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

Prospects for Mountain Lion Persistence in a Complex Urban
Landscape in Southern California
Seth P. D. Riley, Santa Monica Mountains National Recreation Area, 401 W. Hillcrest,
Dr., Thousand Oaks, CA 91360, USA, seth_riley@nps.gov
Jeff A. Sikich, Santa Monica Mountains National Recreation Area, 401 W. Hillcrest Dr.,
Thousand Oaks, CA 91360, USA, jeff_sikich@nps.gov
Eric C. York, Santa Monica Mountains National Recreation Area, 401 W. Hillcrest Dr.,
Thousand Oaks, CA 91360, USA (Deceased)
Raymond M. Sauvajot, Santa Monica Mountains National Recreation Area, 401 W.
Hillcrest Dr., Thousand Oaks, CA 91360, USA, ray_sauvajot@nps.gov
ABSTRACT Because of their extreme spatial requirements, large carnivores such as
mountain lions represent a significant challenge for conservation, especially in urban
areas where habitat loss and fragmentation are particularly severe. Since 2002, we have
been studying the behavior and ecology of mountain lions in the urban landscape of Santa
Monica Mountains National Recreation Area (SMMNRA) north of Los Angeles, CA.
From the beginning of the study, we assumed that none of the remaining blocks of habitat
were sufficient for a functioning population of mountain lions, and therefore that
successful movement across freeways and other barriers was critical for long-term
persistence. Although two individuals successfully crossed one freeway, none of the 9
radiocollared lions have crossed highway 101, the largest barrier that separates the Santa
Monica Mountains from likely source populations to the north. The first mountain lion in
the study has survived and even thrived for 5+ years, but 9 of the 11 lions documented in
the study so far have died: Two from anticoagulant rodenticide poisoning, two from
vehicle collisions, and five, including two females, from fights with adult males. We
were able to radio-track one litter of 4 kittens from 4 weeks old through their first two
years, and although all four survived the death of their mother at one year, only one
survived past 25 months. The two male kittens appeared to be attempting to disperse
from the territory of an adult male, but they were thwarted by roads and development.
Anthropogenic barriers to movement and dispersal may increase the frequency of
intraspecific strife. In this area, we also found widespread exposure of mountain lions to
anticoagulant rodenticides, as 7 of 8 animals tested were positive for 2-4 different
compounds. Despite these threats and the lack of known freeway crossings, mountain
lions persist across the landscape, and we continue to document new animals using
remote cameras. Through working to maintain and enhance connectivity, preserving
remaining habitat, and educating local communities about mountain lion behavior and
ecology, we hope to continue to fulfill the National Park Service mandate of preserving
all species in the parks, even mountain lions in an urban park like SMMNRA.
Proceedings of the Ninth Mountain Lion Workshop
117