Preferred Session: Ecology and Conservation of Mammals Type of paper: oral presentation Paper Title: Summary of USGS research on the American badger (Taxidea taxus) in San Diego County Devin Adsit-Morris, Western Ecological Research Center, U.S. Geological Survey,4165 Spruance Road, San Diego, CA 92101, dadsit-morris@usgs.gov, (619)840-0127; Co-authors Cheryl Brehme; Philip Gould; and Robert Fisher Abstract: The American Badger is a wide-ranging mid-sized predator associated with grassland and upland habitats and is a target species for monitoring regional-scale connectivity under the San Diego Multiple Species Conservation Plan. Due to habitat loss, fragmentation, and road mortality, badgers were considered at risk of loss from the region. Previous to 2011, there was little information of their presence within San Diego County. Since then, we have employed multiple methods for detecting badgers including canine scent surveys, sign surveys (burrows, digs, tracks), infrared cameras, public outreach, roadkill reports, and individual identification using facial markings. Canine surveys found 203 scat samples with 25 confirmed to be badger. Over 300 sign surveys produced 80 confirmed badger occurrences, outreach produced over 200 reports with 110 confirmed to be badger, and 32 road mortalities were documented. We theorize that badgers in the County are at low densities and operating on a large spatial scale. Distribution models and least-cost paths were developed using badger data, slope, soils, and vegetation. Models and roadkill data have enabled us to model high-quality habitats and identify roads of concern. Future plans include refining habitat suitability models, conducting radiotelemetry, and identifying of locations for road passages to facilitate safe road crossings.