead ( Yermo xanthocephalus ).

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### 2.6. Designated Critical Habitat

Critical habitat has been designated for the follo wing nine assessed animal species: Salt Creek tiger beetle, California condor, w hooping crane, Canada lynx, Preb le’s meadow jumping mouse, Mexican spotted owl, piping plover, New Mexican ridge-nosed rattlesnake, and the gray wolf.

Critical habitat is defined in the ESA as the geog raphic area occupied by the species at the time of the listing where the physical and biological features necessary for the conservation of the species exist, and there is a need for special ma nagement to protect the listed species. It may also include areas outside the occupied area at th e time of listing if such areas are ‘essential to the conservation of the species.’ Critical habi tat receives protection unde r Section 7 of the ESA through prohibition against destruction or advers e modification with regard to actions carried out, funded, or authorized by a federal agency. S ection 7 requires consu ltation on federal actions that are likely to result in the destruction or adverse modification of critical habitat.

To be included in a critical habitat designation, the habitat must be ‘esse ntial to the conservation of the species.’ Critical habita t designations identify, to the ex tent known using best scientific and commercial data available, habitat areas that provide essential life cy cle needs of the species,

or areas that contain certain PC Es (as defined in 50 CFR 414.12(b)). PCEs include, but are not limited to, space for individual and population grow th and for normal behavior; food, water, air, light, minerals, or other nutriti onal or physiological requirements ; cover or shelter; sites for breeding, reproduction, rearing (or de velopment) of offspring; and habitats that are protected from disturbance or are representative of the hist oric geographical and ec ological distributions of a species. Table 2.3 describes the PCEs for the critical habitats for the following nine assessed species: Salt Creek tiger beetle, California c ondor, whooping crane, Canada lynx, Preble’s meadow jumping mouse, Mexican spotted ow l, piping plover, New Mexican ridge-nosed rattlesnake, and the gray wolf.

Table 2.3 Designated Cr itical Habitat PCEs

PCEs Reference

Salt Creek tiger beetle
(1) Non-vegetated streambanks and mid-channel areas, located adjacent to and between saline stream edges and barren salt flats in saline and freshwater wetlands, in assemblages that are within 4 mi (6 km) of one another.
(2) Moist, barren salt flats with:
(a) Salmo and Saltillo soils or Lamo, Gibbon-Sa ltine, Obert, and Zoe soils with Salmo and

Saltillo inclusions:
(b) Soil electroconductivity ranging from 2,016.0 mS/m to 2,992.2 mS/m;

(c) Soil moisture ranging from 43.5 percent to 51.7 percent; and
(d) Differential hydraulic pressures that create evaporation and result in exposed salt on soil

surfaces. (3) A natural hydrologic regime resulting in annua l high flows in saline streams in the early spring and summer, and natural elevation changes in groundwater levels to hydrate saline wetlands located on the floodplain. (4) The presence of abundant and diverse flyi ng and non-flying invertebrate prey species belonging to the orders Coleoptera, Orthoptera, Hemiptera, Hymenoptera, Odonata, Diptera, or Lepidoptera. (USFWS, 2010)



### 50California condor
PCEs were not described for the California condor. However, several factors were considered in designating critical habitat: The Sespe-Piru, Mantilija, Sisquoc-San Rafael , and the Hi Mountain-Beartrap areas were considered critical for nesting and related year-long activities. The Mount Pinos and Blue-Ridge areas were considered critical for roosting. The Tejon Ranch, Kern County Rangelands, and Tulare County Rangelands were considered critical for feeding and other related activities; specifically, the Tejon County Rangelands are important because it is the only feeding area close to the Sespe-Piru nesting area. Further, areas of open range with limited distur bance that provide food are needed within the designated areas to maintain the species, since food availability is directly related to condor distribution and reproduction. (USFWS, 1976)

Whooping crane Although PCEs were not specifically described for the whooping crane it was stated that each of the five factors normally associated with PCEs ((1) Sp ace for individual and population growth and for normal behavior; (2) Food, water, air, light, minerals, or other nutritional or physiological requirements; (3) Cover or shelter; (4) Sites for breeding, reproduction, or rearing of offspring; and generally, (5) Habitats that are protected from disturbances or are representative of the geographical distribution of the listed species) pertain to the whooping

crane and are summarized below: Whooping cranes are territorial; pairs require hundreds of acres of undisturbed wetland habitat and unmated birds require undefended territory. Refuges in Idaho, Colorado, and New Mexico were originally designated as part of the critical habitat to add space for a growing new flock. However, these refuges were later removed fr om the critical habitat designation due to the failure of whooping crane re introduction in these areas. (USFWS,1978 and 1997)

All of the designated critical habitat areas provi de for the nutritional and physiological needs

of the cranes. This includes the tidal flats an d marshes of Aransas that provide crustaceans and mollusks, the spring migration marshes that provide frogs, fish, crayfish, and other small animals, and the fall migration stopover locations where cranes feed primarily on waste grains

and insects. Whooping cranes require open sp aces, primarily sand and gravel bars in rivers and lakes, for nightly roosting. These features appear to be one of the major factor s in the selection of habitat by cranes. With regard to breeding, the Grays Lake National Wildlife Refuge in Idaho was previously designated as critical habitat in order to provide additional nesting habitat. However, all of the designated critical habitat provides areas essential to rearing young. Cranes also require undisturbed wetland roosting sites and do not tolerate disturbance to themselves or their

habitat. (USFWS, 1978)

Canada lynx
Boreal forest of multiple succesional stages.
Snowshoe hares and their preferred habitat conditions, which include low and dense vegetation that protrudes above the snow, an d mature multistoried stands with conifer boughs at the snow

surface.
Winter snow conditions of deep powder present for extended periods of time.

Potential den sites characterized by abundant coarse woody debris.
Matrix habitat (e.g., hardwood forest, dry forest, non-forest, or other habitat types that do not support snowshoe hares) which connect patches of boreal forest foraging sites used by the lynx within a home range (USFWS, 2009)



### 51Preble’s meadow jumping mouse
Riparian corridors formed and maintained by normal, dynamic, geomorphological, and hydrologic processes that create and maintain river and stream channels, floodplains, and floodplain benches and promote patterns of vegetation favorable to the Preble’s meadow jumping mouse, containing dense, riparian vegetation consisting of grasses, forbs, and shrubs, or any combination thereof, in areas along rivers and streams, that normally provide open water through the mouse’s active season. The riparian areas must also include specific movement corridors that provide connectivity between and within populations. These could be riparian corridors with less vegetative cover, or include human disturbances such as erosion control, travel ways under bridges, along ditches and canals, and through

culverts. Adjacent areas of low disturbance in floodplains and uplands, such as hayed fields, grazed pasture, and other unplowed agricultural fields, re stored mine lands, recreational trail areas and

urban-wildland interfaces. (USFWS, 2009)

Mexican spotted owl
A range of tree species, including mixed conifer, pine-oak, and riparian forest types, composed of different tree sizes reflecting different stages of trees, 30-45% of whic h are trees with a 12 inch or greater tr unk diameter when measured 4.5 feet off of the ground.
A shade canopy created by the tree branches covering 40 percent or more of the ground
Large dead trees (snags) with a trunk diameter of at least 12 inch es (0.3 meters) when measured at 4.5 feet (1.4 meters) from the ground.
High volumes of fallen trees and other woody debris;
A wide range of tree and plant species, including hardwoods; and
Adequate levels of residual plant cover to maintain fruits, seeds, and allow plant regeneration.
Presence of water which typically provides cool er temperatures and higher humidity than the nearby areas.
Clumps of stringers of mixed-conifer, pine-oak, pinyon-juniper, and/or riparian vegetation;
Canyon wall containing crevices, ledges, or caves; and
High percent of ground litter and woody debris. (USFWS, 2004)

Piping plover
The PCEs that support foraging, roosting, and sheltering habitat components for the wintering piping plover are: (1) Intertidal sand beaches (including sand flats) or mud flats (between the MLLW [mean lower low water] and annual high tide) with no, or very sparse, emergent vegetation for feeding. In some cases, these flats may be covered or partially covered by a mat of blue-green algae. (2) Unvegetated or sparsely vegetated sand, mud, or algal flats above annual high tide for roosting. Such sites may have debris or detritus and may have micro-topographic relief (less than 20 in (50 cm) above substrate surface) offering refuge from high winds and cold weather.
(3) Surf-cast algae for feeding.
(4) Sparsely vegetated backbeach, which is the b each area above mean high tide seaward of the dune line, or in cases where no dunes exist, seaward of a delineating feature such as a vegetation line, structure, or road. Backbeach is used by plovers for roosting and refuge during

storms. (5) Spits, especially sand, running into water used for foraging and roosting.
(6) Salterns, or bare sand flats in the center of mangrove ecosystems that are found above mean high water and are only i rregularly flushed with seawater. (7) Unvegetated washover areas with little or no topographic relief for feeding and roosting.

Washover areas are formed and ma intained by the action of hurricanes, storm surges, or other

extreme wave actions. (8) Natural conditions of sparse vegetation and little or no topographic relief mimicked in artificial habitat types (e.g ., dredge spoil sites.) (USFWS, 2009)



### 52The following PCEs, taken from the critical hab itat designation for the northern Great Plains breeding population of the piping plover, encompass piping plover habitat outside of the designated wintering grounds of the species. The one overriding primary constituent element (biological) that must be present at all sites is the dynamic ecological processes that create and maintain piping plover habitat. The biological primary constituent element, i.e. , dynamic ecological processes, creates different physical primary constituent elements on the landscape. These habitat types or physical primary constituent elements that sustain the northern Great Plains breeding population of piping plovers are described as follows:
On prairie alkali lakes and wetlands, the physi cal primary constituent elements include –
(1) Shallow, seasonally to permanently flooded, mixosaline to hypersaline wetlands with sandy to gravelly, sparsely vegetated beaches, salt-en crusted mud flats, and/or gravelly salt flats;
(2) Springs and fens along edges of alkali lakes and wetlands; and
(3) Adjacent uplands 200 feet (61 m) above the high water mark of the alkali lake or wetland.
On rivers the physical primary constituent elements include – sparsely vegetated channel sandbars, sand and gravel beaches on islands, temporary pools on sandbars and islands, and the

interface with the river. On reservoirs the physical primary constituent elements include – sparsely vegetated shoreline beaches, peninsulas, islands composed of sand, gr avel, or shale, and their interface with the

water bodies. On inland lakes (Lake of the Woods) the physical primary constituent elements include – sparsely vegetated and windswept sandy to grave lly islands, beaches, and peninsulas, and their interface with the water body. (USFWS, 2002)

New Mexican ridge-nosed rattlesnake

PCEs were not described for the New Mexican ri dge-nosed rattlesnake by name. However, the critical habitat listing notice identified certain attr ibutes and features of the designated critical habitat area that are grouped as “constituent elements,” including:
Dens and/or denning habitat that provides shelter during the summer and winter months;
Vegetation that provides cover for the New Me xican ridge-nosed rattlesnake and habitat for

prey; Abundance of prey (lizards and rodents) (USFWS, 1978)

Gray wolf
PCEs were not described for the gray wolf. However, key habitat components were described in the recovery plan:
A year-round abundance of ungulate prey and alternate prey,
Secluded and suitable denning and rendezvous sites, and
Sufficient space with low human disturbance. (USFWS, 1987)



### 2.7. Action Area and LAA Eff ects Determination Area

2.7.1. Action Area

The action area is defined by the Endangered Species Act as, “all areas to be affected directly or indirectly by the Federal action and not merely the immediate ar ea involved in the action” (50 CFR §402.2). The Federal action is the authorization or registrati on of pesticide use or uses as described on the label(s) of pe sticide products containing a partic ular active ingredient. Based on an analysis of the Federal action, the action area is defined by the actual and potential use of the pesticide and areas where that use could result in effects. Specific measures of ecological effect for the assessed species that define the action area include any direct and i ndirect toxic effect to

53

### the assessed species and any potenti al modification of its critical habitat, including reduction in survival, growth, and reproduction as well as the full suite of subl ethal effects available in the

effects literature. The overal l action area for the na tional registration of chlorophacinone is likely to encompass considerable portions of the United States based on the large array of agricultural and non-agri cultural uses. However, the sc ope of this assessment limits

consideration of the overall action area to reflect the BTPD use pattern and the potential for this use to affect listed species.

For this assessment, BTPD range within the states of Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, Sout h Dakota, Texas and Wyoming and counties adjacent to this range is considered to be the action area. The action area considered for direct effects includes the BTPD range within the 10 stat es listed above as well as counties adjacent to this range. The action area considered for indire ct effects includes only the BTPD range with the

10 states listed above and does not include counties adjacent to this range. This distinction was made because indirect effects are not expected to extend beyond the use area. However, direct effects may extend beyond the use area due to exposure to individua ls or via prey items with chlorophacinone residues that could be found outside of their described range.

It is important to note that the historic range-w ide action areas do not imply that direct and/or

indirect effects and/or critical habitat modification are expected or are likely to occur over the full extent of the action area, but rather to iden tify all areas that may potentially be affected by the action. The Agency uses more rigorous anal ysis including consideration of available land cover data, toxicity data, and exposure informati on to determine areas wh ere listed species and their designated critical habitats may be aff ected or modified via endpoints associated with reduced survival, growth, or reproduction.

2.7.2. MA Effects Determination Area

A stepwise approach is used to define the May Affect (MA) Effects Determination Area. A MA effects determination applies to those areas where chlorophacinone use may directly or indirectly affect the species and/or modify its designated critical habitat. As a result, this is the area where the BTPD range overlaps with the range and/or desi gnated critical habitat for the listed species. If there is no overlap between the BTPD range and the habitat or occurrence areas of the listed species and the listed species is not found in a county adjacent to the BTPD range then a no

effect “NE” determination is made. Counties adjacent to the BTPD ra nge are considered to account for potential migration of lis ted species out of their historic ranges. However, for habitat modification effects, adjacent counties will not be c onsidered. The first step in defining the MA

Effects Determination Area is to understand the fe deral action. The federal action is defined as the use of 50 mg a.i./kg-bait chlorophacinone gr ain bait to control BTPDs on rangelands and noncrop areas within the noted 10 state area. An analysis of this use and review of the product label was completed.

Following a determination of the assessed use, an evaluation of the potential “footprint” of chlorophacinone use for BTPDs ( i.e ., the area where pesticide application may occur) is determined. This “footprint” represents the ini tial area of concern and comes from the range of

54

### the BTPD obtained from NatureServe. The init ial area of concern is defined as all land cover types within the rang e of the BTPD.

Figure 2.2. Initial area of concern, or “footprin t” of potential use, for chlorophacinone use

to control BTPDs.

As previously discussed, the action area is define d by the most sensitive measure of direct and indirect ecological toxic effect s including reduction in survival , growth, reproduction, and the

entire suite of sublethal effect s from valid, peer-reviewed studie s. Once the initial area of concern is defined, the next st ep is to define the boundaries of the potential MA Effects

55

### Determination Area by determining the extent of offsite transport via chlorophacinone exposed animals ranging distances from chlorophacinone use sites. The Agency does not have a method for modeling this type of off-site transport but will include listed species not just overlapping in the range of the BTPD but thos e species occurring in counties adjacent to counties within the historic BTPD range as well.

2.8. Assessment Endpoints and Measures of Ecological Effect

2.8.1. Assessment Endpoints

A complete discussion of all of the toxicity da ta available for this risk assessment, including resulting measures of ecological effect selected for each taxonomi c group of concern, is included

in Section 4 of this document. Registrant submitted data, data from ECOTOX, and data received during the comment period for “Receipt of Petitio n Requesting EPA to Suspend the Registration of Rozol Prairie Dog Bait and Cancel Cert ain Application Sites” (EPA-HQ-OPP-2009-0684- 0001) were all considered. Table 2.4 identifies the taxa relevant to assessing direct effects via primary or secondary exposure for each species of concern. The taxa relevant to primary exposure are those animals that directly consume the chlorophacinone bait. The taxa relevant to secondary exposure are those sp ecies of concern that prey upon or scavenge the primary consumers of the cholorphacinone bait.

Table 2.4 Taxa Used in the Analyses of Dire ct Effects from Primar y (Bait) and Secondary Exposure for the Listed Species that May be Affected

Listed Species Terrestrial

Invertebrates Mammals Birds

Grizzly bear N/A Primary and Secondary N/A

American burying beetle Secondary Seconda ry Secondary

Salt creek tiger beetle Secondary N/A N/A

California condor N/A Secondary Secondary

Whooping crane Secondary Secondary Primary and Secondary

Eskimo curlew Secondary N/A N/A

Northern Aplomado falcon Secondary Seconda ry Secondary

Black-footed ferret Secondary Seconda ry Secondary

Chirichaua leopard frog Secondary N/A Secondary

Jaguar N/A Secondary Secondary

Gulf Coast jaguarundi N/A Secondary Secondary

Canada lynx N/A Secondary Secondary

Preble’s meadow jumping mouse Secondary Primary N/A

Ocelot Secondary Seconda ry Secondary

Mexican spotted owl Secondary Seconda ry Secondary

Piping plover Secondary N/A N/A

New Mexican ridge-nosed rattlesnake Secondary Secondary Secondary

Sonora tiger salamander Secondary N/A N/A

Black-capped vireo Secondary N/A N/A

Golden-cheeked warbler Secondary N/A N/A

Wolf, Gray Secondary Seconda ry Secondary
N/A Not Applicable



### 56

### The taxa used to assess the potential for indire ct effects from the uses of chlorophacinone for each listed species are indentified in Table 2.5. Indirect effects consist of modifications to critical habitat or loss of pr ey base. The specific assessment endpoints used to assess the potential for direct and indi rect effects to each listed species are provided in Section 2.1.

Table 2.5 Taxa Used in the Analyses of Indirect Effects for the Listed Species that May be

Affected
Listed Species Terrestrial

Invertebrates Mammals Birds

Grizzly bear N/A loss of prey base N/A American burying beetle loss of prey base loss of prey base loss of prey base Salt creek tiger beetle loss of prey base N/A N/A

California condor N/A loss of prey base loss of prey base Whooping crane loss of prey base loss of prey base loss of prey base

Eskimo curlew loss of prey base N/A N/A Northern Aplomado falcon loss of prey base loss of prey base loss of prey base

Black-footed ferret loss of prey base loss of prey base and habitat loss of prey base Chirichaua leopard frog loss of prey base N/A loss of prey base Jaguar N/A loss of prey base loss of prey base Gulf Coast jaguarundi N/A loss of prey base loss of prey base Canada lynx N/A loss of prey base loss of prey base Preble’s meadow jumping

mouse loss of prey base N/A N/A

Ocelot loss of prey base loss of prey base loss of prey base Mexican spotted owl loss of prey base loss of prey base loss of prey base Piping plover loss of prey base N/A N/A New Mexican ridge-nosed

rattlesnake loss of prey base loss of pr ey base loss of prey base

Sonora tiger salamander loss of prey base N/A loss of habitat Black-capped vireo loss of prey base N/A N/A

Golden-cheeked warbler loss of prey base N/A N/A Wolf, Gray loss of prey base loss of pr ey base loss of prey base N/A Not Applicable

1 EFED uses avian toxicity data to assess for expo sure to and risks from reptiles and amphibians.



### 57

### Table 2.6 identifies the most conservative toxic endpoi nts relevant to each taxa and the most conservative residue concentrations. These endp oints and concentrations will be carried through the assessment to quantitatively asse ss risk to the species listed in Table 2.4 and Table 2.5.

Table 2.6 Taxa and Assessment Endpoints Used to Evaluate the Potential for Use of Chlorophacinone to Result in Direct and I ndirect Effects to the Listed Species or Modification of Critical Habitat that May be Affected

Taxa Used to Assess

Direct and Indirect

Effects to Listed Species and/or

Modification to

Critical Habitat or

Habitat Direct or

Indirect Effect

to Listed Species Assessment Endpoints Measures of Ecological Effects Measures of Ecological Exposures

1. Mammals Direct and

Indirect Effect Survival, growth, and reproduction of individuals

or modification of critical

habitat via direct and

indirect effects Primary Exposure:

Most sensitive mammal

acute LD 50 (5-day) 1 : Norway rat LD 50 = 0.80 mg a.i./kg-bw 2 Secondary Exposure: Highest whole body BTPD average concentration (MRID 47333603): BTPD= 2.24 mg a.i./kg-bw and highest whole body

non-target average
concentration (Anonymous, 1981): Deer Mouse = 5.8 mg a.i./kg-bw

2. Birds and Herptiles Direct and

Indirect Effect Survival, growth, and reproduction of individuals

or modification of critical

habitat via direct and

indirect effects Primary Exposure:

Most sensitive bird

LC 50 (MRID 41513102): Bobwhite

LC 50 = 56 mg a.i./kgdiet 2

Bobwhite LD 50 = 258 mg a.i./kg-bw Secondary Exposure: Highest whole body BTPD average concentration (MRID 47333603): BTPD= 2.24 mg a.i./kg-bw and highest whole body

non-target average
concentration (Anonymous, 1981): Deer Mouse = 5.8 mg a.i./kg-bw

3. Terrestrial

Invertebrates Direct and

Indirect Effect Survival, growth, and reproduction of individuals

or modification of critical

habitat via direct and

indirect effects Secondary Exposure: Unquantified sublethal

effects to Nicrophorus

orbicollis (MRID 47383001)

1 Jackson, W.B. and A.D. Ashton. 1992. A review of available anticoagulants and their use in the

United States. Proc. Vertebr. Pest Conf. 15:156-160..

2 The most sensitive endpoint was used in calculations and is displayed in bold font.



### 58

### 2.8.2. Assessment Endpoints for Desi gnated Critical Habitat

As previously discussed, designated critical habitat is assessed to evaluate actions related to the use of chlorophacinone to control BTPDs that may alter the PCEs of the listed species’ designated critical habitat. PCEs for the li sted species were prev iously described in Section 2.6

. Actions that may modify critic al habitat are those that alte r the PCEs and jeopardize the continued existence of the listed species. Therefore, these actions are identified as assessment endpoints. It should be noted th at evaluation of PCEs as assessm ent endpoints is limited to those of a biological nature ( i.e ., the biological resource requirements for the listed species associated with the critical habitat) and those for which chlorophacinone effects data are available.

Assessment endpoints used to evaluate potential for direct and indirect eff ects are equivalent to the assessment endpoints used to evaluate potential effects to designa ted critical habitat. If a potential for direct or indirect effects is found, then there is also a potential for effects to designated critical habitat. Some components of these PCEs are associated with physical abiotic features ( e.g ., presence of a water body, limits of species ranges or physical geographic features), which are not expected to be measurably altered by use of pesticides.

2.9. Conceptual Model

2.9.1. Risk Hypotheses

Risk hypotheses are specific assumptions about potential adverse effects ( i.e., changes in assessment endpoints) and may be based on theory and logic, empirical data, mathematical models, or probability models (USEPA, 1998). For this assessment, the risk is stressor-linked, where the stressor is chlorophacinone bait pl aced in BTPD burrows. The following risk hypotheses are presumed in this assessment:

The labeled use of chlorophacinone for cont rol of BTPDs within the action area may:

• directly affect listed species by causing mortality or by adversely affecting growth or reproduction through primary exposure to grain bait;

• directly affect listed species by causing mortality or by adversely affecting growth or reproduction through secondary exposure to chlorophacinone poisoned animals, BTPDs or non-target animals, or carcasses.

• indirectly affect listed species and/or modify their designate d critical habitat by reducing or changing the composition of their food suppl y due to a reduction in available BTPDs and non-target animals;

• indirectly affect listed species and/or modify their designate d critical habitat by reducing populations of BTPDs which provide burrows for shelter

59

### 2.9.2. Diagram

The conceptual model is a graphic representation of the structure of the risk assessment. It specifies the chlorophacinone release mechanis ms, biological receptor types, and effects endpoints of potential concern. The conceptual model for all listed species is shown in Figure

2.3 . Although the conceptual models for direct/indirect effects and modification of designated critical habitat PCEs are shown on the same diag ram, the potential for direct/indirect effects and modification of PCEs will be evaluated separately in this assessment. Not included in the risk hypotheses but included in the conceptual diagram is effects to plant communities as a result of reduced or loss of BTPD activity. It is uncerta in whether this alteration to plant community composition would have beneficial and/or detrim ental effects to assessed listed species.

Figure 2.3 Conceptual model depicting stresso rs, exposure pathways, and potential effects to terrestrial organisms from the us e of chlorophacinone on BTPDs.

Stressor

Transport Pathways In Burrow Application

Consumption by BTPDs Incidental Deposition on Surface

via Bioturbation

Exposure

Media

Exposure

Route and Receptors Consumption by non-target terrestrial organisms Exposed Intact Bait at

Application Site

Direct Effect Consumption of Tissues by Predators/Scavengers/

Invertivores

Reduced Reproduction and

Survival of BTPDs and Terrestrial Non-Target Organisms Exposed Intact Bait at

Application Site

Consumption by BTPDs Consumption by non-target terrestrial organisms

Reduced Reproduction and

Survival of BTPDs and Terrestrial Non-Target Organisms

Reduced prey-base for listed species Altered plant community composition Reduced burrows for habitat for listed species 

### Rozol Bait

Indirect

Effect



### 60

### 2.10. Analysis Plan

In order to address the risk hypothe ses, the potential for direct and indirect effects to the assessed species, prey items, and loss of burrows is estimated based on a taxon-level approach. In the following sections, the use, environmental fate , and ecological effects of chlorophacinone are characterized and integrated to assess the risk s. This is accomplishe d using a RQ (ratio of exposure concentration to effects concentration) approach. Although risk is often defined as the likelihood and magnitude of advers e ecological effects, the RQ-based approach does not provide a quantitative estimate of likelihood and/or magn itude of an adverse effect. However, as outlined in the Overview Document (USEPA, 2 004a), the likelihood of effects to individual organisms from the BTPD use of chlorophacinone to control BTPDs is estimated using the probit dose-response slope and either the LOC (discuss ed below) or actual calculated RQ value.

2.10.1. Measures of Exposure

Given the environmental fate properties of chlo rophacinone and its grain-based bait formulation subject to this assessment, only primary exposure to bait and secondary exposure to chlorophacinone poisoned carcasses and invertebra tes will be considered for measures of

exposure.

2.10.1.a. Estimating Primary Exposure

EFED’s exposure assessment for the rodenticides differs from that for most other pesticides. For a rodenticide, the bait itself is the potential food item of concern. Thus, the amount of active ingredient in the formulated bait is used as an EEC. This information is used to estimate the amount of grain bait that birds and mammals of various sizes need to consume to obtain a dose expected to be lethal to 50% of th e individuals in the population (i.e., LD 50 

### dose). Estimates of food-ingestion rates (g dry matter per day) are de termined from established allometric equations presented in EPA’s Wildlife Exposure Factors Handbook (EPA 1993). The concentration of chlorophacinone in grain bait is al so used to estimate initial dietary exposure (mg a.i. per kg in bait) which in turn is used to calculate avian and mammalian dietary RQs.

Acute and chronic LD 50 

### doses are typically used fo r determining EECs; however, a subacute 5-day LD 50 

### will be used in this instance. Du e to chlorophacinone’s delayed mode of action, subacute LD 50 

### values are lower than calculations from acute LD 50 

### endpoints would predict. The acute single-dose LD 50 

### for mammals is 0.49 mg a.i./kg bw/day whereas the subacute 5-day LD 50 

### value is 0.16 mg a.i./kg bw/day. Comp arisons between acute and subacute

data for birds are not as strai ghtforward but the subacute data proves more conservative through

discussions in Section 4.2.1 and calculations performed in Appendix J. Additionally, grain bait applications provide temporary but locally abundant new food s ources. Consequently, exposure over a five day period is highly probable. However, primary expos ure can potentially occur over a longer period of time than five days. Toxicity resulting from chronic exposure exceeding five days cannot be determined based on current data.

61

### 2.10.1.b. Estimating Secondary Exposure

Secondary exposure analysis (from carcass) requires consideration of residues in tissues of target and non-target organisms that are commonly cons umed by predators and scavengers, as well as knowledge of what residue level will result in mort ality or adverse chronic effects. Moreover, it is important to know how long the residue pers ists in body tissues. Registrant submitted BTPD

residue data address these issues , in part, but do not directly de termine residues when BTPDs are most vulnerable to predation and/or scavengi ng. Additionally, carcass handling may not have

allowed a conservative determination of residue concentrations. Residue concentrations for nontarget animals fed chlorophacinone supplement the registrant submitted data. Additionally, a number of laboratory tests using avian and mamma lian predators and scavengers are available to assess mortality from secondary exposure resultin g from consumption of prey animals that had been exposed to chlorophacinone and related an ticoagulant rodenticid es. These studies are

summarized in Table 4.3 and Table 4.4 . Design and methodology vary among studies, adding unknown variability to the result s and analysis. Pending development of standard methods and testing requirements for such studies, these tests provide the best data av ailable. A discussion of residue levels in tissues of target sp ecies is included in the assessment.

2.10.2. Measures of Effect

Data identified in Section 2.8 are used as measures of effect for direct and indirect effects. Data were obtained from registrant submitted studies or from literature studies identified by

ECOTOX.

2.10.2.a. Integration of Exposure and Effects

Risk characterization is the integration of e xposure and ecological effects characterization to determine the potential ecological risk from th e use of chlorophacinone to control BTPDs, and

the likelihood of direct and indir ect effects to the assessed species in terrestrial habitats. The exposure and toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects on non-target species. The RQ method is used to compare exposure and measured toxicity values. EECs are divided by ac ute and chronic toxicity values. The resulting RQs are then compared to the Agency’s LOCs (USEPA, 2004a; Appendix B ).

Data Ga ps 2.10.3.

An avian reproduction study and a te rrestrial field study for the use of chlorophacinone to control BTPDs have been required as conditions of re gistration of Rozol Prairie Dog Bait (7173-286). The registrant submitted a study, “Field Efficacy and Hazards of Rozol Bait for Controlling Black-Tailed Prairie Dogs ( Cynomys ludovicianus )” (MRID 47333602), to support the requirement for a terrestrial field study for BTPDs but the component of the study addressing

field hazards was invalid. The BTPD ch lorophacinone residue study (MRID 47333603) is supplemental but potentially upg radeable after cons ideration of carcass handling methods.

62

### 3. Exposure Assessment

Chlorophacinone, for this assessed use to control BT PDs, is formulated as a grain-bait composed of 50 mg a.i./kg-bait. The a ssessed label (EPA 7173-286) permits in-burrow application of bait in active BTPD colonies only.

3.1. Label Application Rates and Intervals

The label permits hand application of bait in burrows by Certified Applicators or by persons under their direct supervision. One quarter cup of 50 mg a.i./kg-bait (53 grams) is to be placed at

least 6 inches down into ac tive prairie dog burrows. Give n a maximum of 100 prairie dog burrows per acre, this equals an effectiv e maximum application rate of 0.265 g a.i./A 6 

### (King 1959). Any bait scattered on the surf ace or less than 6 inches into the burrow is to be retrieved and disposed.

Fifty-three grams of bait per burrow and 0.265 g a.i. /A will be used to ge nerate RQs in this assessment. It can also be expected that some bait will be exposed above ground from the movement of the target and non-target animals in and out of the burrow (bioturbation). To account for this potential, it will be assumed th at 1% of applied bait will be exposed above ground. This is a conservative estimate consider ing field trials of Rozol Prairie Dog Bait found only one out of 55 samples each containing 50 burrows to have more than 100 grains on the surface (MRID 47333602). Because only one sample out of 55 was found to have more than 100 grains exposed, it is assumed that the number of actual grains is n ear 100 and therefore 100 grains is used. Based on a maximum of 100 burrows per acre (King 1959), this means 200 grains per acre on the surface are possible. Given one grain of bait is 0.2 grams, 0.75% of applied grain will be exposed on the ground surface given this conservative scenario 7 

### . Because the analysis produced an estimate less than 1%, 1% of applied bait on the surface is a conservative assumption.

Following application, the labe l stipulates that the applicator must return to the site initially 5 to 10 days post application to collect and properly dispose of bait or dead or dying prairie dogs and again 14 to 21 days post-application. Carcass collection and burial are to occur in the late afternoon, near sundown, in order to reduce the potential of s cavenging animals finding prairie dog carcasses. Carcasses buried on site must be in holes dug at least 18 inches deep, or in inactive burrows, to avoid scavenging by non-target animals. Burial in cludes covering and packing the hole or burrow with soil.

If prairie dog activity persists “several weeks or months” after the bait wa s initially applied, the label allows a second application by treating burrows in the same manner as the first application.

6 100 burrows/A * 53 g bait/burrow * 0.00005 = 0.265 g a.i./A

7 

### 100 burrows/acre * 53 g/burrow * 1 grai n/0.2 g = 26,500 total grains applied/acre (200 exposed grains)/( 26,500 to tal grains applied/acre) = 0.75 % grains exposed

63

### 3.2. Aquatic Exposure Assessment

3.2.1. Aquatic Exposure in Previous Assessment

A previous assessment (EPA 2008) modeled aqua tic exposure of chlorophacinone for this use and found that negligible concen trations of chlorophacinone coul d occur in the water column relative to the toxicity to aquatic organisms. Model results indicated a peak concentration of 0.92 parts per trillion in surface wate rs for this use. This result is driven by chlorophacinone’s immobility within its grain bait formulation. The most sensitive aquatic endpoint is an LC 50 

### of 450 parts per billion fo r the rainbow trout ( Oncorhynchus mykiss ). This endpoint is more than five orders of magnitude greater than the EEC. Gi ven this, risk to aquatic listed species and risk to aquatic habitats and PCEs of designated critical habitats will not be further assessed.

3.3. Terrestrial Exposure Assessment

Pesticide residues, other than those in poisoned animals and carcasses, are not of environmental concern because the active ingredient is not mobile and will remain sorbed to the grain bait. The RQ method of assessment is used to make risk determinations. The RQ method is preferred because it is quantitative, thus providing concrete justification for risk de terminations. However, this method is supplemented by data gathered from chlorophacinone-poisoned carcass feeding

studies.

3.3.1. Ingestion Rate Determination

RQs are generated by dividing daily dietary exposure of chlor ophacinone for a given species by the most conservative toxicity endpoint for the relevant taxa ad justed for body weight of the given species. Dietary exposur e estimates were derived usin g allometric equations from Wildlife Exposure Factors Handbook (EPA 1993). Allometric equations are distinct by taxon and can be refined within a taxon as well. For the purposes of this assessment, generic taxon allometric equations will be used. The following equations require input of animal weight (Wt) and produce an estimate of daily food intake (FI).

FI (g/day) = 0.648 * Wt 0.651 

### all birds FI (g/day) = 0.235 * Wt 0.822 

### all mammals

The animal weight input is dete rmined using the lowest relevant 8 

### weight for juveniles and adults of a given listed species. For species that do not exceed the LOC based on this determination, a weight range sensitivity analysis will be performed to account for lower metabolic rates of larger animals. Refinements can also be made, as needed, for RQs approaching the LOC based on other relevant allometric equations within the Wildlife Exposure Factors Handbook . These refinements will be made only if the outcome wo uld change a MA determination from NLAA to

LAA.

8 An animal weight is only relevant if it can be expected that exposure to chlorophacinone will occur at the given life

stage.



### 64

### 3.3.2. Food Intake Assumptions Re levant to Terrestrial Exposure

For the calculation of RQs, it is assumed the exposed animal consumes chlorophacinone bait or chlorophacinone poisoned animals and/or carcasse s, depending upon the species diet, exclusively for the relevant period of exposure. For assessment of taxa with 5-day LD 50 

### or LC 50 

### values, it is assumed that the exposed animal consumes chlorophacinone bait or chlorophacinone poisoned animals and/or carcasses exclusively for five consecutive days. Th e subacute (5-day) LD 50 

### s and

LC 50 

### s are both discussed on a single day exposure basis because RQs are calculated based on single day ingestion rates.

3.3.2.a. Chlorophacinone Concentrations in Food Items

The proportion of chlorophacinone in Rozol bait is 50 mg a.i./kg-bait. Assuming exclusive consumption of bait, listed species are expos ed to chlorophacinone at the following rate:

Chlorophacinone intake (mg/time) = 0.05 mg/g * FI (g/time)

All inputs for determining the chlorophacinone do se-based EEC are presented in the following tables. Only dose-based EECs for mammals ar e used for calculating RQs. Avian RQs are

calculated from an LC 50 

### which is dose independent and more conservative than avian LD 50 

### data. Appendix J demonstrates this through the calculation of avian RQs using LD 50 

### data.

Table 3.1 Calculation of chlorophacinone in take for birds and herptiles using most conservative secondary exposure scenario. Calculations based on FI (g/day) = 0.648 * Wt (dry) 0.651 

### (EPA 1993); ingestion rate in terms of wet weight is calculated using the following equation: Ingestion Rate (wet weight) (invertivores) = Ingestion Ra te (dry weight)/(1-0.84) (EPA 1993) Ingestion Rate (wet weight ) (carnivores) = Ingestion Rate (dry weight)/(1-0.68) (EPA 1993) Dose-based EEC = (Residue*FI)/(Wt/1000)

Species Weight (Wt)(g) Food Ingestion (FI) (g [ww]/day) Residue (mg/kg-diet [ww]) 1 

### Dose-based EEC (mg/kg-bw/day)

California condor (carnivore) 8,100 709.33 5.8 0.508

Whooping crane (carnivore) 4,300 150.30 2 

### 50 1.748 Eskimo curlew (invertivore) 270 155.0 5.8 3.329 Northern Aplomado falcon 410 101.71 5.8 1.439 Chirichaua leopard frog (invertivore) 100 81.18 5.8 4.709

Mexican spotted owl (carnivore) 519 118.58 5.8 1.325

Piping plover (invertivore) 42 46.15 5.8 6.373 New Mexican ridge-nosed rattlesnake (carnivore) 85 36.52 5.8 2.492

Sonora tiger salamander (invertivore) 50 51.70 5.8 5.997

65

### Black-capped vireo (invertivore) 9 16.93 5.8 10.91

Golden-cheeked warbler (invertivore) 10 18.13 5.8 10.52

1 The residues for birds and herptiles are either 50 for bait or 5.8 for non-target animals. The residues in mice were used as a surrogate for invertebrate residues.

2 This value was not converted to wet weight because the value is for bait which is in dry weight.



### Table 3.2 Calculation of chlorophacinone in take for mammals usin g most conservative secondary exposure scenario. Calculations based on FI (g/day) = 0.235 * Wt 0.822 

### (EPA 1993); ingestion rate in terms of wet weight is calculated using the following equation: Ingestion Rate (wet weight) = Ingestion Rate (dry wei ght)/(1-0.68) (EPA 1993) ; Dose-based EEC = (Residue*FI)/(Wt/1000)
Species Weight (Wt) (g) Food Ingestion (FI) (g [ww]/day) Residue (mg/kg-diet [ww]) 1 

### Dose-based EEC (mg/kg-bw/day)
Grizzly bear 102,000 3077.07 2 

### 50 1.508

Black-footed ferret 635 147.84 5.8 1.350 Jaguar 36,363 4118.89 5.8 0.657 Gulf Coast jaguarundi 4,500 739.36 5.8 0.953 Canada lynx 5,100 819.48 5.8 0.932

Preble’s meadow jumping mouse 13 1.94 2 

### 50 7.443

Ocelot 11,300 1575.97 5.8 0.809 Gray wolf 18,000 2310.74 5.8 0.745

1 The highest residue concentration (either bait [50 mg a.i./k g-bait] or non-target animals [5.8 mg a.i./kg-bw]) was

used.

2 These values were not converted to wet weight because the value is for bait which is in dry weight.



### The determination of chlorophacinone intake for listed species c onsuming chlorophacinone poisoned animals or carcasses is calculated sim ilarly but relies on carcass residue data. BTPD

carcass residue data is derived fr om a registrant sponsored study performed by the United States Department of Agriculture National Wildlif e Research Center (MRID 47333603). This study

was reviewed and determined to be used as s upplemental. This decision was made because the study did not describe carcass hand ling methods. However, the study can be used quantitatively. The mean whole body average corrected wet weight concentration of chlo rophacinone for prairie dogs fed Rozol to mortality is 1.03 mg a.i./k g-bw with a maximum concentration of 2.24 mg a.i./kg-bw in a single carcass. To be protective and to account for the supplemental nature of the data, a residue concentration of 2.24 mg a.i. /kg-bw will be used to assess exposure to chlorophacinone poisoned prairie dogs and prairie dog carcasses. Assuming exclusive consumption of chlorophacinone poisoned prairie dogs and prairie dog carcasses, listed species are exposed to chlorophacinone at the following rate:

Chlorophacinone intake (mg/time) = 0.00224 mg/g * FI (g/time)

66

### Other granivores aside from BTPDs ( i.e. mice, rabbits, birds, invertebrates etc. ) have the potential to consume chlorophacinone bait. These non-target granivores al so have the potential for different mean and maximum chlorophacinone re sidue concentrations than those determined for BTPDs. To characterize these differences, carcass residue concentr ation data from open literature was considered (see Table 3.3 ). Because formulation concentration can affect carcass residue concentration, only studi es using bait with chlorophaci one concentrations of 50 mg a.i./kg-bait were considered. Re sidue concentrations resulting fr om other bait formulations are also presented in Table 3.3 for context. Th e highest whole-carcass residue concentration reported matching this criterion is 5.8 mg a.i./kg-bw for labor atory mice (Anonymous, 1981). It

is uncertain whether this residue concentration is presented in wet weight or dry weight. For the purposes of this assessment, it is assumed that 5.8 mg a.i./kg-bw re presents a wet weight concentration. For secondary e xposure RQs approaching the listed species LOC and for animals likely to prey upon non-target species, this resi due concentration can be used to address predation and scavenging of non-target primary consumers. Further, food ingestion rates do not necessarily reflect actual ingest ion patterns as predators and scav engers may engorge themselves prior to and following hibernation and during migration. In addition, some species (e.g., California condor) may not eat every day.

Residue concentrations in invertebrates that may be preyed upon by invertivores are not as well

characterized as residue concen trations in mammals that may be preyed upon by carnivores. However, secondary exposure to anticoagulant ex posed invertebrates has been attributed to the poisoning of birds. Godfrey (1985) cited an incident at an avia ry where several birds (avocets, pitas, plovers, finches, thrushes, warblers, crak es, honey creepers) died after being exposed to

brodifacoum. Brodifacoum concentrations of 0.081 to 1.69 mg a.i./kg-bw were reported in tissues of dead birds. Because bait was applied in bait stations, it was assumed that the birds were exposed by feeding on pavement ants and cockroaches that had eaten bait. One study evaluating diphacinone residues in slugs exposed to grain bait similar to Rozol found maximum wet weight residue concentrations of 4.0 mg a.i./kg-bw (Primus et al. 2006). Because the body

of literature is limited and availa ble maximum invertebrate residue concentrations are lower than

better characterized mammal residue concentrati ons, the 5.8 mg a.i./kg-bw residue value for mice will be used as a surrogate value for invertebrate residue exposure. This surrogate value

will result in a more conservative assessment.

Table 3.3 Chlorophacinone Residue Levels in Primary Consumers

mg ai/kg

bait Target species Site Sample

size Days exposed Whole-carcass residue (mg a.i./kg-bw) Reference

100 ground squirrel field 10 unknown 1.27 + 0.56 (sd) Baroch 1996b

75 b mouse laboratory ? 3 6.0 Riedel et al. 1991 a

50 ground squirrel field 10 unknown 0.57 + 0.27 (sd) Baroch 1996a

50 ground squirrel field 10 unknown 0.52 + 0.31(sd) Baroch 1996b

50 rat laboratory 5 5 0.47 (0.21-0.93) Baroch 1997



### 67mg ai/kg

bait Target species Site Sample

size Days exposed Whole-carcass residue (mg a.i./kg-bw) Reference

50 rat laboratory 4 5 0.45 (0.18-0.81) Ahmed et al. 1996

50 vole laboratory 10 < 9 3.2 Askham and Poché 1992

50 or

100 c ground squirrel field 62 unknown 0.264 Primus et al. 2001

50 or

100 c vole field 3 unknown 1.58 (0.26-4.1) Primus et al. 2001

50 mouse laboratory ? 3 5.8 Anonymous 1981 a

50 or

100 c pocket gopher field 8 unknown 0.518 Primus et al. 2001

50

and

100 d ground squirrel field 53 unknown 0.93 Goodall et al. 2002

a cited in Joermann 1998

b chlorophacinone baits registered in the U. S. are either 0.005% or 0.01% ai

c carcasses were collected in the field in CA, where both 50 mg a.i./kg-bait and 100 mg a.i./kg-bw chlorophacinone baits are registered

d the study did not distinguish between ground squirrels exposed to 50 mg a.i./kg-bait and 100 mg a.i./kg-bait baits



### 3.3.2.b. Adjusting for Snake Food Intake

Though avian toxicity data are used as a surroga te for assessing toxicity to snakes, dietary exposure is distinct and is asse ssed using methods that reflect snake feeding habits. Avian food intake equations may underestimate exposure to sn akes when birds are used as a surrogate and are assumed to eat similar dietary items because of the large meal size a snake may consume on a single day. This equation is m odified to estimate exposure to snakes based on the maximum size prey item they could consume and is used to re fine a risk estimate. The following allometric equation developed by King (2002) was used to estimate the maximum size prey items for

snakes.

)g(Mass Snake (g) SizePrey 1.015



### =

The 95% confidence limits on th e coefficient are 0.959 and 1.071 (King, 2002). The upper limit is used to estimate exposure to snakes ( i.e. . 1.071 )

.

4. Effects Assessment

This assessment evaluates the potential for chlo rophacinone formulated as Rozol Prairie Dog Bait (EPA registration number 7173-286) to directly or indirectly a ffect listed species or modify their designated critical habitat. Assessmen t endpoints for the effects determination for each

68

### assessed species include direct to xic effects on the survival, repr oduction, and growth, as well as indirect effects, including reducti on of the prey base or modificati on of its habitat. In addition, potential modification of critical habitat is assessed by evaluating effects to the PCEs, which are components of the critical habitat areas that pr ovide essential life cycl e needs of each assessed species.

As described in the Agency’s Overview Docume nt (USEPA, 2004a), the most sensitive endpoint

for each taxon is used for risk estimation. For this assessment evaluated taxa include birds,

mammals and terrestrial invertebrates. Birds are used as the surrogate taxa to assess for herptiles. Acute (short-term) toxicity inform ation is characterized based on registrant-submitted studies and a comprehensive review of the open literature on chlorophacinone. Chronic toxicity

information is not available and has not been re quested for mammals because mortality occurs at low doses in acute tests. Chronic toxicity info rmation is not available for birds either but an avian reproduction study has been requested. There is more potential for chronic effects to birds because mortality occurs at doses high enough to allow for longer term exposures. In the absence of an avian reproduction study, effects to birds and herptiles cannot be precluded.

4.1. Ecotoxicity Study Data Sources

Toxicity endpoints are established based on data generated from guideline studies submitted by the registrant and from open literature studies that meet the criteria for inclusion into the ECOTOX database maintained by EPA/Office of Research and Development (ORD) (USEPA, 2004a). Open literature data pr esented in this assessment were obtained from the Comparative Assessment (USEPA, 2004b), as well as ECOT OX information obtained on May 14, 2010. In

order to be included in the ECOTOX databa se, papers must meet the following minimum

criteria:

1. toxic effects are related to single chemical exposure;

2. toxic effects are on an aquatic or terrestrial plant or animal species;

3. a biological effect is identif ied on live, whole organisms;

4. a concurrent environmental chemical concentr ation/dose or applicati on rate is reported;

and

5. the duration of exposure is explicit.

Data that pass the ECOTOX screen are evaluate d along with the registrant-submitted data, and may be incorporated qualitatively or quantitatively into this enda ngered species assessment. In general, effects data in the open literature th at are more conservative than the registrantsubmitted data are considered. The degree to wh ich open literature data are quantitatively or qualitatively characterized for th e effects determination is depe ndent on whether the information is relevant to the assessment endpoints ( i.e. , survival, reproduction, a nd growth) identified in

Section 2.8 . For example, endpoints such as behavior m odifications are likely to be qualitatively evaluated, because quantitative relationships betw een behavior modifications and reduction in species survival, reproduction, and/or growth are not availa ble. Although the effects determination relies on endpoints that are releva nt to the assessment endpoints of survival, growth, or reproduction, it is important to not e that the full suite of sublethal endpoints

69

### potentially available in the effects literature (r egardless of their significance to the assessment endpoints) are considered, as they are relevant to the understanding of potential effects, as defined for the action area. Sublethal lethal endp oints of internal bleeding and hemorrhaging are considered equivalent to lethality in the c onsideration of avian secondary exposure data.

Citations of all open literature not considered as part of this assessment b ecause they were either rejected by the ECOTOX screen or accepted by ECOTOX but not used ( e.g ., the endpoint is less sensitive) are included in Appendix F. Appendix F also includes a rationale for rejection of those studies that did not pass th e ECOTOX screen and those that were not evaluated as part of this endangered species risk assessment.

A detailed spreadsheet of the available ECOTOX open literature data, including the full suite of lethal and sublethal endp oints is presented in Appendix G

.

In addition to registrant-submitted and open litera ture toxicity information, other sources of information, including use of the acute prob it dose response relationship to establish the probability of an individual effect and reviews of ecological incident data, are considered to

further refine the characterizati on of potential ecological effect s associated with exposure to chlorophacinone. A summary of the available terrest rial ecotoxicity information and the incident information for chlorophacinone are provided in Sections 4.2 through 4.3

.

4.2. Toxicity of Chlorophacinone to Terrestrial Organisms

A brief summary of registrant-submitted and open literature data considered relevant to this ecological risk assessment is presented in Appendix E . Studies submitted during the comment period relevant to “Receipt of Petition Reques ting EPA to Suspend the Registration of Rozol Prairie Dog Bait and Cancel Certain App lication Sites” (EPA -HQ-OPP-2009-0684) are

discussed in Appendix D. All endpoints are expressed in te rms of the active ingredient unless otherwise specified.

Table 4.1 summarizes the most sensitive terrestrial toxi city endpoints, based on an evaluation of both the registrant-submitted studies and the open lit erature, as previously discussed. When data are available, it was found that the most conservative 5-day LD 50 

### value is more protective than the most conservative single dose LD 50 

### value.

Table 4.1. Toxicity Profile for Chlorophacinone

Assessment Endpoint Acute/

Chronic Species Tested Toxicity Value Used

in Risk Assessment Citation or

MRID Comment

Acute Northern bobwhite Colinus virginianus LD 50 = 258 mg a.i./kg

bw Slope = 2.88 41513101 Bird

Toxicity to listed species 5-day

Sub-Acute Northern bobwhite Colinus virginianus LC 50 = 56 mg a.i./kgdiet Slope = 1.49 41513102

Mammal Acute Deer mouse Peromyscus LD 50 = 0.49 mg a.i./kgbw Clark 1994



### 70Assessment Endpoint Acute/

Chronic Species Tested Toxicity Value Used

in Risk Assessment Citation or Comment

MRID

maniculatus Toxicity to listed species 5-day

Sub-Acute Norway Rat Rattus norvegicus 5-day LD 50 = 0.8 mg a.i./kg-bw Jackson and

Ashton 1992 Doses of 0.16 mg a.i./kg bw were administered daily for 5 consecutive days equal the

LD 50 dose

Terrestrial

Invertebrate

Toxicity to listed species Chronic Burying beetle Nicrophorus

orbicollis Carcasses fed 50 mg a.i./kg-bait for 5-10 days affected number of beetles emerged 47383001 This study was classified as supplemental.



### 4.2.1. Toxici ty to Birds

Chlorophacinone is moderately toxic to birds with the most sensitive endpoints being an acute

LD 50 

### of 258 mg a.i./kg bw and a 5-day sub-acute LC 50 

### of 56 mg a.i./kg-diet. Birds are more sensitive to sub-acute exposure th an single-dose acute exposure.

An avian reproduction study for chlorophacinone has been required but has yet to be submitted. In the absence of this study a nd any open literature st udy that may supplement it, risk of adverse

effects to avian and herptile reproduction canno t be precluded.

4.2.1.a. Sublethal Effects and Additional Open Literature

Information

The effects of chlorophacinone poisoned carcasses on predatory a nd scavenging birds have been evaluated in many studies. This informati on was previously compiled (USEPA, 2004b) (see

Table 4.2 ). The current ECOTOX bibliography ( updated May 2010) does not indicate any new

studies relevant to the effects of chlorophacinone poisoned animal s and/or carcasses on predatory and scavenging birds. Though no mortalities were reported in these studi es, sublethal effects including external bleeding, in ternal hemorrhaging and increa sed blood coagulation time were

noted. Previous assessments have considered these effects to be analogous to lethality. Though these studies do not allow for quantification of e ffect, they confirm that secondary exposure can

result in effect.

Table 4.2 Secondary Hazards of Chlorophacinone to Birds in Laboratory Studies

Predator/

scavenger (p/s) Prey offered to p/s No. prey

offered daily per p/s No. days p/s exposed No. p/s exposed No. p/s

dead No.

survivors with signs

of chlorophaci

none toxicity a Reference

Barn owl rats fed choice of 0.005%

bait or untreated bait for 5 days 1-2 10 2 0 0 Mendenhall

and Pank

1980



### 71Predator/

scavenger (p/s) Prey offered to p/s No. prey

offered daily per p/s No. days p/s exposed No. p/s exposed No. p/s

dead No.

survivors with signs

of chlorophaci

none toxicity a Reference

Black-billed magpie rats fed 0.005% bait for 5 days ad lib. 5 20 0 0 Baroch

1997

American

kestrel voles fed 0.01% bait until

dead 1 1 every 3 days 21

61 10

10 0

0 10 (eb/ih) 10 (eb/ih) Radvanyi et

al. 1988

Red-tailed

hawk voles fed 10 g 0.005% bait daily for up to 9 days 2 6 5 0 0 Askham and

Poché 1992

Great

horned owl voles fed 10 g 0.005% bait daily for up to 9 days 2 6 1 0 0 Askham and

Poché 1992

Red-tailed

hawk voles fed 0.005% bait for

up to 9 days 2 6 5 0 0 Askham

1988

Great

horned owl voles fed 0.005% bait for

up to 9 days 2 6 1 0 0 Askham

1988

Tawny owl mice fed 0.0075% bait b ad lib. 10 4 0 (ct) Riedel et al.

1991 c

Eurasian

buzzard mice fed 0.0075% bait b ad lib. 7

10

5+5+5 d

40 4

6

3

3 0

0

0

0 (ct) (ct) (ct) (ct) Riedel et al.

1991 c

Eurasian

buzzard mice fed 0.0075% bait b 4 7 4 0 0 Anonymous

1978 c

Carrion

crow mice fed 0.0075% bait b ad lib. 10 4 0 (ct) Riedel et al.

1991 c

Carrion

crow mice fed 0.0075% bait b 3-4 3

5 12

12 0

0 0

0 Sterner

1978 c

White stork mice fed 0.0075% bait b ad lib. (treated

/untreated ) 3

14 3

3 0

0 1 or 2 (ct) 1 or 2 (ct) Sterner

1981 c

a eb = external bleeding; ih = internal hematoma; bl = blee ding (unspecified); ct = incr eased blood coagulation time; nr = not reported

b baits registered in the U.S. are either 0.005% or 0.01% ai

c cited in Joermann 1998

d the 3 5-day treatment periods are separated by 3 days when the birds were fed untreated mice



### 72

### Based on the information in Table 4.2 , the observed sublethal eff ects (e.g., external bleeding, internal hematoma, and increased blood coagulation time) occurred at levels close to but above

the % a.i. used for BTPD control. Subletha l effects were seen for 0.0075 and 0.01% a.i. bait

whereas the bait used for BTPD control is 0.005%.

4.2.2. Toxicity to Mammals

Chlorophacinone is very highly toxic to mammals with the most sensitive endpoints being an

acute LD 50 

### of 0.49 mg a.i./kg bw and a 5-day LD 50 

### of 0.8 mg a.i./kg bw (0.16 mg a.i./kg bw dose daily for five days). Mammals are most sens itive to sub-acute exposure due to the chemical’s mode of action. A given mammal would n eed one-third of the single day acute LD 50 

### dose each day for five days to achieve a 5-day subacute LD 50 

### dose. A five day exposure is reasonable considering the bait application is intended to provide multiple exposures to individual BTPDs.

4.2.2.a. Sublethal Effects and Additional Open Literature

Information

The effects of feeding chlorophacinone poi soned carcasses to predatory and scavenging mammals have been evaluated in many studies . This information was compiled (USEPA, 2004b) (see Table 4.3 ). The current ECOTOX bibli ography (updated May 2010) does not indicate any new studies relevant to the effects of feeding chlo rophacinone poisoned carcasses to predatory and scavenging mammals. Of 55 mammals tested, 32 died before the end of the study period. Considering these studies as a whole, secondary exposure of chlorophacinone to mammals consistently causes a le thal effect. Sublethal effect s of bleeding and increased blood coagulation time were also reported. Previous as sessments have considered these effects to be analogous to lethality. Though th ese studies do not allow for qua ntification of effect, they confirm that secondary e xposure results in effect

Table 4.3 Secondary Hazards of Chlorophacinone to Mammals in Laboratory Studies

Predator/

scavenger (p/s) Prey offered to p/s No. prey

offered daily per p/s No. days p/s exposed No. p/s exposed No. p/s

dead No. survivors with signs of chlorophacin one toxicity a Reference

Mongoose rats fed 0.005% bait for 5 days 1 1

3

5

6

7

9

10 1

1

2

1

1

1

1 0

1

2

1

1

1

1 nr no survivors

no survivors

no survivors

no survivors

no survivors

no survivors Pank and

Hirata 1976

Coyote ground squirrels fed 15 g of

0.01% bait for 6 days b 1 5 7 3 0 Marsh and

Howard 1986



### 73Predator/

scavenger (p/s) Prey offered to p/s No. prey

offered daily per p/s No. days p/s exposed No. p/s exposed No. p/s

dead No. survivors with signs of chlorophacin one toxicity a Reference

Red fox mice fed

0.0075% bait c 20 total 4 1 1 d no survivors Bachhuber

and Beck

1988 e

European

ferret rats fed 0.005% bait for 5 days ad lib. 5 20 11 nr Ahmed et al.

1996

European

ferret prairie dogs fed 25 g of 0.0025% bait daily for 6 days c 4 (1 every other day) 8 6 5 nr Fisher and

Timm 1987

European

ferret voles/mice fed

0.0075% bait c 5 total 4 2 1 f (ct) Bachhuber

and Beck

1988 e

European

ferret muskrats fed

0.005% bait ad lib. 4

8 2

1 0

1 1 (bl)

no survivors Jobsen 1978 e

European

ferret voles fed

0.0075% bait c ad lib. 3 4 0 (ct) Anonymous

1983 e

Weasel mice fed 0.005%

bait ad lib. 90 4 3 0 Anonymous

1981 e

a eb = external bleeding; ih = internal hematoma; bl = blee ding (unspecified); ct = incr eased blood coagulation time; nr = not reported

b ground squirrels were fed no-choice for 3 days followed by 3 days in which they had a choice of bait or untreated laboratory chow

c baits registered in the U.S. are either 0.005% or 0.01% ai

d individual was sacrificed but considered ‘dead’ based on coagulation index



### 4.2.3. Toxicity to Terrestrial Invertebrates

The endangered American burying beetle ( Nicrophorus americanus ), uses mammalian and avian carcasses as food resource during their reprodu ction cycle. A study on a related, abundant congeneric species, Nicrophorus orbicollis , was performed to assess the impacts of chlorophacinone on the survival and larval gr owth of burying beetles (MRID 47383001). There were two phases to this study. The first phase investigated effects of chlorophacinone on the emergence (number of beetles produced), growth , and sex ratio of burying beetles raised on chlorophacinone-dosed rat carcasses. The second phase of the study investigated effects on the survival and reproductive success of burying beetle adults fed chlorophacinone-dosed meat for 28 days prior to being provided an u ndosed quail carcass for brooding of young.

74

### In the first phase of the study each of twenty reproductively mature male-female pairs of fieldcollected N. orbicollis was offered a chlorophacinone-dosed ra t carcass. Each of an additional twenty reproductively mature male-female pairs wa s offered an undosed rat carcass as a control. In the wild a carcass is usually buried in less than a day, and the female oviposits eggs in the surrounding soil within about 48 hours (Wilson and Knollenberg, 1984). Upon emergence of offspring (approximately one month later), the total number of young produced per brood was counted, sexed, and weighed. The chlorophacinone -dosed carcasses were a group of 20 rats fed exclusively 50 mg a.i./kg chlorophacinone bait for a period of 5 to 10 days until death. This is

same bait concentration which would be used in the environment. A group of 20 undosed rats

which were fed a standard laborator y rodent diet were used as c ontrols. Upon death all rats were frozen and shipped to the study location wher e they were thawed for 24 hours prior to use. While it was indicated in the study th at the control rats were select ed to be of similar body size as the treatment group, reported control carcass weights (mean 102.8 grams) used in the study were significantly greater (P<0.001) than those used in the chlorophacinone treatment group (mean 89.6 grams). No conclusions about the difference in carcass body weights being

attributable to the chlo rophacinone-bait diet should be drawn from this aspect of the study; rats during the pretest period were not from a paired study designed to evaluate effects to rats.

Number of emerged beetles, the male-female rati o, and individual beetle and total brood weights of treatment and control broods were compared using nonpaired t-tests. Significantly (P<0.01) fewer beetles emerged from the chlorophacinone- dosed carcasses (mean 12.7 beetles) than from control carcasses (mean 22.5 beetles). There was so me conjecture that this difference might be attributable to the difference in carcass weight rather than the presence of chlorophacinone. However, an evaluation of the relationship between brood size and carcass weight in the open

literature indicates that both the control and chlorophacinone carcass weights are outside the range that limits brood size and therefore the reduc tion observed is attribut ed to chlorophacinone. A significant positive relationship between reproductive success a nd increasing carcass size has been observed in the range of 7 to 35 grams (Wilson and Fudge, 1984; Trumbo, 1990; Trumbo and Fernandez, 1995; Creighton, 2005) , average brood size in the rat- carcass controls from this chlorophacinone study (mean 22.5 beetles) was on pa r with brood size observed in the upper size range of this relationship (average of 14.4 – 22 b eetles at 30 – 35 g). A similar pattern has been observed with a different burying beetle species wherein at smaller carcass sizes a positive relationship between brood size a nd carcass size were observed but above a given size no further gain occurred. Additionally, it has been conjectu red that above a given carcass size brood size for a single pair of beetles might be reduced due to cost of maintenance, or lack of ability to maintain the carcass. Total biomass, which is not independent of brood size, was also found to be significantly reduced (P<0.01) on chlor ophacinone-dosed carcasses. But growth of individuals (total biomass adju sted for brood size) in chlor ophacinone-dosed carcasses was not significantly different from cont rol weights (P=0.25). Additi onally no effect was observed on the male-female ratio. Thus, this phase of the study showed that chlorophacinone-dosed

carcasses have effects on larval survival at c oncentrations relevant to this assessment.

The second phase of the study inve stigated effects on the surviv al and reproductive success of burying beetle adults fed chlor ophacinone-dosed meat for 28 days prior to being provided an undosed quail carcass for brooding of young. A preliminary study conducted by the National Wildlife Research Center found that chloropha cinone residues in whole body prairie dog

75

### 76 carcasses ranged from 0.85 mg a. i./kg-bw to 2.25 mg a.i./kg-bw. Based on this information, laboratory raised adult N. orbicollis beetles were provided a no-choi ce test diet consisting of 3.0 ppm chlorophacinone in ground beef, which exceeded the high end of this range, for 28 days. Control adult beetles were fed undosed ground beef . Beetles were segregated by gender during this feeding period.

After the feeding period, surviving male-female pa ired beetles were offered a thawed non-dosed Japanese quail carcass. Upon emergence of offs pring (approximately one month later), the total number of young produced per brood were count ed, sexed, and weighed. Number of emerged beetles, male-female ratio, and individual beetle and total brood weights of the treatment and control broods were compared using nonpaired t- tests. During the 28 day no-choice feeding trial, 12.5% of control adults died compared to 4.7% mortality of adults in the treatment group. It appears from these results that chlorophacinon e has no direct negative impact on survival of adult beetles. No significant differences were found between treatment and control groups in the test for evaluating the subsequent ability of adults fed no-choice diets to brood and produce normal progeny. The following variables were ev aluated: quail carcass weight (in grams), number of beetles produced/brood, number of beetles/carcass we ight, weight/beetle, estimated total brood weight/brood, brood weight/carcass weight, number of females/brood, number of males/brood, male-female ratio/brood, and pr oportion of males/brood. The study authors believed that the lower number of broods produced in this experiment, relative to the first which used rat carcasses, may be due to either the age of the beetles and/or the use of a different type/condition of carcass.

The results of the study performed on N. orbicollis to assess the impacts of chlorophacinone on burying beetles showed that adult burying beetle survival and fecundity is not affected at environmentally relevant residue levels but that larvae brood ing on chlorophacinone residues have reduced survival (MRID 47383001). Therefore, it is expected that a ny insect with exposure to chlorophacinone residues dur ing its developmental early lif e stage will have significant effects. This effect is considered a reproductive effect. However, no other effects to insects are expected since chlorophacinone expo sure to adults resulted in mo re of the control beetles dying when compared with those in the treatment group who were fed a no-choice diet of chlorophacinone dosed ground beef. Furthermore, once these adults, both the control group fed non-dosed ground beef and the treatment group fed chlorophacinone dosed ground beef, were offered non-dosed quail carcasses no significant effects were s een in the treatment group.

A 14-day toxicity test on the earthworm ( Eisenia foetida ) found a LOAEL at soil concentrations of 556 mg a.i./kg-soil chlorophacinone (MRID 47383002) . This concentration is more than ten

times the concentration of Rozol Pr airie Dog Bait (50 mg a.i./kg-bait) . It is outside the realm of possibility that concentrati ons approaching the LOAEL conc entration will occur in the environment. Additionally, an open literatu re study in which th e Wellington tree weta ( Hemideina crassidens ) was exposed to and consumed di phacinone bait for up to 64 days found no effect (Fisher et al. 2007). Diphacinone shares the same mode of action as chlorophacinone and is very similar in chemical structure. Based on these studies and the study described above, only reproductive effects to terrestrial invertebrates are expected to occur.77Table 4.4 Evaluation of the Terrestrial Invertebrate Reproduction Study.StudyDescriptionA.I.ConcentrationStudy parametersTest ResultsMRIDClassificationCategoryPhase 1:Poisonedcarcasses fed toburying beetles(Nicrophorusorbicollis)Rats fedexclusively 50 mga.i./kgchlorophacinonebait for a period of5-10 days untildeath resulting inunknown residueconcentrations.Each of 20 female-male pairs of fieldcollectedN. orbicolliswas offered achlorophacinone-dosed rat carcassand each of another 20 female-malepairs was offered a non-dosed ratcarcass. Upon emergence ofoffspring the total number of youngproduced per brood was counted,sexed, and weighed. Numbers,male-female ratio, and individualbeetle and total brood weights oftreatment and control broods werecompared.Significant differences between control and treatmentgroups were found for the following endpoints: carcassweight, number of beetles produced, estimated total broodweight (g). Based on open literature the differences incarcass weight between the control and treatment groupsare not expected to have influenced study results. Totalbrood weight is not independent of number of beetlesproduced, and analysis of individual beetle weight showsno significant effect on growth. There was no significanteffect on the male-female ratio.Therefore, the main effectwas larval survival.473830-01Supplemental/non-guidelinePhase 2: Dosedground meatfeed for 28 daysto buryingbeetles(N. orbicollis)followed bybrooding ofyoung on aclean carcassAdultN. orbicolliswere fedchlorophacinonedosed (3.0 ppmchlorophacinone)ground beef.64 adult laboratory rearedN.orbicollis(36 females/28 males)were fed a no-choice diet ofchlorophacinone-dosed (3.0 ppmchlorophacinone) ground beef.Another 64 adultN. orbicollis(36females/28 males) were fed a nochoice diet of non-dosed groundbeef. After the feeding trial,surviving adult male-female pairswere offered a thawed non-dosedJapanese quail carcass. Uponemergence of offspring the totalnumber of young produced per broodwas counted, sexed, and weighed.Numbers, male-female ratio, andindividual/total brood weights of thetreatment and control broods werecompared.During the 28 day no-choice feeding trial, 12.5% of thecontrol adults died compared to the 4.7% mortality of theadults in the treatment group, demonstratingchlorophacinone has no directnegative impact on survivalof adult beetles. No significant differences were foundbetween the treatment and control groups in the second partof the second phase of the study (subsequent ability ofadults fed no-choice diets to brood and produce normalprogeny). The following variables were evaluated: quailcarcass weight (in grams), number of beetlesproduced/brood, number of beetles/carcass weight,weight/beetle, estimated total brood weight/brood, broodweight/carcass weight, number of females/brood, numberof males/brood, male-female ratio/brood, and proportion ofmales/brood. The study states that the authors believed thatthe lower number of broods produced in this experiment,relative to the first which used rat carcasses, may be due toeither the age of the beetles and/or the use of a differenttype/condition of carcass.473830-01Supplemental/non-guideline

### 4.3. Incident Database Review

A review of the Ecological Incident Informa tion System (EIIS, version 2.1), the ‘Aggregate Incident Reports’ (v. 1.0) data base, and the Avian Monitoring Information System (AIMS) for ecological incidents involving chlorophacinone wa s completed on June 14, 2010. The results of this review for terrestrial, plant, and aquatic incidents are discussed below in Section 4.3.1 . A complete list of the incidents involving chlor ophacinone including associat ed uncertainties is

included as Appendix I

.

4.3.1. Terrestrial Incidents

Nine incidents, involving 87 ma mmals and birds, have been re ported that can be reasonably attributed to chlorophacinone poiso ning as the primary cause of death. Four of these incidents, involving five mammals and birds, can be attr ibuted to use of chlorophacinone to control

BTPDs. The incidents can be found unde r the reports: I0206 07-001, I019311-001, I012972-001 and FWS 2007600155R003. The five animals included two badgers, two turkeys, and a bald eagle. Liver concentrations for these incidents ra nge from 0.30 mg a.i./kg-bw for the bald eagle to 4.4 mg a.i./kg-bw for one of the badgers. Fo r all five animals, the primary indication of anticoagulant poisoning ( i.e., internal hemorrhaging) was reported.

One additional incident (FWS 2009600498), involv ing a ferruginous hawk and a great horned owl, is not attributed to chlo rophacinone use although residues were detected below the level of quantitation (LOQ) of 0.25 mg a.i./kg-bw. The ferruginous hawk mortality is attributed to interspecific/intraspecific fighting and the great horned owl mortality is attributed to a car collision. However, both animals appeared an emic during examination indicating blood loss, possibly accelerated by chlorophacinone, as cause of death. Further, hemorrhaging that may have occurred may not have been detectable due to the freezing of carcasses prior to

examination. Some evidence indicates that mi cro-hemmorhaging can be detected prior to carcass freezing but cannot be detected ot herwise (personal communication, Scott Larson, USFWS, June 25, 2010).

4.4. Use of Probit Slope Response Relationship to Provide Information on the Endangered Species Levels of Concern

As part of the risk characterizat ion, an interpretation of acute RQs for listed species is discussed. This interpretation is presented in terms of the chance of an individual event ( i.e ., mortality or immobilization) should exposure at the EEC actua lly occur for a species with sensitivity to chlorophacinone on par with the acute toxicity endpoint selected fo r RQ calculation. To accomplish this interpretation, the Agency uses the slope of the dose response relationship available from the toxicity study us ed to establish the acute toxicity measures of effect for each

78

### taxonomic group that is relevant to this assessment. The individual effects probability associated with the acute RQ is based on the mean estimate of the slope and an assumption of a probit dose response relationship. In addition to a single e ffects probability estimate based on the mean, upper and lower estimates of the effects probabilit y are also provided to account for variance in the slope, if available.

Individual effect probabilitie s are calculated based on an Ex cel spreadsheet tool IECV1.1 (Individual Effect Chance Model Version 1.1) deve loped by the U.S. EPA, OPP, Environmental Fate and Effects Division (June 22, 2004). The m odel allows for such calculations by entering the mean slope estimate (and the 95% confidence bounds of that estimate) as the slope parameter for the spreadsheet. In addition, the acute RQ is entered as the desired threshold.

5. Risk Characterization

Risk characterization is the integration of th e exposure and effects characterizations. Risk characterization is used to determine the potentia l for direct and/or indi rect effects to listed species or for modification to designated critic al habitat from the use of chlorophacinone to

control BTPDs. The risk charac terization provides an estimation ( Section 5.1 ) and a description ( Section 5.2 ) of the likelihood of adverse effects; articulates risk assessment assumptions, limitations, and uncertainties; and synthesizes an overall conclusion rega rding the likelihood of adverse effects to the assessed species or their designated critical habitat ( i.e

., NE; LAA; NLAA). In the risk estimation sect ion, RQs are calculated using standard EFED procedures explained in the following section. In the risk description section, additional analyses may be conducted to help characterize the potential for risk.

5.1. Risk Estimation

Risk is estimated by calculating the ratio of expos ure to toxicity. The endpoints in Table 4.1 are used to calculate RQs based on conservative terrestrial exposure assumptions. The most sensitive species among avian and mammalian speci es tested are used to calculate RQs and characterize the direct risk to listed species. This ratio is the RQ, which is then compared to acute LOCs for each category evaluated (USEPA, 2004a ). For acute exposure to terrestrial listed species the LOC is 0.1. For details regarding th e methods, parameter selection and equations for this risk estimation, see Section 3.3.

Exposure to terrestrial animals is considered fo r two general conditions: 1) primary exposure to bait and 2) secondary exposure to carcasses or poisoned animals. In the case of primary exposure, the concentration of active ingredient within the bait is consid ered to be the EEC. Therefore, the primary exposure EEC is 50 mg/kg-diet. To determine secondary exposure EECs, available literature concerning ca rcass residue concentrations we re considered. In previous assessments, open literature sources of chlorophaci none residue concentrati ons were referenced. Erickson and Urban (USEPA, 2004b) compiled this data (see Tables 4.2 and 4.3 ) and the latest ECOTOX bibliography (updated May 2010) did not i ndicate any additions. Based on the highest whole body residue concentrations, the EEC for secondary exposure to chlorophacinone via BTPD carcass is 2.24 mg a.i./kg-bw. The EEC for secondary exposure via incidentally exposed

79

### non-target granivores ( e.g. mice) is 5.8 mg a.i./kg-bw. For the complete rationale as to why these concentrations are used, see Section 3.3.

5.1.1. Risk to Birds and Herptiles

Based on an LD 50 

### value of 258 mg a.i./kg bw (calculations explained in Appendix J) and the acute listed species LOC of 0.1, no exceedences of the LOC occur for listed avian species based on a single acute dose

. However, based on an LC 50 

### value of 56 mg a.i./k g-diet exceedences of the LOC occur for five-day consumption of th e grain bait or chlorophacinone poisoned nontarget animals ( Table 5.1 ). Single dose LD 50 

### calculations are made in Appendix J for two species (California condor and New Mexican ridge-nosed rattlesn ake) representing the range of sizes of species assessed as birds. RQs base d on exposure to non-target animals from this analysis (0.0003 and 0.0035) are lowe r than RQs based on exposure to non-target animals for the

sub-acute LC 50 

### endpoint (0.104). Thus, the LC 50 

### value is the more conservative value. Therefore, risk to listed birds and herptiles is evaluated using the most sensitive LC 50 

### value based on avian toxicity tests. Exposure to chloropha cinone at concentrations below LOCs based on

LC 50 

### s will be considered a risk based on this uncertainty.

Because residue concentrations for invertebra tes are not as well characterized as residue

concentrations in rodents and available inverteb rate residue data does not exceed rodent residue concentrations, the mouse residue concentration is used as a surrogate for invertebrate residues. Five-day consumption of chlorophacinone poiso ned BTPDs does not exceed the LOC based on

the LC 50



### .

An avian reproduction study for chlorophacinone has been required but has yet to be submitted. In the absence of this study a nd any open literature st udy that may supplement it, risk of adverse

effects to avian and herptile reproduction canno t be precluded.

Table 5.1 Summary of RQ Values for Avian Species. RQs were calculated with an LC 50 

### of 56 mg a.i./kg-diet and RQs are presented for diet as tested.

Species RQ Bait RQ BTPD RQ mouse 1 Probability of Individual Effect at RQ 2

California condor * 0.04 0.104 1 in 14

Whooping crane 0.89 0.04 0.104 1 in 2.13

Eskimo curlew * ** 0.104 1 in 14

Northern Aplomado falcon * 0.04 0.104 1 in 14

Chirichaua leopard frog * ** 0.104 1 in 14

Mexican spotted owl * 0.04 0.104 1 in 14

Piping plover * ** 0.104 1 in 14



### 80Sonora tiger salamander * ** 0.104 1 in 14

Black-capped vireo * ** 0.104 1 in 14

Golden-cheeked warbler * ** 0.104 1 in 14

RQ = (Residue Concentration)/(LC 50 )

1 The mouse residue concentration of 5.8 mg a.i./kg-bw is used as a surrogate for invertebrate residues.

2 Highest RQ value was used to calculate the probability of individual effect. The LC 50 of 56 ppm was used as well as the slope of 1.49 obtained from the study (MRID 4 1513102). The generic probability of individual effect for birds and herpitles calculated using the LC 50 of 56 mg a.i./kg-diet, the slope of 1.49, and the LOC of 0.1 was ~1 in 14.7. Therefore, if any of the probabilities of individual ef fect are less than 1 in 14.7 there is an exceedance of the LOC. The probabilities of individual effect for each species exceeded the LOC.

Exceedances of LOC are in bold

* does not eat bait

** does not eat BTPDs



### 5.1.1.a. Risk to New Mexican Ridge-nosed Rattlesnake

It is not appropriate to assess dietary exposure to a rattlesnake using a 5-day LC 50 

### because based on life history information dietary exposure will not occur on a daily basis. Rather, it is more appropriate to use a single dose LD 50 

### value because rattlesnakes feed up to a few times per year (Howard, 2005). Weight information is not availabl e for this species but for the purposes of this analysis, weights for a small rattlesnake will be assumed to be 50 grams and 500 grams. As

discussed in Section 3.3.2.b , maximum snake prey size can be related to snake mass. From this equation, maximum prey sizes are 66 grams and 777 grams for the 50 gram and 500 gram snake, respectively 9 

### . Because the New Mexican ridge-nosed rattlesnake is a small rattlesnake, it is more likely that it would prey upon a small non-ta rget granivore like a mouse rather than a BTPD. Therefore, a residue concentration of 5.8 mg a.i./kg-bw will be assumed for the prey

item.

50 gram snake:

Dose of chlorophacinone: 66,000 mg * 0.0000058 = 0.383 mg a.i. Weight normalized dose: 0.383 mg a.i. ÷ 0.1 kg bw = 3.83 mg a.i./kg bw Adjusted LD 50 

### (Minaeu et al, 1996) (50 g/178 g) * 258 mg a.i./kg bw = 213 mg a.i./kg bw Risk Quotient: 3.83 mg a.i. /kg bw ÷ 213 mg a.i./kg bw = 0.018

500 gram snake:

Dose of chlorophacinone: 777,000 mg * 0.0000058 = 4.51 mg a.i. Weight normalized dose: 4.51 mg a.i. ÷ 0.5 kg bw = 9.02 mg a.i./kg bw Adjusted LD 50 

### (Minaeu et al, 1996) (500 g/178 g) * 258 mg a.i./kg bw = 301 mg a.i./kg bw Risk Quotient: 9.02 mg a.i. /kg bw ÷ 301 mg a.i./kg bw = 0.030

9 Prey size (g) = Snake mass 1.071 (g)



### 81

### 82 5.1.2. RQs do not vary significantly wi th a range of body sizes. Both RQs calculated are below the LOC for terrestrial endangered species (LOC=0.1). Although the RQ s indicate that no effect is expected, risk to reproduction cannot be prec luded due to lacking av ian reproduction data. Indirect effects will be discussed separately and a separate determination will be made.

Risk to Mammals

Exposure to listed mammals is evaluated using the most sensitive LD 50 

### value based on mammalian toxicity tests. Ingest ion rates and weight-adjusted LD 50 

### s are calculated and presented in Table 5.2. Wet weight ingestion rates are used for assessing secondary exposure. Grain bait is assumed to be dry and therefore dry weight ingestion rates are used for assessing primary exposure. These ingestion rates and LD 50 

### s are used, in part, to calculate RQs presented

in Table 5.3 . Exceedences of the LOC are indicated in bold. RQs for all mammals for all assessed exposure pathways exceed th e Acute Listed Species LOC of 0.1.

Table 5.2 Calculation of Ingestion Rate and Adjusted LD 50 

### for mammals

Listed Mammalian Species Body Weight Ingestion Rate (dry weight)

(g/day) 1 Ingestion Rate (wet weight)

(g/day) 2 Adjusted LD 50 (mg a.i./kg bw) 3

Mammals with potential to consume grain bait
Grizzly bear 102000 3077.07 * 0.02

Preble’s meadow jumping mouse 13 1. 94 * 0.18

Carnivores

Black-footed ferret 635 47.31 147.84 0.07
Jaguar 36363 1318.04 4118.89 0.02

Gulf Coast jaguarundi 4500 23 6.60 739.36 0.04

Canada lynx 5100 262.23 819.48 0.04

Ocelot 11 300 504.31 1575.97 0.03 Gray wolf 18000 739.44 2310.74 0.03
* no wet weight to dry weight conversion was calculate d because it is assumed that the bait is in dry weight.

1 Dry weight ingestion rate is calculated using the “all mammals” allometric equation from EPA 1993.

2 The ingestion rate in terms of wet weight is calculated using the following equation: Ingestion Rate (wet weight) = Ingestion Rate (dry weight)/(1-0.68)

3 The Adjusted LD 50 is calculated using the following equation: Adjusted LD 50 = LD 50 *[(body weight (in grams) of the test animal used in the study)/(body weight of the listed mammalian species)]^0.25 In this case, the LD 50 is 0.16 and the body weight (in grams) of the test animal used in the study was 20 grams.83Table 5.3 Summary of RQ Values for Mammalian Species. RQ descriptions are qualified with the associated toxicity value.RQs were calculated with an LD50of 0.16 mg a.i./kg bw.SpeciesIngestion Rate(wet weight)(g/day)Dose-basedEEC for bait(mg/kgbw/day)1RQ Bait2Dose-basedEEC for BTPD(mg/kgbw/day)1RQ BTPD2Dose-basedEEC for mouse(mg/kgbw/day)1RQ mouse2Probability ofIndividualEffect at RQ3Grizzly bear3,077.071.50875.420.0683.380.1758.751 in 1Black-footedferret47.31**0.5227.451.35019.291 in 1Jaguar1,318.04**0.25412.690.65732.851 in 1Gulf Coastjaguarundi236.60**0.3689.200.95323.821 in 1Canada lynx262.23**0.3609.000.93223.301 in 1Preble’smeadowjumping mouse1.947.44341.35********1 in 1Ocelot504.31**0.31210.410.80926.961 in 1Gray wolf739.44**0.2889.590.74524.821 in 1* does not eat bait** does not eat BTPDs or non-target animals1The Dose-based EEC is calculated using the following equation:(Residue (mg/kg-diet [ww])*FI (kg-diet [ww]/day))/(body weight of the listed species (in grams)/1000)Residues are: 50 mg a.i./kg for bait; 2.24 kg-diet [ww]/dayfor BTPDs; 5.8 kg-diet [ww]/day for non-target animalsFI (kg-diet [ww]/day) is calculated by the following equation:Ingestion Rate (wet weight) (g/day)/10002RQ is calculated using the following equation:RQ=Dose-based EEC/Adjusted LD503The highest RQ value was used to calculate the probability of individual effect. The LD50of 0.16 mg a.i./kg bw was used as well as the generic slope of 4.5 asper original Agency assumptions of typical slope cited in Urban and Cook (1986). The generic probability of individual effectfor mammals calculating using theLD50of 0.16 mg a.i./kg bw, the generic slope of 4.5, and the LOC of 0.1 was ~1 in 294,000. Therefore, ifany of the probabilitiesof individual effect are lessthan 1 in 294,000 there is an exceedanceof the LOC. The probabilities of individual effectfor each species exceeded the LOC.Exceedances of LOC are in bold

### 5.1.3. Risk to Terrestrial Invertebrates

Toxicity to listed terrestrial invertebrates (spe cifically the American burying beetle and the Salt Creek tiger beetle) was evaluate d qualitatively (as chlorophacinone residues in the dosed rat carcasses in the study discussed in Section 4.2.3 (MRID 47383001) were not available). The study described in Section 4.2.3 (MRID 47383001) showed larval survival effects to N.

orbicollis which is supposedly the n earest extant relative to the American burying beetle (MRID 47383001). Based on this information, it was assume d that the listed Amer ican burying beetle would also experience larv al survival effects if exposed to chlorophacinone residues. Since the American burying beetle is found within the ac tion area, it may be expos ed to chlorophacinonedosed carcasses. Furthermore, the larvae of the Salt Creek tiger beetle eat insects and may also experience survival effects due to chlorophacinone residues. Since the Salt Creek tiger beetle is

also found within the action ar ea and therefore has the potent ial to feed on chlorophacinone contaminated insects, this species may also experience larval surv ival effects due to chlorophacinone residues.

5.1.4. Primary Constituent Elements of Designated Critical Habitat

For chlorophacinone use, the assessment endpoints for designated critical habitat PCEs involve the same endpoints as those being assessed for po tential direct and indirect effects above. Therefore, the preliminary effects determinations for direct and indirect effects are used as the basis of the effects determination for potential modification to designa ted critical habitat.

All of the assessment endpoints for the PCEs of designated critical habitat for the Salt Creek tiger beetle, California condor, w hooping crane, Canada lynx, Preb le’s meadow jumping mouse, Mexican spotted owl, piping plover, New Mexican ridge-nosed rattlesnake, and the gray wolf involve potential direct effects to the organism. Through the risk determinations made for listed bird, mammal, herptile and invertebrate species, the potential for effect s to prey base were evaluated. Indirect effects through loss of the prey base or habita t loss (burrows) are seen for the Salt Creek tiger beetle, Califor nia condor, whooping crane, Ca nada lynx, Preble’s meadow jumping mouse, Mexican spotted owl, piping plov er, New Mexican ridge-nosed rattlesnake, and the gray wolf. Effects to the prey base are ex pected because the Acute Risk LOC of 0.5 (the LOC used to evaluate risk to non-listed speci es) is exceeded for mammals, birds and herptiles 10


### (EPA 2004a). Invertebrate toxicity data indicate that there are direct effects on reproduction for invertebrate species whose larvae are exposed to chlorophacinone residues . This exposure is possible and therefore direct eff ects to invertebrates including th e Salt Creek tiger beetle are expected. Based on these data, effects to the prey base are possible for li sted species that prey upon birds, mammals, herptiles, or invertebrates. The Agency does not currently have a method to analyze effects to populations based on effects to individuals. Because this effect cannot be analyzed, risk is presumed and effects to ma mmal, bird, herptile, and invertebrate prey populations is presumed. Therefor e prey base effects are presum ed for Salt Creek tiger beetle, California condor, whooping crane, Canada lynx, Preble’s meadow jumping mouse, Mexican spotted owl, piping plover, New Mexican ridge-nosed rattlesnake, and the gray wolf. The only

10 Maximum RQ for mammals = 75.42; Maximum RQ for birds (and herptiles) = 0.89;



### 84

### 85 impact to habitat would be th e loss of BTPD burrows. Based on the life history information available, none of the species that may be aff ected with designated cr itical habitat use BTPD burrows therefore this loss of burrows is not expe cted to have an adverse impact on these species ( Attachment 1 ). The preliminary effects determination for all PCEs for all species that may be affected is provided in Table 5.5

5.2. Risk Description

The risk description synthesizes overall conclusi ons regarding the likelihood of adverse impacts leading to a preliminary effects determination ( i.e ., NE, NLAA, or LAA) for the assessed species and the potential for modification of their designated critical ha bitat based on analysis of RQs and a comparison to the LOC. The final determin ation is made after the spatial analysis is completed at the end of the risk description, Section 5.2 . In Section 5.2.3 , a discussion of any potential overlap between areas where potential usage may occur and areas where species are expected to occur (including any de signated critical habitat) is pres ented. If there is no overlap of the species habitat and occurrence sections with the Potential Area of MA Effects a NE

determination is made.

If the RQs presented in the Risk Estimation ( Section 5.1 ) show no direct effects for the assessed species and no modification to PCEs of the desi gnated critical habitat, which was already

described in Section 5.1.4 , a NE determination is made, based on the use of chlorophacinone to control BTPDs within the action area. However, if the LOC for direct effects is exceeded the Agency concludes a preliminary MA determinat ion for the FIFRA regulatory action regarding the use of chlorophacinone to control BTPDs.

A summary of the risk estimation results are provided in Table 5.4 for direct and indirect effects to the listed species that may be affected and in Table 5.5 for the PCEs of their designated critical habitat.Table 5.4. Risk Estimation Summary for ChlorophacinoneSpeciesLOC Exceedences (Yes/No)Description of Results of Risk EstimationDirect effects1:yesDirect effects are expected for the grizzly bear based on the potential for this species to consume thechlorophacinone bait (RQ of 75.42 which exceeds the LOC of 0.1) or other prey items that may have consumedthe chlorophacinone bait (RQ of 3.38 for exposure to BTPDs and RQ of 8.75 for exposure to non-target animals,both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence ofchronic data; however, growth and reproductive effects are not expected because mortality typically occurs as aresult of acute exposure.Grizzly bearIndirect effects2:yesIndirect effects from the loss of the prey base are also expected because effects to individuals within populationshave been demonstrated in mammals ranging in size from 13 to 36,363 grams with RQs ranging from 19 to 41.No indirect effects from habitat loss are expected because this species does not use BTPD burrows.Direct effects:yesReproductive effects are expected for the American burying beetle. The American burying beetle usesmammalian and avian carcasses as a food resource duringtheir reproduction cycle.Dosed carcasses negativelyaffected number of emerged beetles (MRID 47383001).American buryingbeetleIndirect effects:yesIndirect effects from the loss of the prey base are expected because effects toindividuals within populations havebeen demonstrated in mammals, birds, and invertebrates.No indirect effects fromhabitat loss are expectedbecause this species does not use BTPD burrows.Direct effects:yesReproductive effects are expected for the Salt Creek tiger beetle. Salt Creek tiger beetle larvae are potentiallyexposed to chlorophacinone residues through chlorophacinone exposed terrestrial invertebrates. Dosed carcassesin a burying beetle study negatively affected number of emerged beetles (MRID 47383001). Similar affects areexpected for the Salt Creek tiger beetle.Salt creek tiger beetleIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. This species uses mud banks of streams and seeps in association with saline wetlands and exposed mudflats of saline wetlands which is distinct from the short grass prairie associated with BTPD habitat. No indirecteffects from habitat loss are expected because this species does not use BTPD burrows.Direct effects:yesDirect effects to the California condorare expected through theirpotential exposure to prey items that may haveconsumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data.California condorIndirect effects:noNo indirect effects from the loss of prey base are expected becausethis species’ range does not overlap withBTPD range. No indirect effects from habitat loss are expected because this species does not use BTPDburrows.Whooping craneDirect effects:Direct effects tothe whooping crane are expected to occur basedon the potential for this species to consume the86LOC Exceedences (Yes/No)SpeciesDescription of Results of Risk Estimationyeschlorophacinone bait (RQ of 0.89 which exceeds the LOC of 0.1) or other prey items that may have consumedthe chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1).Growth and reproductive effects cannot be precluded due to the absence of chronic data.Indirect effects:yesIndirect effects from the loss of the prey base are also expected because effects to individuals within populationshave been demonstrated in mammals, birds, and invertebrates. No indirect effects from habitat loss are expectedbecause this species does not use BTPD burrows.Direct effects:yesDirect effects to the Eskimo curlew are expected to occur based on the potential for this species to consume preyitems that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which isused as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growthand reproductive effectscannot be precluded due to the absence of chronic data.Eskimo curlewIndirect effects:yesIndirect effects from the loss of the prey base are expected because effects toindividuals within populations havebeen demonstrated in terrestrial invertebrates. No indirect effects from habitat loss are expected because thisspecies does not use BTPD burrows.Direct effects:yesDirect effects to the northern Aplomado falcon are expected through their potential exposure to prey items thatmay have consumed the chlorophacinone bait (RQ of 0.104 for exposureto non-target animals which exceedsthe LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data.Northern AplomadofalconIndirect effects:yesIndirect effects from the loss of the prey base are also expected because effects to individuals within populationshave been demonstrated in mammals, birds, and invertebrates. No indirect effects from habitat loss are expectedbecause this species does not use BTPD burrows.Direct effects:yesDirect effects are expected for the black-footed ferret based on the potential for this species to consume preyitems that may have consumed the chlorophacinone bait (RQ of 7.45 for exposure to BTPDs and RQ of 19.29 forexposure to non-target animals, both which exceed the LOC of 0.1). Significant exposure is expected to occurbecause black-footed ferrets prey primarily on BTPDs. Growth and reproductive effects cannot be precludeddue to the absence of chronic data; however, growth and reproductive effects are not expected because mortalitytypically occurs as a result of acute exposure.Black-footed ferretIndirect effects:yesIndirect effects from the loss of the prey base are also expected because effects to individuals within populationshave been demonstrated in mammals, birds, and invertebrates. In addition, this species preys almost exclusivelyon BTPDs. Indirect effects from habitat loss are expected because this species uses BTPD burrows.Direct effects:yesDirect effects to the Chirichaua leopard frog are expected to occur based onthe potential for this species toconsume prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-targetanimals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth andreproductive effects cannot be precludeddue to the absence of chronic data.Chirichaua leopard frogIndirect effects:yesIndirect effects from the loss of the prey base are expected because effects toindividuals within populations havebeen demonstrated in terrestrial invertebrates and birds. No indirect effects from habitat loss are expectedbecause this species does not appear to use BTPD burrows.87LOC Exceedences (Yes/No)SpeciesDescription of Results of Risk EstimationDirect effects:yesDirect effects are expected for the jaguar based on the potential for this species to consume prey items that mayhave consumed the chlorophacinone bait (RQ of 12.69 for exposure to BTPDs and RQ of 32.85 for exposure tonon-target animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precludeddue to the absence of chronic data; however, growth and reproductive effects are not expected because mortalitytypically occurs as a result of acute exposure.JaguarIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. Jaguars – particularly males of the northernreaches – are known to have large home ranges thatencompass a variety of plant communities, including:Maderan evergreen-woodland,subalpine conifer forest,semidesert shrubland, and Sonoran desert scrub. Washes and riparian areas with dense vegetative growth mayalso be valuable movement corridors. These habitats are distinct from the short grass prairie associated withBTPD habitat. No indirect effects from habitat loss are expected because this species does not use BTPDburrows.Direct effects:yesDirect effects are expected for the Gulf Coast jaguarundi based on the potential for this species to consume preyitems that may have consumed the chlorophacinone bait (RQ of 9.20 for exposure to BTPDs and RQ of 23.82 forexposure to non-target animals, both which exceed the LOC of 0.1). Growth and reproductiveeffects cannot beprecluded due to the absence of chronic data; however, growth and reproductive effects are not expected becausemortality typically occurs asa result of acute exposure.Gulf Coast jaguarundiIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. This species is found in chaparral plant communities and dense brushy areas near streams and riverswhich are distinct from the short grass prairie associatedwith BTPD habitat. No indirect effects from habitatloss are expected because this species does not useBTPD burrows.Direct effects:yesDirect effects to the Canada lynx are expected to occur based on the potential for this species to consume preyitems that may have consumed the chlorophacinone bait (RQ of 23.30 for exposure to non-target animals and RQof 9.00 for exposure to BTPDs both of which exceed the LOC of 0.1). Growth and reproductive effects cannotbe precluded due to the absence of chronic data; however, growth and reproductiveeffects are not expectedbecause mortality typically occursas a result of acute exposure.Canada lynxIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. The Canada lynx is associated with the southern, transitional reaches of the cool and moist boreal forest.Where it occurs at these lower latitudes, the borealforest forms a mixed conifer and conifer-hardwoodlandscape. These habitat areas are distinct from the short grass prairie associatedwith BTPD habitat. Noindirect effects from habitat loss are expected because this species does not use BTPD burrows.Preble’s meadowjumping mouseDirect effects:yesDirect effects to the Preble’s meadow jumping mouse are expected to occur based on the potential for thisspecies to consume the chlorophacinone bait (RQ of 41.35 which exceeds the LOC of 0.1). Growth andreproductive effects cannot be precludeddue to the absence of chronic data; however, growth and reproductiveeffects are not expected because mortality typically occurs as a result of acute exposure.88LOC Exceedences (Yes/No)SpeciesDescription of Results of Risk EstimationIndirect effects:yesIndirect effects from the loss of the prey base are expected because effects toindividuals within populations havebeen demonstrated in terrestrial invertebrates. Although this species makes nests both above and below ground,it does not appear to use other species’ burrows.Direct effects:yesDirect effects are expected for the ocelot based on the potential for this species to consume prey items that havemay consumed the chlorophacinone bait (RQ of 10.41 for exposure to BTPDs and RQ of 26.96 for exposure tonon-target animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precludeddue to the absence of chronic data; however, growth and reproductive effects are not expected because mortalitytypically occurs as a result of acute exposure.OcelotIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. Ocelots appear to use areas of dense cover, and in the northern part of the range hunt in brushy forestsand semi-arid deserts. In the southern part of its range, ocelot habitat includes tropical forests, mountain slopes,and pampas (grasslands). These habitat areas are distinct from the short grass prairie associated with BTPDhabitat. No indirect effects fromhabitat loss are expected because thisspecies does not use BTPD burrows.Direct effects:yesDirect effects to the Mexican spotted owl are expected to occur based on the potential for this species toconsume prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-targetanimals which exceeds the LOC of 0.1). Growth andreproductive effects cannot be precluded due to theabsence of chronic data.Mexican spotted owlIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. Mexican spotted owls are found in old-growth or mature forests with unevenly aged stands of trees, highcanopy, multi-storied levels, and high tree density as wellas canyons with riparian or conifer communities. InArizona and New Mexico they are found in habitats associated with mixed conifer, pine-oak, Arizona cypress,oak woodlands, and associated riparian forests. Thesehabitat areas are distinct from the short grass prairieassociated with BTPD habitat. Noindirect effects from habitat loss areexpected because this species does notuse BTPD burrows.Direct effects:yesDirect effects to the piping plover are expected to occur based on the potential for this species to consume preyitems that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, whichis used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effectscannot be precluded due to the absence of chronic data.Piping ploverIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. The plover’s home range within BTPD range is usually limited to the wetland, lakeshore, or section ofbeach where its nest is located. No indirect effects fromhabitat loss are expected because this species does notuse BTPD burrows.New Mexican ridgenosed rattlesnakeDirect effects:yesNo direct effects based on survival to the New Mexican ridge-nosed rattlesnake are expected to occur (seeSection 5.1.1.a. RQs of 0.018 for a 50 gram snake and RQ of 0.030 for a 500 gram snake. Neither of these RQsexceeds the LOC of 0.1). However, growth and reproductive effects cannotbe precluded due to the absence ofchronic data.89LOC Exceedences (Yes/No)SpeciesDescription of Results of Risk EstimationIndirect effects:yesIndirect effects from a loss of the prey base are expected because effects to individuals within populations havebeen demonstrated in mammals, birds, and invertebrates.No indirect effects fromhabitat loss are expectedbecause this species does not appear to use BTPD burrows.Direct effects:yesDirect effects to the Sonora tiger salamander are expected to occur based onthe potential for this species toconsume prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-targetanimals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth andreproductive effects cannot be precludeddue to the absence of chronic data.Sonora tigersalamanderIndirect effects:noNo indirect effects from the loss of prey base or loss of habitat (BTPD burrows) are expected because thisspecies’ range does not overlap with BTPD range.Direct effects:yesDirect effects to the black-capped vireo are expected to occur based on the potential for this species to consumeprey items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, whichis used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effectscannot be precluded due to the absence of chronic data.Black-capped vireoIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. Black-capped vireos are found in mixed deciduous/evergreen shrub land. Breeding vireos use shrubbygrowth of irregular height and distribution with spaces the small thickets and clumps and with vegetativeextending to ground level. These habitat areas are distinct from the short grass prairie associated with BTPDhabitat. No indirect effects from habitat loss are expected because this species does not use BTPD burrows.Direct effects:yesDirect effects to the golden-cheekedwarbler are expected to occur based onthe potential for this species toconsume prey items that have consumed the chlorophacinonebait (RQ of 0.104 for exposure to non-targetanimals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth andreproductive effects cannot be precludeddue to the absence of chronic data.Golden-cheekedwarblerIndirect effects:noNo indirect effects from loss of prey base are expected because thisspecies’ habitat is distinct from BTPDhabitat. Golden-cheeked warblers are found in mixed Ashe-juniper and oak woodlands in ravines and canyons.They spend summers in open canopy forest and winters in closed canopy forests. These habitat areas are distinctfrom the short grass prairie associatedwith BTPD habitat. No indirecteffects from habitat loss are expectedbecause this species does not use BTPD burrows.Direct effects:yesDirect effects to the gray wolf are expected to occur based on the potentialfor this species to consume prey itemsthat have consumed the chlorophacinone bait (RQ of 24.82 for exposure to non-target animals and RQ of 9.59for exposure to BTPDs both of which exceed the LOC of0.1). Growth and reproductive effects cannot beprecluded due to the absence of chronic data; however, growth and reproductive effects are not expected becausemortality typically occurs as a result of acute exposure.Gray wolfIndirect effects:yesIndirect effects from the loss of the prey base are also expected because effects to individuals within populationshave been demonstrated in mammals, birds, and invertebrates. No indirect effects from habitat loss are expectedbecause this species does not use BTPD burrows.901Direct effects are survival, growth, and reproduction effects to the individuals (juveniles and adults) of each listed species(terrestrial phase only if the species is aquatic or semiaquatic)2Indirect effects are survival, growth, and reproduction effectsto the individuals of each listed species via effects on preyor habitat (burrows).Table 5.5. Table 5.5 Risk Estimation Summary for Chlorophacinone - Effects to DesignatedCritical Habitat (PCEs)SpeciesAssociatedwith aDesignatedCriticalHabitatPCEsLOCExceedances(yes/no)Description of Results of Risk Estimation(1) Non-vegetated streambanks and mid-channel areas, located adjacent toand between saline stream edges and barren salt flats in saline and freshwaterwetlands, in assemblages that are within 4 mi (6 km) of one another.(2) Moist, barren salt flats with:(a) Salmo and Saltillo soils or Lamo, Gibbon-Saltine, Obert, and Zoe soilswith Salmo and Saltillo inclusions:(b) Soil electroconductivity ranging from 2,016.0 mS/m to 2,992.2 mS/m;(c) Soil moisture ranging from 43.5 percent to 51.7 percent; and(d) Differential hydraulic pressures that create evaporation and result inexposed salt on soil surfaces.Salt Creektiger beetle(3) A natural hydrologic regime resulting in annual high flows in salinestreams in the early spring and summer, and natural elevation changes ingroundwater levels to hydrate saline wetlands located on the floodplain.YesReproductive effects are expected for the SaltCreek tiger beetle. Salt Creek tiger beetlelarvae are potentially exposed tochlorophacinone residues throughchlorophacinone exposed terrestrialinvertebrates. Dosed carcasses in a buryingbeetle study negatively affected number ofemerged beetles (MRID 47383001). Similaraffects are expected for the Salt Creek tigerbeetle. No indirect effects from loss of preybase are expected because this species’ habitatis distinct from BTPD habitat. This speciesuses mud banks of streams and seeps inassociation with saline wetlands and exposedmud flats of saline wetlands which is distinctfrom the short grass prairie associated withBTPD habitat. No indirect effects from habitatloss are expected becausethis species does notuse BTPD burrows.91(4) The presence of abundant and diverse flying and non-flying invertebrateprey species belonging to the orders Coleoptera, Orthoptera, Hemiptera,Hymenoptera, Odonata, Diptera, or Lepidoptera.PCEs were not described for the California condor. However, several factorswere considered in designating critical habitat:The Sespe-Piru, Mantilija, Sisquoc-San Rafael, and the Hi Mountain-Beartrapareas were considered critical for nesting and related year-long activities.The Mount Pinos and Blue-Ridge areas wereconsidered critical for roosting.The Tejon Ranch, Kern County Rangelands, and Tulare County Rangelandswere considered critical for feeding and other related activities; specifically,the Tejon County Rangelands are important because it is the only feedingarea close to the Sespe-Piru nesting area.CaliforniacondorFurther, areas of open range with limited disturbance that provide food areneeded within the designated areas to maintainthe species, since foodavailability is directly related tocondor distribution and reproduction.YesDirect effects to theCalifornia condor areexpected through theirpotential exposure toprey items that may have consumed thechlorophacninone bait (RQ of 0.104 forexposure to non-targetanimals which exceedsthe LOC of 0.1). Growth and reproductiveeffects cannot be precluded due to the absenceof chronic data. No indirect effects due to preybase loss are expected because this speciesonly occurs in areas adjacent to BTPD range.No indirect effects from habitat loss areexpected because this species does not useBTPD burrows.Although PCEs were not specifically described for the whooping crane it wasstated that each of the five factors normally associated with PCEs ((1) Spacefor individual and population growth and for normal behavior; (2) Food,water, air, light, minerals, or other nutritional or physiological requirements;(3) Cover or shelter; (4) Sites for breeding, reproduction, or rearing ofoffspring; and generally, (5) Habitats that are protected from disturbances orare representative of the geographicaldistribution of the listed species)pertain to the whooping crane and are summarized below:WhoopingcraneWhooping cranes are territorial; pairs require hundreds of acres ofundisturbed wetland habitat and unmated birds require undefended territory.Refuges in Idaho, Colorado, and New Mexico were originally designated aspart of the critical habitat to add space for a growing new flock. However,these refuges were later removed fromthe critical habitat designation due tothe failure of whooping crane reintroduction in these areas.YesDirect effects to the whooping crane areexpected to occur based on the potential forthis species to consume the chlorophacninonebait (RQ of 0.89 which exceeds the LOC of0.1) or other prey items that have consumedthe chlorophacninone bait (RQ of 0.104 forexposure to non-targetanimals which exceedsthe LOC of 0.1). Growth and reproductivedata cannot be precluded due to the absence ofchronic data. Indirect effects from the loss ofthe prey base are also expected because effectsto individuals within populations have beendemonstrated in mammals, birds, andinvertebrates. No indirect effects from habitatloss are expected becausethis species does notuse BTPD burrows.92All of the designated critical habitatareas provide for the nutritional andphysiological needs of the cranes. Thisincludes the tidal flats and marshes ofAransas that provide crustaceans and mollusks, the spring migration marshesthat provide frogs, fish,crayfish, and other small animals, and the fallmigration stopover locations where cranesfeed primarily on waste grains andinsects.Whooping cranes require open spaces,primarily sand and gravel bars inrivers and lakes, for nightly roosting. These features appear to be one of themajor factors in the selection of habitat by cranes.With regard to breeding, the Grays Lake National Wildlife Refuge in Idahowas previously designated as critical habitat in order to provide additionalnesting habitat. However, all of the designated critical habitat provides areasessential to rearing young. Cranes also require undisturbed wetland roostingsites and do not tolerate disturbance to themselves or their habitat.93Boreal forest of multiple succesional stages.Snowshoe hares and their preferred habitat conditions, which include low anddense vegetation that protrudes above the snow, and mature multistoriedstands with conifer boughs at the snow surface.Winter snow conditions of deep powder present for extended periods of time.Potential den sites characterized byabundant coarse woody debris.Canada lynxMatrix habitat (e.g., hardwood forest, dry forest, non-forest, or other habitattypes that do not support snowshoe hares) which connect patches of borealforest foraging sites used by the lynx within a home rangeYesDirect effects to the Canada lynx are expectedto occur based on the potential for this speciesto consume prey items that have consumed thechlorophacninone bait (RQ of 23.30 forexposure to non-target animals and RQ of 9.00for exposure to BTPDs both of which exceedthe LOC of 0.1). Growth and reproductiveeffects cannot be precluded due to the absenceof chronic data; however, growth andreproductive effects arenot expected becausemortality typically occurs as a result of acuteexposure. No indirect effects from loss of preybase are expected because this species’ habitatis distinct from BTPD habitat. The Canadalynx is associated with the southern,transitional reaches of the cool and moistboreal forest. Where it occurs at these lowerlatitudes, the boreal forest forms a mixedconifer and conifer-hardwood landscape.These habitat areas are distinct from the shortgrass prairie associatedwith BTPD habitat.No indirect effects from habitat loss areexpected because this species does not useBTPD burrows.Riparian corridors formed and maintained by normal, dynamic,geomorphological, and hydrologic processes that create and maintain riverand stream channels, floodplains, and floodplain benches and promotepatterns of vegetation favorable to the Preble’s meadow jumping mouse,containing dense, riparian vegetation consisting of grasses, forbs, and shrubs,or any combination thereof, in areas along rivers and streams, that normallyprovide open water through the mouse’s active season.The riparian areas must also include specific movement corridors that provideconnectivity between and within populations.These could be riparian corridors with less vegetative cover, or includehuman disturbances such as erosion control, travel ways under bridges, alongditches and canals, and through culverts.Preble’smeadowjumpingmouseAdjacent areas of low disturbance in floodplains and uplands, such as hayedfields, grazed pasture, andother unplowed agricultural fields, restored minelands, recreational trail areasand urban-wildland interfaces.YesDirect effects to the Preble’s meadow jumpingmouse are expected to occur based on thepotential for this species to consume thechlorophacninone bait (RQ of 41.35 whichexceeds the LOC of 0.1). Growth andreproductive effects cannot be precluded due tothe absence of chronic data; however, growthand reproductive effects are not expectedbecause mortality typically occurs as a resultof acute exposure. Indirect effects from loss ofprey are expected because effects toindividuals within populations have beendemonstrated in terrestrial invertebrates.Although this species makes nests both aboveand below ground, it does not appear to useother species’ rodent burrows.94A range of tree species, including mixed conifer, pine-oak, and riparian foresttypes, composed of different tree sizes reflecting different stages of trees, 30-45% of which are trees with a 12 inch or greater trunk diameter whenmeasured 4.5 feet off of the ground.A shade canopy created by the tree branches covering 40 percent or more ofthe groundLarge dead trees (snags) with a trunk diameter of at least 12 inches (0.3meters) when measured at 4.5 feet(1.4 meters) from the ground.High volumes of fallen trees and other woody debris;A wide range of tree and plant species, including hardwoods; andAdequate levels of residual plant cover to maintain fruits, seeds, and allowplant regeneration.Presence of water which typically provides cooler temperatures and higherhumidity than the nearby areas.Clumps of stringers of mixed-conifer, pine-oak, pinyon-juniper, and/orriparian vegetation;Canyon wall containing crevices, ledges, or caves; andMexicanspotted owlHigh percent of ground litter and woody debris.YesDirect effects to the Mexican spotted owl areexpected to occur based on the potential forthis species to consume prey items that haveconsumed the chlorophacninone bait (RQ of0.104 for exposure to non-target animals whichexceeds the LOC of 0.1). Growth andreproductive effects cannot be precluded due tothe absence of chronic data. No indirecteffects from loss of prey base are expectedbecause this species’ habitat is distinct fromBTPD habitat. Mexican spotted owls are foundin old-growth or mature forests with unevenlyaged stands of trees, high canopy, multi-storiedlevels, and high tree density as well as canyonswith riparian or conifer communities. InArizona and New Mexico they are found inhabitats associated with mixed conifer, pineoak, Arizona cypress, oak woodlands, andassociated riparian forests. These habitat areasare distinct from the short grass prairieassociated with BTPD habitat. No indirecteffects from habitat loss are expected becausethis species does not use BTPD burrows.The PCEs that support foraging, roosting, and sheltering habitat componentsfor the wintering piping plover are:(1) Intertidal sand beaches (includingsand flats) or mud flats (between theMLLW [mean lower low water] and annual high tide) with no, or very sparse,emergent vegetation for feeding. In some cases, these flats may be covered orpartially covered by a mat of blue-green algae.(2) Unvegetated or sparsely vegetated sand, mud, or algal flats above annualhigh tide for roosting. Such sites may have debris or detritus and may havemicro-topographic relief (less than 20in (50 cm) above substrate surface)offering refuge from high winds and cold weather.(3) Surf-cast algae for feeding.(4) Sparsely vegetated backbeach, whichis the beach area above mean hightide seaward of the dune line, or in cases where no dunes exist, seaward of adelineating feature such as a vegetation line, structure, or road. Backbeach isused by plovers for roosting and refuge during storms.Piping plover(5) Spits, especially sand, running into water used for foraging and roosting.YesDirect effects to the piping plover are expectedto occur based on the potential for this speciesto consume prey items that have consumed thechlorophacinone bait (RQ of 0.104 forexposure to non-target animals, which is usedas a surrogate for invertebrate prey, whichexceeds the LOC of 0.1). Growth andreproductive effects cannot be precluded due tothe absence of chronic data. No indirecteffects are expected because this species’habitat is distinct from BTPD habitat. Theplover’s home range with BTPD range isusually limited to the wetland, lakeshore, orsection of beach where its nest is located. Noindirect effects from habitat loss are expectedbecause this species does not use BTPDburrows.95(6) Salterns, or bare sand flats in the center of mangrove ecosystems that arefound above mean high water and are only irregularly flushed with seawater.(7) Unvegetated washover areas with little or no topographic relief forfeeding and roosting. Washover areasare formed and maintained by theaction of hurricanes, storm surges, or other extreme wave actions.(8) Natural conditions of sparse vegetation and little or no topographic reliefmimicked in artificial habitat types (e.g., dredge spoil sites.)The following PCEs, taken from the critical habitat designation for thenorthern Great Plains breeding population of the piping plover, encompasspiping plover habitat outside of the designated wintering grounds of thespecies.The one overriding primary constituent element (biological) that must bepresent at all sites is the dynamicecological processes that create andmaintain piping plover habitat.The biological primary constituent element,i.e., dynamic ecologicalprocesses, creates different physicalprimary constituent elements on thelandscape. These habitat types or physical primary constituent elements thatsustain the northern Great Plains breeding population of piping plovers aredescribed as follows:On prairie alkali lakes and wetlands, the physical primary constituentelements include –(1) Shallow, seasonally to permanently flooded, mixosaline to hypersalinewetlands with sandy to gravelly, sparsely vegetated beaches, salt-encrustedmud flats, and/or gravelly salt flats;(2) Springs and fens along edges of alkali lakes and wetlands; and(3) Adjacent uplands 200 feet (61 m) above the high water mark of the alkalilake or wetland.On rivers the physical primary constituent elements include – sparselyvegetated channel sandbars, sand andgravel beaches on islands, temporarypools on sandbars and islands, and the interface with the river.On reservoirs the physical primary constituent elements include – sparselyvegetated shoreline beaches, peninsulas, islands composed of sand, gravel, orshale, and their interface with the water bodies.On inland lakes (Lake of the Woods) the physical primary constituentelements include – sparsely vegetated and windswept sandy to gravellyislands, beaches, and peninsulas, and their interface with the water body.96PCEs were not described for the New Mexican ridge-nosed rattlesnake byname. However, the critical habitat listing notice identified certain attributesand features of the designated critical habitat area that are grouped as“constituent elements,” including:Dens and/or denning habitat that provides shelter during the summer andwinter months;Vegetation that provides cover for the New Mexican ridge-nosed rattlesnakeand habitat for prey;NewMexicanridge-nosedrattlesnakeAbundance of prey (lizards and rodents)YesNo direct effects based on survival to the NewMexican ridge-nosed rattlesnake are expectedto occur (see Section 5.1.1.a. RQs of 0.018 fora 50 gram snake and RQ of 0.030 for a 500gram snake. Neither of these RQs exceeds theLOC of 0.1). However, growth andreproductive effects cannot be precluded due tothe absence of chronic data. Indirect effectsfrom a loss of the prey base are also expectedbecause effects to individuals withinpopulations have been demonstrated inmammals, birds, and invertebrates. Noindirect effects from habitat loss are expectedbecause this species does not appear to useBTPD burrows.PCEs were not described for the gray wolf. However, key habitatcomponents were described in the recovery plan:A year-round abundance of ungulate prey and alternate prey,Secluded and suitable denning and rendezvous sites, andGray wolfSufficient space with low human disturbance.YesDirect effects to the graywolf are expected tooccur based on the potential for this species toconsume prey items that have consumed thechlorophacninone bait (RQ of 24.82 forexposure to non-target animals and RQ of 9.59for exposure to BTPDs both of which exceedthe LOC of 0.1). Growth and reproductiveeffects cannot be precluded due to the absenceof chronic data; however, growth andreproductive effects arenot expected becausemortality typically occurs as a result of acuteexposure. Indirect effects from the loss of theprey base are also expected because effects toindividuals within populations have beendemonstrated in mammals, birds, andinvertebrates. No indirect effects from habitatloss are expected becausethis species does notuse BTPD burrows.97

### Following a preliminary MA determination, additiona l information is considered to refine the potential for exposure at the predicted levels based on the life history characteristics ( i.e ., habitat range, feeding preferences, etc .) of the assessed species. Based on the best available information, the Agency uses the refined evalua tion to distinguish those actions that MA -

NLAA from those actions that are MA - LAA th e assessed species and it s designated critical

habitat.

The criteria used to make determinations that the effects of an ac tion are NLAA the assessed species or modify its designated criti cal habitat include the following:

• Significance of Effect : Insignificant effects are those that cannot be meaningfully measured, detected, or evaluated in the contex t of a level of effect where “take” occurs for even a single individual. “Take” in this context means to harass or harm, defined as the following:

 Harm includes significant habitat modificat ion or degradation that results in death or injury to listed species by significantly impairing behavioral patterns such as breeding, feeding, or sheltering.

 Harass is defined as actions that create the likelihood of injury to listed species to such an extent as to significantly disrupt normal behavior patterns which include, but are not limited to, br eeding, feeding, or sheltering.

• Likelihood of the Effect Occurring : Discountable effects are those that are extremely unlikely to occur.

• Adverse Nature of Effect : Effects that are wholly benefi cial without any adverse effects

are not considered adverse.

A description of the risk and effects determin ations for each of the established assessment endpoints for the listed species th at may be affected and their designated critical habitat is provided in Sections 5.2.1 through 5.2.3 . The effects determinati on section will start with a discussion of the potential for dir ect effects, followed by a discussi on of the potential for indirect effects. These discussions consider the spatial analysis. For those listed species that have designated critical habitat, the section will end with a discussion on the potential for modification

to the critical habitat from the use of ch lorophacinone to control BTPDs. Finally, in Section

5.2.3 , a discussion of any potential overlap between the area of concern and the species that may be affected (including any designate d critical habitat) is presented. If there is no overlap or the counties with/containing the specie s’ habitat are not adjacent to the use area/BTPD habitat a NE

determination is made.

5.2.1. Direct Effects to Listed Species

Those species that may be affected through dir ect effects are those with RQs that exceed the acute listed species LOC of 0.1. All species ( i.e. birds and mammals) that have the potential to consume chlorophacinone bait or chlorophacinone poisoned animals smaller than a prairie dog have RQs that exceed this LOC. Additionally, mammals that have the potential to consume chlorophacinone poisoned prairie dogs or larger granivorous prey items have RQs that exceed the acute listed species LOC. All of the 21 listed sp ecies are expected to have direct effects. The New Mexican ridge-nosed rattlesnak e is the only species that is not expected to have direct

98

### effects based on survival; however , growth and reproductive effect s to this species cannot be precluded in the absence of chronic data. Furthe rmore, direct effects to invertebrates based on reproductive effects are expected resulting in direct effects to the American burying beetle and the Salt Creek tiger beetle.

5.2.1.a. Grizzly Bear

The use of chlorophacinone to control BTPDs is LAA the grizzly bear because the RQ for exposure to chlorophacinone bait (75.42) exceeds th e LOC (0.1) and significant exposure is likely to occur. The range of this species over laps with the action area (BTPD habitat). Rozol Prairie Dog Bait application season for control of BTPDs overlaps periods during which grizzly

bears are active and not hiberna ting. Although grizzly bears will be hibernating during most of this time. Chlorophacinone can be applied be tween October 1 and March 15 or spring green-up,

whichever occurs later. Gr izzly bears typically enter hi bernation between October and December and exit their dens at some point be tween March and May. A single day exposure to chlorophacinone bait or prey items exposed to ch lorophacinone bait is likely because grizzly bears range over very large areas (1,000 to 1,500 mi 2 

### ) that can include prairie dog towns and will feed opportunistically on ite ms including chlorophacinone poisoned prey items or chlorophacinone bait. A grizzly bear would only need to consume 4 grams of bait to reach the

LOC 11 

### . If a grizzly bear encounters an area where chlorophacinone is applie d, it is highly likely

that at least this amount of bait would be consum ed. A grizzly bear is mo st likely to encounter a Rozol application area shortly befo re or after hibernation at which time the bear is engorging itself. This only increases the like lihood that the bait would be consumed.

5.2.1.b. American Burying Beetle

The use of chlorophacinone to control BTPDs is LAA the American burying beetle based on direct reproductive effects. The reproductive effects are due to lower carcass size in chlorophacinone treated carcasses and effects to larvae. An acute t oxicity test for the earthworm (MRID 47383002) and an open literature study (Fisher et al. 2007) indicate that there is no risk to invertebrates at exposure levels relevant to this use. Furt hermore, the second phase of the burying beetle study (MRID 47383001 ) 

### that showed reproductive effects to burying beetles based on lower carcass weights showed that there were no direct acute effects to adult burying beetles fed chlorophacinone trea ted ground beef. In fact, those exposed to the chlorophacinone faired better than the control group.

Chlorophacinone use is expected to affect repr oduction of the American burying beetle through effects to emerged beetles. Number of emer ged beetles is negatively affected by use of chlorophacinone poisoned carcasses in burying beet les (MRID 47383001). This type of effect is

considered to be a direct effect.

11 RQ for bait consumption = 75.42; dry weight ingestion rate = 3,077 g/day; Acute Listed Species LOC = 0.1. (3,077 g/day)/( 75.42)*0.1 = 4 g/day



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### 5.2.1.c. Salt Creek Tiger Beetle

The use of chlorophacinone to control BTPDs is LAA the Salt Creek tiger beetle based on direct reproductive effects. The reproductive effects ar e due to lower carcass size in chlorophacinone

treated carcasses and effects to larvae. An acute toxicity test for the earthworm (MRID 47383002) and an open litera ture study (Fisher et al. 2007) indicate that there is no risk to invertebrates at exposure levels relevant to this use. Furthe rmore, the second phase of the burying beetle study (MRID 47383001 ) 

### that showed reproductive effects to burying beetles based on lower carcass weights showed that there were no direct acute effects to adult burying beetles fed chlorophacinone trea ted ground beef. In fact, those exposed to the chlorophacinone faired better than the control group.

Chlorophacinone use is expected to affect repr oduction of the Salt Creek tiger beetle through effects to emerged beetles. Number of emer ged beetles is negatively affected by use of chlorophacinone poisoned carcasses in bur ying beetles (MRID 47383001). Exposure can potentially occur in the larval stage through chlorophacinone insect residues. This type of effect

is considered to be a direct effect.

5.2.1.d. California Condor

The use of chlorophacinone to control BTPDs is LAA the California condor. California condors

are known to occur in four counties in Arizona as well as several counties in California. One of

the four counties in Arizona where the Califor nia condor is known to occur, Apache County, is adjacent to a county in New Mexico in which BT PDs are known to occur, Catron County. It is

conceivable since California condo rs are wide ranging species that they may prey on animals in an adjacent county. Although Ca lifornia condors typically prey on the carcasses of large mammals (cattle, sheep, deer, horses) they also have been known to prey on ground squirrels and other small to medium sized prey including coyote s, rabbits, foxes, weasels, rats, and pocket gophers. The California condor would have to consume 34 poisoned mice or almost two BTPDs every day for five days to reach the LOC 12 

### . Although consumption of 34 mice by a California condor is not likely, consumption of other exposed non-target gran ivores is more likely and can result in similar exposure. Additionally, cons umption of two BTPD carcasses is likely if the condor finds a Rozol Prairie Dog Bait application site. Furthermore, effects including external bleeding, internal hemorrhaging and increased bl ood coagulation time were seen in secondary exposure studies to birds. Previous assessments have considered thes e effects analogous to lethality thereby supporting this LAA determinat ion. Finally, growth a nd reproductive effects cannot be precluded due to th e absence of chronic data.

5.2.1.e. Whooping Crane

The use of chlorophacinone to control BTPDs is LAA the whooping crane. Rozol Prairie Dog Bait application season for the cont rol of BTPDs overlaps, spatially and temporally, with the fall

12 RQ for non-target animal consumption = 0.104; RQ for BTPD consumption = 0.04; wet weight ingestion rate = 709 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(709 g/day)/( RQ)*0.1]/[prey weight] = 34.2 mice or 1.8 BTPDs



### 100

### migration of the Aransas Wood Buffalo Population. Whooping cran es will eat wast e agricultural grains during their migrati on, and therefore it can be e xpected that the grain-based chlorophacinone bait (on or close to the surface) would be cons umed as well. The RQ for consumption of chlorophacinone grain bait (0.89) exceeds the LOC for endangered species (0.1). A whooping crane would need to eat 26 grams of bait to reach the LOC 13 

### . This is possible as the whooping crane’s ingestion rate (in gram s dry weight/day) is 227 g/day. The LC 50 

### on which this RQ is based is from a five day feeding study. Whooping cranes are likely to be migrating when they are exposed to chlorophacinone bait,. Duri ng migration, the cranes engorge themselves when they have the opportunity to feed. This onl y increases the likelihood that the bait will be consumed. According to the life history inform ation whooping cranes also consume rodents. It was determined that a whooping crane would have to eat 23 poisoned mice or more than one poisoned BTPD every day for five days to reach the LOC 14 

### . This is possible based on the life history information. It is po ssible that the whooping crane coul d eat 23 mice per day. However, it seems unlikely that the whooping crane woul d eat more than one BTPD every day. Furthermore, effects including external blee ding, internal hemorrhaging and increased blood coagulation time were seen in secondary exposure studies to birds. Previous assessments have considered these effects analogous to lethalit y thereby supporting this LAA determination. Finally, reproductive effects ca nnot be precluded based on th e absence of chronic data.

5.2.1.f. Eskimo Curlew

The use of chlorophacinone to control BTPDs is LAA the Eskimo curlew. The range of this species overlaps with BTPD habitat. Eskimo curlews prey on invertebrates which may be exposed to chlorophacinone bait. This a ssessment assumes invertebrates exposed to chlorophacinone will have the same maximum resi due concentration as the deer mouse (5.8 mg a.i./kg-bw). The curlew would have to cons ume 149 grams of poisoned invertebrates every day for five days to reach the LOC 15 

### . The curlew’s ingestion rate is 155 g/day. Given this, it is possible that the Eskimo curlew would be exposed at levels exceeding the LOC. Furthermore, effects including external bleeding, internal hemorrhaging and increased blood coagulation time were seen in secondary exposure studies to birds. Previous as sessments have considered these effects analogous to lethality thereby supporting this LAA dete rmination. Finally, reproductive effects cannot be precluded based on the absence of chronic data.

5.2.1.g. Northern Aplomado Falcon

The use of chlorophacinone to control BTPDs is LAA the northern Aplomado falcon. The range of this species overlaps with BTPD habitat. Northern Aplomado falcons prey on birds and rodents which may be exposed to chlorophacinone bait. The falcon would have to consume 5

13 RQ for bait consumption = 0.89; dry weight ingestion rate = 227 g/day; Acute Listed Species LOC = 0.1. (227 g/day)/( 0.89)*0.1 = 25.5 g/day

14 RQ for non-target animal consumption = 0.104; RQ for BTPD consumption = 0.04; wet weight ingestion rate = 470 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(470 g/day)/( RQ)*0.1]/[prey weight] = 22.6 mice or 1.2 BTPDs

15 RQ for invertebrate consumption = 0.104; wet weight ingestion rate = 155 g/day; Acute Listed Species LOC = 0.1. (155 g/day)/(0.104)*0.1 = 149 g/day



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### poisoned mice or less than one BTPD to reach the LOC 16 

### . According to life history information the average weight of th eir preferred prey (birds) is around 67 grams. The majority of the birds weighed less than 100 grams. However, falcons are capable of taking larger prey with weights around 300-570 grams. Based on this information it seems unlikely but possible that a falcon would prey on a prairie dog but th ey may consume mice. Given th is, it is possible that the northern Aplomado falcon would be exposed at leve ls exceeding the LOC. Furthermore, effects including external bleeding, in ternal hemorrhaging and increa sed blood coagulation time were seen in secondary exposure studies to birds. Previous assessments have considered these effects analogous to lethality thereby supporting this LA A determination. Finally, reproductive effects cannot be precluded based on the absence of chronic data.

5.2.1.h. Black Footed Ferret

The use of chlorophacinone to control BTPDs is LAA black footed ferrets. The black footed ferret RQs (7.45 for exposure to BTPDs and 19.29 fo r exposure to non-target animals) exceed the LOC for endangered species (0.1). Exposure is likely considering the black footed ferret predominantly preys on prairie dogs. The Rozo l Prairie Dog Bait label indicates that the “product [is not to be used] within prairie dog towns in the range of the black-footed ferret without first contacting endangere d species specialists at a U.S. Fish and Wildlife Service.” However, if chlorophacinone was used in a BTPD town near black-footed ferrets there would be

direct effects to the black-footed ferret. The bl ack-footed ferret would need to eat less than one poisoned BTPD or one poisoned mouse to reach the LOC 17



### .

5.2.1.i. Chiricahua Leopard Frog

The use of chlorophacinone to control BTPDs is LAA the Chiricahua leopard frog. The range of this species overlaps with BTPD habitat. Chir icahua leopard frog prey on invertebrates which may be exposed to chlorophacinone bait. Th is assessment assumes many types of insects exposed to chlorophacinone will have the same maximum residue concentration as the deer mouse (5.8 mg a.i./kg-bw). The Chiricahua le opard frog would have to consume 78 grams of poisoned invertebrates every day for five days to reach the LOC 18 

### . The Chiricahua leopard frog’s ingestion rate is 81 g/day. Given this, it is possible that the Chir icahua leopard frog would be exposed at levels exceeding the LOC. Fu rthermore, effects including external bleeding, internal hemorrhaging and increased blood coagul ation time were seen in secondary exposure

studies to birds. Previous assessments have considered these effects analogous to lethality thereby supporting this LAA determination. Fi nally, reproductive effect s cannot be precluded based on the absence of chronic data. Herptiles ar e assessed using avian toxi city data; therefore, these results are relevant to the Chiricahua leopard frog.

16 RQ for non-target animal consumption = 0.104; RQ for BTPD consumption = 0.04; wet weight ingestion rate = 102 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(102 g/day)/( RQ)*0.1]/[prey weight] = 4.9 mice or 0.3 BTPDs

17 RQ for non-target animal consumption = 19.29; RQ for BTPD consumption = 7.45; wet weight ingestion rate = 147.84 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(148 g/day)/( RQ)*0.1]/[prey weight] = 0.04 mice or 0.002 BTPDs

18 RQ for invertebrate consumption = 0.104; wet weight ingestion rate = 81 g/day; Acute Listed Species LOC = 0.1. (81 g/day)/(0.104)*0.1 = 78 g/day



### 102

### 5.2.1.j. Jaguar

The use of chlorophacinone to control BTPDs is LAA the jaguar. Jaguars are known to occur in

three counties in Arizona as we ll as one county in New Mexico. The county in New Mexico, Hidalgo County, where the jaguar is known to o ccur is also a county in which BTPDs are known to occur. Although jaguars typically prey on javelin a (a wild boar), deer, a nd livestock, they also have been known to prey on large rodents in cluding capybaras and paca as well as armadillos and caimans. They have also been known to take various species of turt les, birds, and fish. Thus, although it is unlikely, it is possible that a jaguar might take a poisoned BTPD. The jaguar would have to consume less than one poisoned m ouse or less than one poisoned BTPD every day for five days to reach the LOC 19 

### . Although there is evidence in th e life history that they forage on rodents, the rodents that they tend to consume are mu ch larger than a BTPD ( e.g. capybara and paca, both weighing more than 20 pounds). However, it is possible that a jaguar could consume poisoned BTPDs. Although, it seems un likely that a jaguar would feed on a BTPD every day for a five day period, if a jaguar en countered a chlorophacinone poisoned BTPD town, consumption at this level could possibly occur.

5.2.1.k. Gulf Coast Jaguarundi

The use of chlorophacinone to control BTPDs is LAA the Gulf Coast jaguarundi. The Gulf Coast jaguarundi occurs in the so uthern part of Texas but is kn own to occur in counties as far north in Texas as Atascosa County. Atascosa County is adjacent to Bexar County, Texas in

which BTPDs are known to occur. It is conceiva ble that the Gulf Coast jaguarundi may prey on animals in an adjacent county. Jaguarundis typically prey on small mammals, birds, and reptiles.

Stomach contents have included: lizards, rodents (mice and rats ), small birds, and cottontail rabbits, and grass. The Gulf Coast jaguarundi would have to consume less than one poisoned mouse or less than one poisoned BTPD every day for five days to reach the LOC 20



### . Consumption at this level could reasonably occur.

5.2.1.l. Canada Lynx

The use of chlorophacinone to control BTPDs is LAA the Canada lynx. The range of this species overlaps with BTPD habitat. Canada ly nx typically prey on the snowshow hare but have also been known to prey opportunistically on sma ll mammals and birds. Other prey may include rodents and fish and lynx may also prey on ungul ates. The Canada lynx would have to consume less than one poisoned mouse or less than one po isoned BTPD every day for five days to reach

the LOC 21 

### . There is evidence in the life history that the Canada lynx forages on small to

19 RQ for non-target animal consumption = 32.85; RQ for BTPD consumption = 12.69; wet weight ingestion rate = 4119 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(4119 g/day)/( RQ)*0.1]/[prey weight] = 0.6 mice or 0.03 BTPDs

20 RQ for non-target animal consumption = 23.82; RQ for BTPD consumption = 9.2; wet weight ingestion rate = 739 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(739 g/day)/( RQ)*0.1]/[prey weight] = 0.2 mice or 0.008 BTPDs

21 RQ for non-target animal consumption = 23.3; RQ for BTPD consumption = 9.0; wet weight ingestion rate = 819 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(819 g/day)/( RQ)*0.1]/[prey weight] = 0.2 mice or 0.009 BTPDs



### 103

### medium size prey and further it seems possible th at they could consume one BTPD every day

five da for

ys.

5.2.1.m. Preble’s Meadow Jumping Mouse

The use of chlorophacinone to control BTPDs is LAA the Preble’s meadow jumping mouse. The range of this species overlaps with BTPD ha bitat. Rozol Prairie Dog Bait application season for the control for BTPDs overlaps periods during which the Preble’s meadow jumping mouse is active and not hibernating. However, Preble’s meadow jumping mice will be hibernating during most of this time. Chlorophacinone can be a pplied between October 1 and March 15 or spring green-up, whichever occurs later. Preble’s m eadow jumping mice typical ly enter hibernation between late August and October and come out of hibernation in May. Ba sed on the life history

information it seems reasonable that the Preble’s meadow jumping mouse could be exposed to the chlorophacinone bait. A Preb le’s meadow jumping mouse would have to eat less than one grain of Rozol Prairie Dog Bait per da y for five days to reach the LOC 22 

### . It is possible that a Preble’s meadow jumping mouse could consume this amount of bait. The Preble’s meadow jumping mouse is most likely to encounter a Rozol application area shortly before or after hibernation at which time the mouse is engorging itself. This only incr eases the likelihood that

the bait would be consumed.

5.2.1.n. Ocelot

The use of chlorophacinone to control BTPDs is LAA the ocelot. The ocelot occurs in the southern part of Texas but is known to occur in counties as far north in Texas as Atascosa County. Atascosa County is adjacent to Bexar County, Texas in which BTPDs are known to

occur. It is conceivable since the ocelot is a wide ranging species that they may prey on animals in an adjacent county. Ocelot s typically prey on small to medium-sized mammals (rabbits, agoutis, and mice), birds, reptiles (snakes and lizards), fish, and invertebrates. Ocelots would have to consume less than one poisoned mouse or less than one poisoned BTPD every day for five days to reach the LOC 23 

### . There is evidence in the life history that they forage on mice and if it were intoxicated and easily captured, a BTPD coul d be a prey item as well. It is possible that they would consume a mouse or BTPD every day for five days.

5.2.1.o. Mexican Spotted Owl

The use of chlorophacinone to control BTPDs is LAA the Mexican spotted owl. The range of this species overlaps with the BTPD habitat. Me xican spotted owls typically prey on small- and medium-sized rodents including wo odrats, peromyscid mice, and microtine voles. They also eat bats, birds, reptiles, and arthropods. The Mexi can spotted owl would have to consume almost

22 RQ for bait consumption = 41.35; dry weight ingestion rate = 1.94 g/day; mass of one grain = 0.2 g; Acute Listed Species LOC = 0.1; [(1.94 g/day)/(41.35)*0.1]/(0.2 g) = 0.02 grain

23 RQ for non-target animal consumption = 26.96; RQ for BTPD consumption = 10.41; wet weight ingestion rate = 1576 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(1576 g/day)/( RQ)*0.1]/[prey weight] = 0.3 mice or 0.02 BTPDs



### 104

### six poisoned mice or less than one poisoned BTPD every day for five days to reach the LOC 24



### . There is evidence in the life history that they forage on small to medium size prey. However, based on the Mexican spotted owl’s ingestion rate (41 g/day), it seems un likely that they would consume 20 mice or one BTPD every day for five days. Nonetheless, la cking avian reproduction data, risk cannot be precluded at any dose level. Furthermor e, effects including external bleeding, internal hemorrhaging and increased bl ood coagulation time were seen in secondary exposure studies to birds. Previous assessments have considered thes e effects analogous to lethality thereby supporting this LAA determination.

5.2.1.p. Piping Plover

The use of chlorophacinone to control BTPDs is LAA the piping plover. The range of this species overlaps with BTPD habitat. Piping pl over prey on invertebrates which may be exposed to chlorophacinone bait. This assessment assume s invertebrates exposed to chlorophacinone will

have the same maximum residue concentration as the deer mouse (5.8 mg a.i./kg-bw). The piping plover would have to cons ume 44 grams of poisoned inverteb rates every day for five days

to reach the LOC 25 

### . The piping plover’s ingestion rate is 46 g/day. Given this, it is possible that the piping plover would be exposed at levels exceeding the LOC. Furthermore, effects including external bleeding, internal hemo rrhaging and increased blood coagulation time were seen in secondary exposure studies to bi rds. Previous assessments ha ve considered these effects analogous to lethality thereby supporting this LA A determination. Finally, reproductive effects cannot be precluded at any exposure level in the absence of chronic data.

5.2.1.q. New Mexican Ridge-nosed Rattlesnake

The use of chlorophacinone to control BTPDs is LAA the New Mexican ridge -nosed rattlesnake. The RQ does not exceed the LOC for the Ne w Mexican ridge-nosed rattlesnake. See Section

5.1.1.a above for the rationale. However, direct growth and reproductive effects cannot be precluded in the absence of avian reproduction da ta. Furthermore, effects including external bleeding, internal hemorrhaging and increased bl ood coagulation time were seen in secondary exposure studies to birds. Previous assessments have considered thes e effects analogous to lethality thereby supporting this LAA determinati on. Herptiles are assesse d using avian toxicity data, therefore, these results are relevant to the New Mexican ridge-nosed rattlesnake.

5.2.1.r. Sonora Tiger Salamander

The use of chlorophacinone to control BTPDs is LAA the Sonora tiger salamander. The range of this species is adjacent to the BTPD habitat. Sonora tiger salamanders are known to occur in two counties in Arizona (Cochise and Santa Cruz co unties). One of the two counties in Arizona where the Sonora tiger salamander is known to occu r, Cochise County, is adjacent to a county in

New Mexico in which BTPDs are known to o ccur, Hidalgo County. Metamorphosed Sonora

24 RQ for non-target animal consumption = 0.104; RQ for BTPD consumption = 0.04; wet weight ingestion rate = 118 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(118 g/day)/( RQ)*0.1]/[prey weight] = 5.6 mice or 0.4 BTPDs

25 RQ for invertebrate consumption = 0.104; wet weight ingestion rate = 46 g/day; Acute Listed Species LOC = 0.1. (46 g/day)/(0.104)*0.1 = 44 g/day



### 105

### tiger salamanders prey on terrestrial insects and other macroinvertebrates which may be exposed to chlorophacinone bait. This assessment assumes invertebrates exposed to chlorophacinone will

have the same maximum residue concentration as the deer mouse (5.8 mg a.i./kg-bw). The Sonora tiger salamander would have to consume 50 grams of poisoned invertebrates every day for five days to reach the LOC 26 

### . The Sonora tiger salamander’s ingestion rate is 52 g/day. Given this, it is possible that the Sonora tiger salamander would be exposed at levels exceeding the LOC. Lacking avian reproduction data, risk cannot be precluded at any dose level. Furthermore, effects including external blee ding, internal hemorrhaging and increased blood coagulation time were seen in secondary exposure studies to birds. Previous assessments have considered these effects analogous to lethalit y thereby supporting this LAA determination. Herptiles are assessed using avian toxicity data; therefore, these results are re levant to the Sonora tiger salamander.

5.2.1.s. Black-capped Vireo

The use of chlorophacinone to control BTPDs is LAA the black-capped vireo. The range of this species overlaps with BTPD habitat. Black-capped vireos prey on invertebrates, primarily beetles and caterpillars, whic h may be exposed to chlorophacinone bait. This assessment assumes invertebrates exposed to chlorophacinone will have the same maximum residue

concentration as the deer mous e (5.8 mg a.i./kg-bw). The black-capped vireo would have to consume 16.3 grams of poisoned invertebrates every day for five days to reach the LOC 27 

### . The black-capped vireo’s ingestion rate is 16.9 g/day. Given this, it is possible that the black-capped vireo would be exposed at levels exceeding the LOC. Furthermor e, effects including external bleeding, internal hemorrhaging and increased bl ood coagulation time were seen in secondary exposure studies to birds. Previous assessments have considered thes e effects analogous to lethality thereby supporting this LAA determin ation. Finally, reproductive effects cannot be precluded at any exposure level in the absence of chronic data.

5.2.1.t. Golden-Cheeked Warbler

The use of chlorophacinone to control BTPDs is LAA the golden-cheeked warbler. The range of this species overlaps with BTPD habitat. Gold en-cheeked warblers prey on invertebrates ( e.g. insects, spiders and caterpillars) which may be exposed to chlorophacinone bait. This assessment assumes invertebrates exposed to chlorophacinone will have the same maximum

residue concentration as the deer mouse (5.8 mg a.i./kg-bw). The golden-cheeked warbler would have to consume 17.4 grams of poisoned inverteb rates every day for five days to reach the

LOC 28 

### . The golden-cheeked warbler’s ingestion rate is 18.1 g/day. Gi ven this, it is possible that the golden-cheeked warbler would be exposed at levels exceeding the LOC. Lacking avian reproduction data, risk cannot be precluded at any dose level. Furthermore, effects including external bleeding, internal hemo rrhaging and increased blood coagulation time were seen in

26 RQ for invertebrate consumption = 0.104; wet weight ingestion rate = 52 g/day; Acute Listed Species LOC = 0.1. (52 g/day)/(0.104)*0.1 = 50 g/day

27 RQ for invertebrate consumption = 0.104; wet weight ingestion rate = 16.9 g/day; Acute Listed Species LOC = 0.1. (16.9 g/day)/(0.104)*0.1 = 16.3 g/day

28 RQ for invertebrate consumption = 0.104; wet weight ingestion rate = 18.1 g/day; Acute Listed Species LOC = 0.1. (16.9 g/day)/(0.104)*0.1 = 17.4 g/day



### 106

### secondary exposure studies to bi rds. Previous assessments ha ve considered these effects analogous to lethality thereby s upporting this LAA determination.

5.2.1.u. Gray Wolf

The use of chlorophacinone to control BTPDs is L AA the gray wolf. The range of this species overlaps with the BTPD habitat. Although gray wo lves typically prey on white-tailed deer, mule deer, moose, elk, caribou, bison, muskox, bighorn sheep, Dall sheep, mountain goat, beaver, and snowshoe hare. Small mammals, birds, and larg e invertebrates are sometimes also taken. The gray wolf would have to consume less than one poisoned mouse or less than one poisoned BTPD every day for five days to reach the LOC 29 

### . There is evidence in th e life history that the gray wolf forages on small to medium size prey and fu rther it seems possible th at they could consume mice and/or BTPDs over a five day period.

5.2.2. Indirect Effects to Listed Species

The use of chlorophacinone to control BTPDs is LAA the grizzly bear, Am erican burying beetle, whooping crane, Eskimo curlew, northern Aplo mado falcon, black-footed ferret, Chiricahua leopard frog, Preble’s meadow jumping mouse, New Mexican ridge-nosed rattlesnake, and the gray wolf with respect to indir ect effects. The potential for indi rect effects comes from loss of prey base (BTPDs or other exposed non-target animal populations) and loss of habitat (BTPD burrows).

Grizzly bears, American burying beetles, whoopi ng cranes, northern Aplomado falcons, blackfooted ferrets, Chiricahua leopard frog, New Mexi can ridge-nosed rattlesnakes, and gray wolves have potential to prey upon BTPDs and/or other non-target exposed mammals affected by chlorophacinone. Effects to individuals have be en demonstrated in mammals ranging in size from 13 g to 36,363 g with RQs ranging from 19 to 41. The Agency does not currently have a method to extrapolate risk from individuals to a prey-base level effect. In the absence of this level of analysis, risk cannot be precluded and effects to mammalian prey bases are presumed. For this prey-base level e ffect, use of chlorophacinone to control BTPDs is LAA.

American burying beetles, whooping cranes, no rthern Aplomado falcons, black-footed ferrets, New Mexican ridge-nosed rattlesnakes, and gray wolves have potential to prey upon birds or herptiles affected by chlorophaci none. The diet based RQ for birds consuming chlorophacinone bait is 0.89. This RQ exceeds the endangered species Acute Risk LOC and effects to individuals are, therefore, expected. The Agency does not cu rrently have a method to extrapolate risk from individuals to a prey-base level effect. In the absence of this level of analysis, risk cannot be precluded and effects to avian a nd herptile prey bases are presum ed. For this prey-base level effect, use of chlorophacinone to control BTPDs is LAA.

29 RQ for non-target animal consumption = 24.82; RQ for BTPD consumption = 9.59; wet weight ingestion rate = 2311 g/day; BTPD weight = 1000 g; mouse weight = 20 g; Acute Listed Species LOC = 0.1. [(2311 g/day)/( RQ)*0.1]/[prey weight] = 0.5 mice or 0.02 BTPDs



### 107

### Those species that consume invertebrates ( i.e. American burying beetle, whooping crane, Eskimo curlew, northern Aplomado falcon, black-foot ed ferret, Chiricahua leopard frog, Preble’s meadow jumping mouse, New Mexican ridge-nosed rattlensnake, and the gray wolf) may have

indirect effects from a loss of their invertebra te prey base because larvae consuming chlorophacinone residues have reproductive effects (MRID 47383001). The Agency does not currently have a method to extrapolate risk from individuals to a prey-bas e level effect. In the absence of this level of analysis, risk cannot be precluded and effects to invertebrate prey bases are presumed. For this prey-base level effect, use of chlorophacinone to control BTPDs is LAA.

There are indirect effects to the black footed ferret due to habitat (burrow) loss. The blackfooted ferret is a prairie dog obligate species (USFWS, 1988). It ha s been known to take advantage of prairie dog burrows for shelter and travel, and “may modify prairie dog burrows for its own use” (Nowak, 1999).

5.2.3. Modification of Designated Critical Habitat

5.2.3.a. Potential Areas of MA Effect - Overlap or Adjacent BTPD Habitat and Occurrence of the Assessed Listed Species

This assessment analyzes the use of chlorophacinone grain bait to control BTPDs. As a result, the action area was identified as the range of th e BTPD obtained from Natu reServe. The initial

area of concern is defined as all land cove r types within the range of the BTPD. Appendix A provides an overview of where the action area ov erlaps with species range as described in

Section 2.5 . Only species with habitat that overlappe d or were found in adjacent counties (direct effects only) with the BTPD hab itat were included in this assessment. For habitat modification and prey base effects, adjacent counties were not considered.

Pesticide exposures and predicted risks to the species and its res ources (i.e., food and habitat) are not expected to be uniform across the action area since BTPDs are not uniformly distributed

across action area.

5.3. Effects Determinations Summary

The Agency makes a may affect, and likely to adversely affect determination for the grizzly bear, American burying beetle, Sa lt Creek tiger beetle, whooping cr ane, Eskimo curlew, northern Aplomado falcon, black-footed ferret, Chirichaua leopard frog, jaguar, Gulf Coast jaguarundi, Canada lynx, Preble’s meadow jumping mouse, ocelot, Mexican spotted owl, piping plover, New Mexican ridge-nosed rattlesnake, Sonora tiger sa lamander, black-capped vireo, golden-cheeked warbler, and the gray wolf and a habitat modification determination for the Salt Creek tiger beetle, whooping crane, Canada l ynx, Preble’s meadow jumping mouse, Mexican spotted owl, piping plover, and New Mexican ri dge-nosed rattlesnake. The Ca lifornia condor and gray wolf are not included in the list of species for whic h habitat modification was determined because the critical habitat for these species do not overlap with the BTPD range.

108

### 5.3.1. Addressing the Risk Hypotheses

In order to conclude this risk assessment, it is necessary to ad dress the risk hypotheses defined in

Section 2.9.1 . Based on the conclusions of this a ssessment, all four hypotheses represent

concerns in terms of direct and indirect effect s of chlorophacinone on some of the listed assessed species and their designated critical habitat.

The labeled use of chlorophacinone fo r BTPDs within the action area will:

• directly affect listed species by causing mortality or by adversely affecting growth or reproduction through primary exposure to/consumption of chlorophacinone bait;

• directly affect listed species by causing mortality or by adversely affecting growth or reproduction through secondary exposure to chlorophacinone poisoned animals, BTPDs and other non-target anim als, and/or carcasses.

• indirectly affect listed species and/or modify their designate d critical habitat by reducing or changing the composition of their food supply;

• indirectly affect listed species and/or modify their designate d critical habitat by reducing populations of BTPDs which provide burrows for shelter

6. Uncertainties

This section describes uncertainties specific to this assessment.

6.1. Exposure Assessment Uncertainties

6.1.1. Maximum Use Scenario

The screening-level risk assessment focuses on char acterizing potential ec ological risks resulting from a maximum use scenario, which is determ ined from labeled statements of maximum application rate and number of applications with th e shortest time interval between applications. The frequency at which actual uses approach th is maximum use scenario may be dependant on pest resistance, timing of applications, cultural practices, and market forces.

6.1.2. Usage Uncertainties

Usage data is unavailable for chlorophacinone t hough anecdotal evidence and the breadth of the registrant’s advertising campaign indicate that use is highly prev alent. Uncertainty regarding intensity of chlorophacinone use affects exposure to species of concern with expansive ranges ( e.g. grizzly bear, California condor, whooping cran e, jaguar, Gulf Coast jaguarundi, Canada lynx, piping plover, ocelot, black-c apped vireo, golden-cheeked warb ler, and the gray wolf). Whether chlorophacinone is used on one prairie d og town within a given animal’s range or many will influence the probability that the animal is affected. To account for this uncertainty, RQs

109

### are based on a food intake of 100% chlorophacinone grain bait and/or chlorophacinone-poisoned

carcasses.

6.2. Effects Assessment Uncertainties

6.2.1. Data Gaps and Uncertainties

Data gaps include:

• Avian reproduction study for ch lorophacinone (guideline 850.2300).

• Terrestrial field study for use of chloroph acinone bait to control BTPDs (guideline 850.2500 in conjunction with pr otocol discussions).

Due to these data gaps, risk cannot be precl uded to birds and exposure cannot be fully

characterized.

6.2.2. Carcass Residue Concentration

All carcass residue concentration da ta discussed in this assessment is based on animals that have been fed chlorophacinone bait to mortality. Dete rmining residue concentrations at mortality does not necessarily capture the highest concentra tion. Metabolism of toxicants can continue for a period of time post-mortem, therefore, residue con centrations are likely hi ghest just prior to or

concurrent with animal mortalit y. Poisoned prey items are highly vulnerable to predation before succumbing to anticoagulant poisoning. Given th is, listed predators and scavengers may be exposed to higher residue concentrations than are reflected in carcass residue studies. To account for this uncertainty, the highest whole body concentration was used to characterize prairie dog chlorophacinone concentrations and th e highest relevant conc entration was used to

characterize residue concentrati ons in non-target granivores.

6.2.3. Sublethal Effects

When assessing acute risk, the screening risk a ssessment relies on the acute mortality endpoint as

well as a suite of sublethal res ponses to the pesticide, as dete rmined by the testing of species response to chronic exposure c onditions and subsequent chronic risk assessment. Consideration

of additional sublethal data in the effects determination is exer cised on a case-by-case basis and only after careful consideration of the nature of the sublethal eff ect measured and the extent and quality of available data to support establishing a plausible relationship between the measure of effect (sublethal endpoint) and the assessment endpoints. Howeve r, the full suite of sublethal effects from valid open literature studies is considered for characte rization purposes, including defining the action area.

Though no mortalities were reporte d in the raptor feeding studi es, sublethal effects were

indicated that could affect the likelihood of survival in the wil d. These sublethal effects were external bleeding, internal he morrhaging and increased blood coagulation time. Incidents involving a bald eagle, a ferruginous hawk, and a great horned ow l indicate the potential for

110

### chlorophacinone poisoning to cause mortality or contribute to mort ality of predatory birds.

Sublethal effects are also seen in mammals.

7. Risk Conclusions

In fulfilling its obligations under Section 7(a)(2) of the Endangere d Species Act, the information presented in this endangered spec ies risk assessment represents the best data currently available to assess the potential risks of chlorophacinone to the all listed species and their designated

critical habitat in the action ar ea for registered uses of Rozol Prairie Dog Bait (EPA registration number 7173-286).

Based on the best available information, the Agency makes a Likely to Adversely Affect determination for the following species: grizzly bear, American burying beetle, Salt Creek tiger beetle, California condor, whooping crane, Es kimo curlew, northern Aplomado falcon, blackfooted ferret, Chirichaua leopard frog, jaguar, Gulf Coast jaguarundi, Canada lynx, Preble’s meadow jumping mouse, ocelot, Mexican spotte d owl, piping plover, New Mexican ridge-nosed rattlesnake, Sonora tiger salamander, black-capped vireo, gold en-cheeked warbler, and the gray wolf from the use of chlorophacinone to c ontrol BTPDs. Additi onally, the Agency has determined that there is the potential for modification of habitat for the following species with designated critical habitat: Salt Creek tiger beetle, whooping crane, Canada lynx, Preble’s meadow jumping mouse, Mexican spotted owl, piping plover, and the New Mexican ridge-nosed

rattlesnake.

A summary of the risk conclusions and effects determinations fo r the listed species and their critical habitat, given the uncertainties discussed in Section 6 , is presented in Table 7.1 . and

Table 7.2.

111

### Table 7.1 Effects Determination Summary for Effects of Chlorophacinone to 21 Endangered Species.

Basis for Determination Species Effects

Determination Direct Effects Indirect Effects

Grizzly bear LAA 1 Direct effects are expected for the grizzly bear based on the potential for this species

to consume the chlo rophacinone bait (RQ of 75.42 which exceeds the LOC of 0.1) or other prey items that may have consumed the chlorophacinone bait (RQ of 3.38 for exposure to BTPDs and RQ of 8.75 for exposure to non-target animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute

exposure. Indirect effects from the loss of the prey base are also expected because

effects to individuals within populations have been demonstrated in mammals ranging in size from 13 to 36,363 grams with RQ ranging

from 19 to 41. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

American burying beetle LAA Reproductive effects are expected for the American burying beetle. The American burying beetle uses mammalian and avian carcasses as a food resource during their reproduction cycle. Dosed carcasses negatively affected number of emerged beetles (MRID 47383001). Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Salt creek tiger

beetle LAA Reproductive effects are expected for the Salt Creek tiger beetle. Salt Creek tiger beetle larvae are potentially exposed to chlorophacinone residues through chlorophacinone exposed terrestrial

invertebrates. Dosed carcasses in a burying beetle study negatively affected number of emerged beetles (MRID 47383001). Similar a ffects are expected for the Salt Creek tiger beetle. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. This species uses mud banks of streams and seeps in

association with saline wetlands and exposed mud flats of saline wetlands which is distinct from the short grass prairie associated w ith BTPD habitat.

No indirect effects from habitat loss are expected because this species

does not use BTPD burrows.

California

condor LAA Direct effects to the California condor are expected through thei r potential exposure to prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. No indirect effect s from the loss of prey base are expected because this species’ range does not overlap with the BTPD range. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Whooping crane LAA Direct effects to the whooping crane are expected to occur based on the potential for this species to consume the chlorophacinone bait (RQ of 0.89 which exceeds the LOC of 0.1) or other prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected



### 112exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. because this species does not use

BTPD burrows.

Eskimo curlew LAA Direct effects to the Eskimo curlew are expected to occur based on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of

chronic data. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated

in terrestrial invertebrates. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Northern Aplomado

falcon LAA Direct effects to the northern Aplomado falcon are expected through their potential exposure to prey items that may have

consumed the chlo rophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Black-footed

ferret LAA Direct effects are expected for the blackfooted ferret based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 7.45 for exposure to BTPDs and RQ of 19.29 for exposure to non-target animals, both which exceed the LOC of 0.1). Significant exposure is expected to occur because black-footed ferrets prey primarily on BTPDs. Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute

exposure. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial invertebrates. In addition, this species preys almost exclusively on

BTPDs. Indirect effects from habitat loss are expected because this species

uses BTPD burrows.

Chirichaua leopard frog LAA Direct effects to the Chirichaua leopard frog are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated

in terrestrial invertebrates and birds.

No indirect effects from habitat loss are expected because this species does not appear to use BTPD

burrows.

Jaguar LAA Direct effects are expected for the jaguar based on the potential for this species to consume prey items that may have

consumed the chlo rophacinone bait (RQ of 12.69 for exposure to BTPDs and RQ of 32.85 for exposure to non-target No indirect effect s from the loss of the prey base are expected because this species’ habitat is distinct from the BTPD habitat. Jaguars – particularly males of the northern reaches – are known to have large



### 113animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. home ranges that encompass a variety of plant communities,including: Maderan evergreenwoodland, subalpine conifer forest, semidesert shrubland, and Sonoran desert scrub. Washes and riparian areas with dense vegetative growth may also be valuable movement

corridors. These habitats are distinct from the short grass prairie

associated with BTPD habitat. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Gulf Coast jaguarundi LAA Direct effects are expected for the Gulf Coast jaguarundi based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 9.20 for exposure to BTPDsand RQ of 23.82 for exposure to nontarget animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. No indirect effect s from the loss of the prey base are expected because this species’ habitat is distinct from the BTPD habitat. This species is found in chaparral plant communities and dense brushy areas near streams

and rivers which are distinct from the short grass prairie associated with

BTPD habitat. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Canada lynx LAA Direct effects to the Canada lynx are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinonebait (RQ of 23.30 for exposure to nontarget animals and RQ of 9.00 for exposure to BTPDs both of which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. The Canada lynx is associated with the southern,

transitional reaches of the cool and

moist boreal forest. Where it occurs at these lower latitudes, the boreal

forest forms a mixed conifer and conifer-hardwood landscape. These

habitat areas are distinct from the short grass prairie associated with

BTPD habitat. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Preble’s

meadow jumping mouse LAA Direct effects to the Preble’s meadow jumping mouse are expected to occur based on the potential for this species to consume the chlorophacinone bait (RQ of 41.35 which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute

exposure. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in terrestrial invertebrates. Although this species makes nests both above and below ground. It does not appear to use other species’ burrows.

Ocelot LAA Direct effects are expected for the ocelot based on the potential for this species to No indirect effects from loss of prey base are expected because this



### 114consume prey items that have may

consumed the chlo rophacinone bait (RQ of 10.41 for exposure to BTPDs and RQ of 26.96 for exposure to non-target animals, both which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. species’ habitat is distinct from BTPD habitat. Ocelots appear to use areas of dense cover, and in the northern part of the range hunt in brushy forests and semi-arid deserts. In the southern part of its range, ocelot habitat includes tropical forests, mountain slopes, and pampas (grasslands). These habitat areas are distinct from the short grass prairie

associated with BTPD habitat. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Mexican spotted

owl LAA Direct effects to the Mexican spotted owl are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. Mexican spotted owls are found in old-growth or mature forests with unevenly aged stands of trees, high canopy, multi-storied levels, and high tree density as well as canyons with riparian or conifer

communities. In Arizona and New Mexico they are found in habitatsassociated with mixed conifer, pineoak, Arizona cypress, oak woodlands, and associated riparian

forests. These habitat areas are distinct from the short grass prairie

associated with BTPD habitat. No

indirect effects from habitat loss are expected because this species does

not use BTPD burrows.

Piping plover LAA Direct effects to the piping plover are expected to occur based on the potential for this species to consume prey items that may have consumed the chlorophacinonebait (RQ of 0.104 for exposure to nontarget animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded

due to the absence of chronic data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. The plover’s home range within BTPD range is usually limited to the wetland, lakeshore, or

section of beach where its nest is

located. No indirect effects from habitat loss are expected because this species does not use BTPD burrows.

New Mexican ridge-nosed

rattlesnake LAA No direct effects based on survival to the New Mexican ridge-nosed rattlesnake are expected to occur (see Section 5.1.1.a. RQs of 0.018 for a 50 gram snake and RQ of 0.030 for a 500 gram snake. Neither of these RQs exceeds the LOC of 0.1). However, growth and reproductive effects cannot be precluded due to the absence of

chronic data. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not appear

use BTPD burrows.

Sonora tiger

salamander LAA Direct effects to the Sonora tiger salamander are expected to occur based on the potential for this species to consume No indirect effect s from the loss of prey base or loss of habitat (BTPD burrow) are expected because this



### 115prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. species’ range does not overlap with BTPD range.

Black-capped

vireo LAA Direct effects to the black-capped vireo are expected to occur based on the potential for this species to consume prey

items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. Black-capped vireos

are found in mixed deciduous/evergreen shrub land. Breeding vireos use shrubby growth of irregular height and distribution with spaces the small thickets and clumps and with vegetative extending to ground level. These

habitat areas are distinct from the short grass prairie associated with

BTPD habitat. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

Golden-cheeked

warbler LAA Direct effects to the golden-cheeked warbler are expected to occur based on the potential for this species to consume prey

items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic

data. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from

BTPD habitat. Golden-cheeked

warblers are found in mixed Ashejuniper and oak woodlands in ravines and canyons. They spend summers in open canopy forest and winters in closed canopy forests. These habitat areas are distinct from the short grass prairie associated w ith BTPD habitat.

No indirect effects from habitat loss are expected because this species

does not use BTPD burrows.

Gray wolf LAA Direct effects to the gray wolf are expected to occur based on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 24.82 for exposure to non-target animals and RQ of 9.59 for exposure to

BTPDs both of which exceed the LOC of 0.1). Growth and reproductive effects cannot be precluded due to the absence of chronic data; however, growth and reproductive effects are not expected because mortality typically occurs as a result of acute exposure. Indirect effects from the loss of the prey base are expected because

effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial

invertebrates. No indirect effects from habitat loss are expected because this species does not use

BTPD burrows.

1 LAA=likely to adversely affect.



### 116

### Table 7.2. Effects Determination Summary for the Critical Habitat Impact Analysis
Species with Designated Critical

Habitat Effects

Determination Basis for Determination

Salt Creek tiger beetle HM 1 Reproductive effects are expected for the Sa lt Creek tiger beetle. Salt Creek tiger beetle larvae are potentially expose d to chlorophacinone residues through chlorophacinone exposed terrestrial inverteb rates. Dosed carcasses in a burying beetle study negatively affected number of emerged beetles (MRID 47383001). Similar affects are expected for the Salt Cr eek tiger beetle. No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. This species uses mud banks of streams and seeps in association with saline wetlands and exposed mud flats of saline wetlands which is distinct from the short grass prairie associated w ith BTPD habitat. No indirect effects from habitat loss are expected because th is species does not use BTPD burrows.

California condor No habitat

modification

expected Direct effects to the California condor are expected thro ugh their potential exposure to prey items that may have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals which exceeds the LOC of 0.1. No

indirect effects from the lo ss of prey base are expected because this species’ range does not overlap with BTPD range. No indirect effects from habitat loss are expected because this species does not use BTPD burrows. No habitat modification is expected because the critical habitat for the California condor does not overlap with the use area (BTPD hab itat). Critical habitat for the California condor has only been designated in California.

Whooping crane HM Direct effects to the whooping crane are expected to occur based on the potential for this species to consume the chloro phacinone bait (RQ of 0.89 which exceeds the LOC of 0.1) or other prey items that have consumed the chlorophacinone bait (RQ of 0.104 for exposure to non-target animals whic h exceeds the LOC of 0.1).

Indirect effects from the loss of the prey base are also expected because effects to individuals within populations have been demonstrated in mammals, birds, and

terrestrial invertebrates. No indirect effects from habita t loss are expected because this species does not use BTPD burrows. Habitat modification for the whooping crane is expected because the critical habitat for the whoo ping crane overlaps with the use area (BTPD habitat).

Canada lynx HM Direct effects to the Canada lynx are exp ected to occur based on the potential for this species to consume prey items that have consumed th e chlorophacinone bait (RQ of 23.30 for exposure to non-target animals and RQ of 9.00 for exposure to

BTPDs both of which exceed the LOC of 0. 1). No indirect effects from loss of prey base are expected because this species’ habitat is distinct from BTPD habitat. The Canada lynx is associated with the southern, transitional reaches of the cool and moist boreal forest. Where it occurs at these lower latitudes, the boreal forest

forms a mixed conifer and conifer-hardwood landscape. These habitat areas are distinct from the short grass prairie associ ated with BTPD habitat. No indirect effects from habitat loss are expected b ecause this species does not use BTPD burrows. Habitat modification for the Canada lynx is expected because the critical habitat for the Canada lynx overlaps with the use area (BTPD habitat).



### 117Preble’s meadow jumping mouse HM Direct effects to the Preble’s meadow ju mping mouse are expected to occur based on the potential for this species to consume the chlorophacinone bait (RQ of 41.35 which exceeds the LOC of 0.1). Indirect ef fects from the loss of the prey base are expected because effects to individuals within populations have been demonstrated in terrestrial invertebrates. Although this species makes nests both above and below ground, it does not appear to use other species’ rodent burrows. Habitat modification for the Preble’s meadow ju mping mouse is expected because the

critical habitat for the Preble’s meadow jumping mouse overlaps with the use area (BTPD habitat).

Mexican spotted owl HM Direct effects to the Mexican spotted ow l are expected to occur based on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 0.104 for ex posure to non-target animals which exceeds the LOC of 0.1). No indirect effe cts from loss of prey base are expected because this species’ habitat is distinct fr om BTPD habitat. Mexican spotted owls are found in old-growth or mature forests with unevenly aged stands of trees, high canopy, multi-storied levels, and high tree density as well as canyons with riparian

or conifer communities. In Arizona and New Mexico they are found in habitats associated with mixed conifer, pine-oak, Arizona cypress, oak woodlands, and associated riparian forests. These habita t areas are distinct from the short grass prairie associated with BTPD habitat. No indirect effects from habitat loss are expected because this species does not us e BTPD burrows. Habitat modification for the Mexican spotted owl is expected because the critical habitat for the Mexican spotted owl overlaps with the use area (BTPD habitat).

Piping plover HM Direct effects to the piping plover are expected to occur based on the potential for this species to consume prey items that have consumed th e chlorophacinone bait (RQ of 0.104 for exposure to non-target animals, which is used as a surrogate for invertebrate prey, which exceeds the LOC of 0.1). No indirect effects from the loss of the invertebrate prey base are ex pected because this species’ habitat is distinct from BTPD habitat. The plover’s home range within the BTPD range is usually limited to the wetland, lakeshore, or section of beach where its nest is

located. No indirect effects from habita t loss are expected because this species does not use BTPD burrows. Habitat modification for the piping plover is expected because the critical habitat for the piping plover overlaps with the use area (BTPD habitat).

New Mexican ridgenosed rattlesnake HM No direct effects based on survival to the New Mexican ridge-nosed rattlesnake are expected to occur (see Section 5.1.1.a. RQs of 0.018 for a 50 gram snake and RQ of 0.030 for a 500 gram snake. Neither of these RQs exceeds the LOC of 0.1). However, direct effects based on reproduction cannot be precluded because no reproduction data are available. Indirect effects from the loss of the prey base are expected because effects to individuals within populations have been demonstrated in mammals, birds, and terrestrial invertebra tes. No indirect effects from habitat loss are expected because th is species does not appear to use BTPD burrows.

Habitat modification for the New Mexican ridge-nosed rattlesnake is expected

because the critical habitat for the New Mexican ridge-nosed rattlesnake overlaps with the use area (BTPD habitat).

Gray wolf No habitat

modification

expected Direct effects to the gray wo lf are expected to occur base d on the potential for this species to consume prey items that have consumed the chlorophacinone bait (RQ of 24.82 for exposure to non-target animals and RQ of 9.59 for exposure to BTPDs both of which exceed the LOC of 0.1). In direct effects from the loss of the prey base are also expected because effects to individuals within populations have been demonstrated in mammals, birds, and terrestri al invertebrates. No indirect effects from habitat loss are expected because th is species does not use BTPD burrows. No habitat modification is expected because the critical habitat for the gray wolf does not overlap with the use area (BTPD ha bitat). Critical habitat for the gray wolf has only been designated in Minnesota and Michigan.

1 Habitat Modification



### 118The assessment endpoint for each species above is the modification of PCEs.



### Based on the conclusions of this assessment, a formal consultation with the U. S. Fish and Wildlife Service under Section 7 of the Endange red Species Act should be initiated.

When evaluating the significance of this risk assessment’s direct/indire ct and adverse habitat modification effects determinations, it is important to note that pesticide exposures and predicted risks to the listed species and its resources ( i.e ., food and habitat) are not expected to be uniform

across the action area since BTPDs are not uniform ly distributed across action area. Evaluation of the implication of this non-uniform distri bution of risk to the species would require information and assessment techniques that are not currently available. Examples of such information and methodology required for this ty pe of analysis would include the following:

• Enhanced information on the density and distribution of BTPD s within the action area and information on the density and dist ribution of the other 21 listed species

within the action area and information on th e density and distribution within their critical habitat of the nine species with critical habitat. This information would allow for quantitative extrapolation of the present risk assessment’s predictions of

individual effects to the proportion of the population extant within geographical areas where those effects are predic ted. Furthermore, such population information would allow for a more compre hensive evaluation of the significance of potential resource impairment to individuals of the listed species.

• Quantitative information on prey base require ments for the listed species. While existing information provides a preliminar y picture of the types of food sources utilized by the listed species, it does not establish minimal requirements to sustain healthy individuals at varyi ng life stages. Such information could be used to establish biologically rele vant thresholds of effects on the prey base, and ultimately establish geographical limits to those effects. This information could be used together with the density da ta discussed above to characterize the

likelihood of adverse effects to individuals.

• Information on population responses of prey base organisms to chlorophacinone. Currently, methodologies are limited to pr edicting exposures and likely levels of direct mortality, growth or reproduct ive impairment immediately following exposure to chlorophacinone. The degree to which repeated exposure events and the inherent demographic characteristic s of the prey population play into the extent to which prey resources may rec over is not predictable. An enhanced understanding of long-term prey respons es to chlorophacinone exposure would

allow for a more refined determination of the magnitude and duration of resource impairment, and together with the information described above, a more complete prediction of effects to i ndividual species a nd potential modification to critical

habitat.

119

### 8. References

Anonymous, 1981. Environmental and vertebrate chemistry – rodenticides. Agricultural Science Service, Research and Development Report, pp. 36-38.

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List of MRIDs:

47383002

43672005

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