Draft Environmental Assessment for Reestablishment of Sonoran Pronghorn U.S. Department of the Interior Fish and Wildlife Service Region 2 1 October 2009 This page left blank intentionally 1 October 2009 TABLE OF CONTENTS 1.0 PURPOSE OF AND NEED FOR ACTION............................................ 1 1.1 Proposed Action.............................................................. 2 1.2 Project Need................................................................. 6 1.3 Background Information on Sonoran Pronghorn . 9 1.3.1 Taxonomy.............................................................. 9 1.3.2 Historic Distribution and Abundance......................................... 9 1.3.3 Current Distribution and Abundance........................................ 10 1.3.4 Life History............................................................ 12 1.3.5 Habitat................................................................ 13 1.3.6 Food and Water......................................................... 18 1.3.7 Home Range, Movement, and Habitat Area Requirements . 18 1.4 Project Purpose ............................................................. 19 1.5 Decision to be Made.......................................................... 19 1.6 Compliance with Laws, Regulations, and Plans . 19 1.7 Permitting Requirements and Authorizations Needed . 21 1.8 Scoping Summary............................................................ 21 1.8.1 Internal Agency Scoping.................................................. 21 1.8.2 Public Scoping ......................................................... 21 1.8.3 Issue Identification...................................................... 22 2.0 ALTERNATIVES, INCLUDING NO ACTION ....................................... 24 2.1 Alternative Formulation....................................................... 24 2.1.1 Reestablishment Technique Options ........................................ 24 2.1.2 Legal Status Options..................................................... 25 2.1.3 Location Options........................................................ 26 2.1.4 Additional Alternative Development Considerations . 29 2.2 Alternatives Analyzed in Detail................................................. 30 2.2.1 Alternative I: No Action.................................................. 31 2.2.2 Alternative II: Captive-Breeding Pen at Kofa NWR, Holding Pen at BMGR-East . 31 2.2.3 Alternative III: Captive-Breeding Pen at BMGR-East . 37 2.2.4 Nonessential Experimental Designation and 4(d) Rule . 39 2.3 Mitigation Measures.......................................................... 42 2.4 Monitoring and Adaptive Management Plan....................................... 43 2.5 Comparison of Alternatives.................................................... 43 3.0 EXISTING CONDITIONS AND EFFECTS.......................................... 49 3.1 Assessment of Impacts........................................................ 49 3.1.1 Impact Assessment Method ............................................... 49 3.1.2 Ramifications of Nonessential Experimental Population Designation . 51 Environmental Assessment for Reestablishment of Sonoran Pronghorn Page i 1 October 2009 3.2 Conservation Status of Sonoran Pronghorn........................................ 51 3.2.1 Existing Conditions...................................................... 51 3.2.2 Effects on Conservation Status of Sonoran Pronghorn . 57 3.3 Wildlife, Including Special-Status Animal Species . 64 3.3.1 Existing Conditions...................................................... 64 3.3.2 Effects on Wildlife, Including Special-Status Animal Species . 71 3.4 Vegetation, Including Special-Status Plant Species . 75 3.4.1 Existing Conditions...................................................... 75 3.4.2 Effects on Vegetation, Including Special-Status Plant Species . 82 3.5 Water ..................................................................... 84 3.5.1 Existing Conditions...................................................... 84 3.5.2 Effects on Water........................................................ 85 3.6 Air Quality................................................................. 86 3.6.1 Existing Conditions...................................................... 86 3.6.2 Effects on Air Quality.................................................... 88 3.7 Noise Levels................................................................ 90 3.7.1 Existing Conditions...................................................... 90 3.7.2 Effects on Noise Levels .................................................. 91 3.8 Socioeconomic Conditions and Environmental Justice . 92 3.8.1 Existing Conditions...................................................... 92 3.8.2 Effects on Socioeconomic Conditions and Environmental Justice . 96 3.9 Cultural Resources........................................................... 98 3.9.1 Existing Conditions...................................................... 98 3.9.2 Effects on Cultural Resources ............................................. 99 3.10 Recreation, Wilderness, and Public Access . 99 3.10.1 Existing Conditions..................................................... 99 3.10.2 Effects on Recreation, Wilderness, and Public Access . 105 3.11 Military Operations ........................................................ 106 3.11.1 Existing Conditions.................................................... 106 3.11.2 Effects on Military Operations........................................... 107 3.12 Livestock Grazing ......................................................... 108 3.12.1 Existing Conditions.................................................... 108 3.12.2 Effects on Livestock Grazing............................................ 111 3.13 Hazardous Materials........................................................ 112 3.13.1 Existing Conditions.................................................... 112 3.13.2 Effects on Hazardous Materials .......................................... 112 3.14 Cumulative Effects......................................................... 112 3.15 Irreversible and Irretrievable Commitment of Resources . 119 4.0 COUNCIL ON ENVIRONMENTAL QUALITY ANALYSIS OF SIGNIFICANCE . 120 5.0 EA PREPARERS .............................................................. 121 6.0 CONSULTATION AND COORDINATION......................................... 122 Environmental Assessment for Reestablishment of Sonoran Pronghorn Page ii 1 October 2009 7.0 LITERATURE CITED.......................................................... 123 LIST OF TABLES Table 1. Estimated U.S. population size of Sonoran pronghorn from 1924 to July 2009. 11 Table 2. Screening criteria scores for potential Sonoran pronghorn reestablishment areas. 28 Table 3. Land status of proposed Sonoran pronghorn reestablishment areas A and D. 31 Table 4. Summary of potential effects on resource categories from each alternative. 44 Table 5. Land status within the current U.S. range of Sonoran pronghorn. 52 Table 6. Sonoran pronghorn recruitment and release from the captive-rearing pen, 2004-2009. 56 Table 7. Extrapolation procedure for application of modeled habitat to all of Area D. 58 Table 8. Potential habitat, in square miles, for Sonoran pronghorn under the three alternatives . 59 Table 9. Special-status animal species in the four counties encompassing the action area. 65 Table 10. Summary of effects on special-status animal species from alternatives II and III. 72 Table 11. Special-status plant species in the four counties encompassing the action area. 78 Table 12. Summary of effects on special-status plant species from alternatives II and III. 83 Table 13. Air quality attainment status.................................................. 86 Table 14. Counties in alternative Sonoran pronghorn reintroduction areas A and D . 93 Table 15. Population of the counties comprising areas A and D . 94 Table 16. Economic characteristics of alternative Sonoran pronghorn reintroduction areas . 96 Table 17. Estimated costs of alternatives II and III over the 10-year analysis period . 97 Table 18. Federal Wilderness areas potential Sonoran pronghorn reintroduction areas A and D. 100 Table 19. Estimated visitor use days to King Valley, Kofa NWR, 1998-2008. 103 Table 20. List of reasonably foreseeable future actions planned in the action area. 113 Table 21. Summary of cumulative effects of the action alternatives . 114 Environmental Assessment for Reestablishment of Sonoran Pronghorn Page iii 1 October 2009 LIST OF FIGURES Figure 1. Historic and current ranges of Sonoran pronghorn. 3 Figure 2. Location of the proposed captive-breeding pen at Kofa NWR . 4 Figure 3. Location of the proposed holding pen on the Barry M. Goldwater Range . 5 Figure 4. Sonoran pronghorn doe (with radiocollar) and her fawn . 7 Figure 5. Sonoran pronghorn captive-breeding pen at Cabeza Prieta NWR. 8 Figure 6. Sonoran pronghorn in Arizona Upland vegetation . 14 Figure 7. Chain-fruit cholla at Cabeza Prieta NWR . 15 Figure 8. Lower Colorado River Valley vegetation at Kofa NWR . 17 Figure 9. Potential reestablishment areas for Sonoran pronghorn . 27 Figure 10. Detailed location of proposed captive-breeding pen site in Area A on Kofa NWR . 32 Figure 11. Detailed location of proposed holding pen site in Area D on BMGR-East. 34 Figure 12. Detailed location of alternative captive-breeding pen site in Area D on BMR-East . 38 Figure 13. Proposed nonessential experimental population area for Sonoran pronghorn. 40 Figure 14. Cause and effect diagram