Tracking Lions in Your Backyard
The following article and accompanying photographs appeared in Santa Monica Mountains National Recreation Area's "Building Relations, Building Values: 2006 Year in Review." The Santa Monica Mountain Fund is proud to have made publication of that report possible through its financial support. Go to the "Donations" page, if you want to support the
wildlife conservation work described in the article; the scientists doing the work could sorely use your financial help.
In the coastal ranges above urban Los Angeles and the posh
neighborhoods of Malibu and Bel Air, mountain lions follow an
ancient cycle of navigating dense chaparral, traversing ridgelines
and canyons, hunting deer and raising young. Since 2002, the
National Park Service, with the support of California State Parks
and the Santa Monica Mountains Conservancy, has been tracking
mountain lion movements across the Santa Monica Mountains to
learn how this resilient species is behaving and surviving in the
country’s largest urban national park. Scientists also want to learn
how human development and urbanization might be impacting
the large cats.
Before this study, no one knew whether the lions sighted in the
Santa Monica Mountains actually lived here or were transient
animals from nearby Los Padres National Forest. NPS biologists
found the answer less than two years into their study, when they
documented the birth of four mountain lion cubs in a remote den
south of the Backbone Trail. This finding confirmed that the lions
are not only living in the mountains, but they are successfully
breeding here as well.
So far, the biologists have monitored eight mountain lions fitted
with GPS collars to gather critical information about the animals’
ecology and behavior. Identified threats to the lions include habitat
loss and fragmentation by roads and urban development, and
secondary poisoning from feeding on prey that have consumed
poisoned rodents. The monitored animals are elusive, staying out
of people’s way, and behaving “naturally” despite all the urban
development that surrounds them. Home range sizes for lions in
the Santa Monica Mountains – about 150 square miles for adult
males and 40 square miles for adult females – are not significantly
different from those in areas with little or no urban development.
As for feeding habits, mountain lions typically eat about one deer
per week, along with other smaller prey, and the lions in the Santa
Monica Mountains are no exception.
Biologists have also been monitoring the movements of mountain
lions to identify wildlife corridors – open spaces that link the Santa
Monica Mountains to other large natural areas and allow the lions
to move between them. Genetically, lions in the Santa Monica
Mountains are at the southern end of a larger population that extends
northward to Big Sur. The long-term survival of mountain
lion populations here will depend on their ability to move between
regions to maintain genetic diversity. Throughout California, one
of the greatest risks to wildlife is habitat loss and fragmentation
caused by rapid human population growth and development.
By conserving open space and wildlife corridors necessary for
long-range movements and preserving key crossing points at
roads and freeways, many wildlife species will benefit.
The NPS and its partners use information from studies like
these to develop management plans for protecting landscapes
and habitats critical to wildlife. These joint efforts promote the
long-term health of our native animal populations – including
mountain lions, the ecosystem’s top carnivore.
– Morgan Robertson, Wildlife Biologist
