Black-Tailed Prairie Dog Study of Eastern Colorado Colorado Department of Natural Resources October 27, 2000 Black-Tailed Prairie Dog Study of Eastern Colorado Prepared for: Colorado Department of Natural Resources Executive Director’s Office 1313 Sherman Street, Room 718 Denver, CO 80203 Contact: Tim Pollard Assistant Director (303) 866-3311 Prepared by: EDAW, Inc. 240 East Mountain Avenue Fort Collins, CO 80524 Contact: Brian Hoffmann Manager of Biological Services (970) 484-6073 October 27, 2000 TABLE OF CONTENTS PAGE Introduction, Background, and Objectives............................................. 1 Regulatory Background............................................................................... 1 Study Initiation............................................................................................. 1 History of Black-tailed Prairie Dogs in Colorado.......................................... 1 Consultations with Species Experts and Literature Review......................... 3 Project Objectives ....................................................................................... 4 Project Challenges ...................................................................................... 4 Review of Species Threats in Colorado .................................................. 6 Habitat Fragmentation................................................................................. 6 Sylvatic Plague............................................................................................ 7 Recreational Shooting................................................................................. 8 Control Programs........................................................................................ 9 Range and Potential Habitat in Colorado................................................ 11 Data Collection Methodology................................................................... 14 Existing Data Compilation ........................................................................... 14 Field Verification.......................................................................................... 15 Field Survey ................................................................................................ 16 GIS Database.............................................................................................. 17 Final Report Page i Black-Tailed Prairie Dog Study of Eastern Colorado Results ....................................................................................................... 18 Database Summary .................................................................................... 18 2000 Field Survey Accomplishments .......................................................... 19 Post-Survey Summary of Database ............................................................ 19 Variability in Colony Status ......................................................................... 20 Total Active and Inactive Prairie Dog Acreage............................................ 20 Active Prairie Dog Town Size...................................................................... 21 County-by-County Results .......................................................................... 21 Other Sensitive Species Sightings .............................................................. 23 Considerations for Colorado’s Black-Tailed Prairie Dog Conservation Strategy.................................... 25 References Cited....................................................................................... 30 Appendix A – Metadata Appendix B – County Maps of Known Prairie Dog Towns List of Tables Table 1 A Summary of Data Sources....................................................... 14 Table 2 Database Source Summary ........................................................ 18 Table 3 Survey Accomplishments in 2000 ............................................... 19 Table 4 Colony Status Following 2000 Field Surveys .............................. 20 Table 5 Changes in Colony Status Since Last Survey............................. 20 Table 6 Statewide Results – Active and Inactive Acreage ....................... 21 Table 7 Black-tailed Prairie Dog Town Size ............................................. 21 Table 8 County-by-County Summary of Black-tailed Prairie Dog Acreage 22 List of Figures Figure 1 Range of Black-tailed Prairie Dog in Eastern Colorado............... 11 Figure 2 Map of Potential Black-tailed Prairie Dog Habitat in Colorado .... 13 Final Report Page ii Black-Tailed Prairie Dog Study of Eastern Colorado CONTRIBUTORS The EDAW Team A number of EDAW employees were involved with this project and deserve mentioning here. The two primary contributors were Brian Hoffmann, Project Manager and Senior Wildlife Biologist, and Bruce Meighen, a Resource Management and Senior GIS Specialist. Brian directed all work related to species biology issues, and Bruce led all GIS mapping and data base tasks. Additionally, Tom Keith performed senior quality assurance and Principal-in- Charge roles, and Craig Severn served as a field surveyor. There were two subconsultants that played key, crucial roles on the EDAW team for this project. Bill Lehman, a former long-term USFWS biologist who is now an independent subconsultant in Boise, provided a critical review of the document. Dr. Jim Fitzgerald, a nationally renowned prairie dog expert, provided advice and strategic direction throughout the project and helped write the conservation strategy recommendations section. Finally, this effort would not have been possible without the diligent efforts of the field survey team. Special thanks go to three subconsultants whose knowledge of the short-grass prairie ecosystem proved invaluable: John Norman (surveyed the eastern counties), Darby Finley (the southern counties), and Ted Toombs (the southeastern counties). Also, thanks to Craig Severn (the northeastern counties) and Brian Hoffmann (parts of the Front Range) for rounding out the field survey billet. Acknowledgements Many agencies and organizations need to be thanked for contributing data to this study’s baseline, except that there are too many to mention here. Two that must be recognized, though, because of their outstanding contributions are the Colorado Bird Observatory (CBO) staff, most notably Scott Hutchings, and the Colorado Division of Wildlife, particularly Jennie Slater. CBO went “above and beyond the call of duty” in their contributions, providing data that greatly expanded the project’s state of knowledge concerning prairie dog town locations throughout the eastern plains of Colorado. Jennie Slater, the state’s Grassland Species Coordinator, who is also chairing the state’s Black-tailed Prairie Dog Working Group, helped guide this project to its successful conclusion. Thanks to all! Final Report Page iii Black-Tailed Prairie Dog Study of Eastern Colorado INTRODUCTION, BACKGROUND and OBJECTIVES Regulatory Background On July 30, 1998, the National Wildlife Federation (NWF) filed a petition with the U.S. Fish and Wildlife Service (USFWS) to list the black-tailed prairie dog (Cynomys ludovicianus) as “threatened” under the federal Endangered Species Act (ESA). On February 4, 2000, USFWS published a notice in the Federal Register summarizing its 12-month Administrative Findings on the petition, within which it was cited that the species “warrants listing”, but that higher priority species deserving of more immediate attention “precludes the listing of the black- tailed prairie dog at this time” (a.k.a., a “warranted but precluded” finding). So, for now, the species is officially considered a federal candidate for listing, and USFWS will review its status every 12 months. What this federal action has stimulated, though, is a response by the various states that make up the historic range of the black-tailed prairie dog to voluntarily develop conservation strategies for the species. The USFWS expects that state-implemented conservation programs will both forestall eventual listing and promote recovery of the black- tailed prairie dog. Study Initiation EDAW was contracted by the Colorado Department of Natural Resources (DNR) in March 2000 to complete a Black-Tailed Prairie Dog Study of Eastern Colorado, hereafter referred to as “the project”. The focus of the project was to establish a baseline of what is known about this species in Colorado. This included contacting species experts, and locating sources of data pertaining to black-tailed prairie dog town locations in Colorado. The objective was to assemble the various data sets into a single GIS database to serve as the state’s baseline for the species. The database would then be updated as part of this study using field surveys to verify the locations and status of prairie dog towns not visited in recent years. During the updating process, new prairie dog towns observed along the survey routes would also be mapped and included in the baseline. The overall goal of this project was to develop a baseline of known black-tailed prairie dog occurrences in Colorado that would be useful in setting the state’s conservation strategy for the species. History of Black-tailed Prairie Dogs in Colorado Because the overall purpose of this study is to establish the range and amount of occupied black-tailed prairie dog habitat in Colorado, it would perhaps be useful to first summarize what is known about their historic range in the state. Also, the reader should be aware that the terms prairie dog “town” and “colony” are essentially interchangeable,