Boreal Toad (Bufo boreas boreas) A Technical Conservation Assessment Prepared for the USDA Forest Service, Rocky Mountain Region, Species Conservation Project May 25, 2005 Doug Keinath1 and Matt McGee1 with assistance from Lauren Livo2 1Wyoming Natural Diversity Database, P.O. Box 3381, Laramie, WY 82071 2EPO Biology, P.O. Box 0334, University of Colorado, Boulder, CO 80309 Peer Review Administered by Society for Conservation Biology Keinath, D. and M. McGee. (2005, May 25). Boreal Toad (Bufo boreas boreas): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/ assessments/borealtoad.pdf [date of access]. ACKNOWLEDGMENTS The authors would like to thank Deb Patla and Erin Muths for their suggestions during the preparation of this assessment. Also, many thanks go to Lauren Livo for advice and help with revising early drafts of this assessment. Thanks to Jason Bennet and Tessa Dutcher for assistance in preparing boreal toad location data for mapping. Thanks to Bill Turner for information and advice on amphibians in Wyoming. Finally, thanks to the Boreal Toad Recovery Team for continuing their efforts to conserve the boreal toad and documenting that effort to the best of their abilities … kudos! AUTHORS’ BIOGRAPHIES Doug Keinath is the Zoology Program Manager for the Wyoming Natural Diversity Database, which is a research unit of the University of Wyoming and a member of the Natural Heritage Network. He has been researching Wyoming’s wildlife for the past nine years and has 11 years experience in conducting technical and policy analyses for resource management professionals. His broader scope of research focuses on bat and small mammal ecology, survey, and monitoring at the population and landscape scales, and more recently on the spatially explicit predictive distribution modeling of sensitive elements (i.e., animals, plants, communities) of the Rocky Mountain West. Mr. Keinath earned a B.S. in Interdisciplinary Engineering (1993; magna cum laude) and a B.S. in Natural Resource Management (1993; with Distinction) from the University of Michigan and a M.S. in Wildlife Biology from the University of Wyoming. Matthew McGee was formerly a zoologist at the Wyoming Natural Diversity Database and is currently conducting field research in Alaska. He obtained a B.S. in Wildlife Biology from the University of Montana (1997) and a M.S. in Zoology and Physiology from the University of Wyoming (2002). COVER PHOTO CREDIT Boreal Toad (Bufo boreas boreas). Illustration by Summers Scholl. Used with permission. 2 3 SUMMARY OF KEY COMPONENTS FOR CONSERVATION OF THE BOREAL TOAD The boreal toad (Bufo boreas boreas) shows declines in population size and distribution across its range in western North America. The population in the Southern Rocky Mountains (Wyoming, Colorado, and New Mexico) is particularly vulnerable to extinction during declines as it is geographically isolated from all other populations of boreal toads. Scientists believe the chytrid fungus Batrachochytrium dendrobatidis to be a contributing factor in boreal toad declines since the 1970s and currently see it as the primary threat to boreal toad populations throughout the Southern Rocky Mountains. However, the impact of B. dendrobatidis is compounded by other threats, the most widespread being habitat alteration from human disturbances around wetlands and human-facilitated expansion of natural and introduced predators. Habitat fragmentation further isolates breeding populations, which increases the effects of these widespread threats and the risk associated with other threats, such as local changes in water quality, timber harvest, livestock grazing, fire, and toxic chemicals (e.g., pesticides and herbicides). The main conservation concerns for land managers should be managing disease, cataloging and monitoring population status, delineating important habitat, and protecting delineated habitat. Of specific importance are developing techniques to effectively detect and treat Batrachochytrium dendrobatidis infections in both wild and captive populations of boreal toads and identifying and protecting current breeding sites from habitat degradation, especially in the Southern Rocky Mountains. In order to ensure the survival of boreal toads in Region 2, local management plans must assess the impact of the threats discussed in this document at both the scale of the landscape connecting boreal toad populations and within individual populations. Further, it is necessary for land managers to preserve critical wetland and terrestrial habitats not only by directly protecting these areas but also by identifying important processes that create and maintain these habitats and working to ensure that these processes are functioning properly. 2 3 TABLE OF CONTENTS ACKNOWLEDGMENTS ..............................................................................................................................................2 AUTHORS’ BIOGRAPHIES .........................................................................................................................................2 COVER PHOTO CREDIT .............................................................................................................................................2 SUMMARY OF KEY COMPONENTS FOR CONSERVATION OF THE BOREAL TOAD......................................3 LIST OF TABLES AND FIGURES ...............................................................................................................................6 INTRODUCTION ..........................................................................................................................................................7 Goal............................................................................................................................................................................7 Scope..........................................................................................................................................................................7 Uncertainty and Limitations.......................................................................................................................................8 Peer Review and Treatment of Web Publications ......................................................................................................8 MANAGEMENT STATUS AND NATURAL HISTORY .............................................................................................8 Management Status ....................................................................................................................................................8 Federal Endangered Species Act ...........................................................................................................................8 Bureau of Land Management................................................................................................................................8 USDA Forest Service ............................................................................................................................................9 State wildlife agencies...........................................................................................................................................9 Natural Heritage Program .....................................................................................................................................9 Existing Regulatory Mechanisms, Management Plans, and Conservation Strategies...............................................9 Existing regulatory mechanisms ...........................................................................................................................9 Existing management plans.................................................................................................................................10 Southern Rocky Mountain Population ...........................................................................................................10 Northern Rocky Mountain Population ...........................................................................................................10 Existing conservation strategies..........................................................................................................................10 Biology and Ecology................................................................................................................................................11 Description ..........................................................................................................................................................11 Systematics..........................................................................................................................................................11 Range, distribution, and distribution trends ........................................................................................................14 Abundance and population trends .......................................................................................................................22 Activity and movement .......................................................................................................................................26 Habitat .................................................................................................................................................................27 General requirements......................................................................................................................................27