In the San Francisco Bay Area (SFBA), the American badger (Taxidea taxus) has persisted within grasslands throughout the 20th century but continues to be exposed to increasing suburban sprawl. During the winter of 2002/2003, burrow transect surveys were used to assess the current distribution of badgers at 30 sites within the SFBA. Badger presence/absence, burrow density, and gopher and ground squirrel burrow densities were determined at each site. Using GIS, percent grassland, non-grassland, suburban land, agricultural land, and road/highway lengths were characterized within a three km radius of each site. Badgers were present at 15 sites, indicating that their distribution had contracted, particularly within habitat fragments east of San Francisco Bay and along urban edges. Suburban land use (p=0.01) and length of roads (p=0.06) were both less at sites where badgers were present. The best logistic regression model predicted that badgers were most likely present in grasslands where suburban land use and road lengths were low and gopher and ground squirrel burrow densities were high. Badgers appeared to be more sensitive than other carnivores to both habitat fragmentation and edge effects, perhaps due to their patchy distribution, sensitivity to human land use, and high road crossing mortality rates. The remaining populations in the SFBA may be especially susceptible to local extirpation events and should continue to be monitored in the future.
|School:||San Jose State University|
|School Location:||United States -- California|
|Source:||MAI 47/05M, Masters Abstracts International|
|Subjects:||Ecology, Organismal biology|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be