Proceedings of the Ninth Mountain Lion Workshop - Carnivore ...

Puma Movements Relative to Housing Density in Southern California
Christopher L. Burdett, Colorado State University, Department of Fish, Wildlife, and
Conservation Biology, Fort Collins, CO 80523, USA cburdett@warnercnr.colostate.edu
Kevin Crooks, Colorado State University, Department of Fish, Wildlife, and Conservation
Biology, Fort Collins, CO 80523, USA kcrooks@warnercnr.colostate.edu
David M. Theobald, Colorado State University, Department of Human Dimensions of Natural
Resources and Natural Resources Ecology Lab, Fort Collins, CO 80523, USA,
davet@warnercnr.colostate.edu
Ken Wilson, Colorado State University, Department of Fish, Wildlife, and Conservation Biology,
Fort Collins, CO 80523, USA, kenneth.wilson@colostate.edu
Walter Boyce, University of California, Department of Pathology, Microbiology, and
Immunology, Wildlife Health Center, Davis, CA 95616, USA, wmboyce@ucdavis.edu
Erin Boydston, USGS Western Ecological Research Center, 320 Commerce, Suite 150, Irvine CA
92602, USA, eboydston@usgs.gov
Lisa Lyren, USGS Western Ecological Research Center, 320 Commerce, Suite 150, Irvine CA
92602, USA, llyren@usgs.gov
ABSTRACT The puma (Puma concolor) is widely distributed throughout the western
U.S. However, expanding human development is increasingly encroaching on puma
habitat throughout the western U.S., which may isolate breeding populations and increase
the potential for human-puma conflicts. We studied the movements of pumas relative to
a gradient of human housing densities (public, undeveloped private, rural, exurban,
suburban, and urban land uses) in southern California. Our goal was to better understand
how the regional puma population will be affected by increased development projected to
occur in future decades. We collected over 43,000 locations from 31 pumas wearing
global positioning system (GPS) telemetry collars in Orange, Riverside, San Diego, and
Imperial Counties in southern California. Current estimates of housing density were
developed from U.S. Census Bureau data. Projections of future housing densities were
developed with a supply-demand-allocation approach using patterns estimated from
historical development patterns and parameters reflecting accessibility to human
infrastructure like roads. Most puma locations were associated with public land (65%),
undeveloped private land (14%), and rural land (14%). At the study-area scale, pumas
selected for public land, used undeveloped private and rural areas in proportion to their
availability, and selected against areas with housing densities that had less than 40 acres
per unit. Approximately 9% of our puma locations occurred in areas that were projected
to become suburban or urban areas in 2030. Not surprisingly, the future of pumas in the
southern California landscape is dependent on public land. Therefore, maintaining
functional connectivity between patches of public land should be a high conservation
priority in this highly urbanized landscape. For example, a critical linkage between
pumas inhabiting the Santa Ana Mountains and the Laguna Mountains appears highly
threatened by development projections by 2030. Future analyses include: (1) examining
the response to human development and other habitat features at finer spatial scales, and
(2) using these empirical results to build a habitat model to predict how human
development will affect puma distribution at a broader spatial scale that encompasses the
western U.S.
Proceedings of the Ninth Mountain Lion Workshop
116