Lions in the Santa Monica Mountains?

Mountain Lion
Female mountain lion P-35 in the Santa Susana Mountains.

National Park Service


Los Angeles is one of only two megacities in the world (the other is Mumbai) that have big cats living within the city limits. In a place more often associated with freeways and traffic, the fact that the city can support such large-ranging animals is a testament to the quality of open space and the habitat connectivity that still remains.

The National Park Service has been studying how mountain lions survive in an increasingly fragmented and urbanized landscape since 2002. Researchers have monitored more than 50 mountain lions in and around the Santa Monica Mountains. GPS collars provide detailed information about the animals' ecology and behavior.

Big Cats, Big Challenges

The good news for mountain lions in and around the Santa Monica Mountains is that the population is stable, with healthy rates of survival and reproduction.

The long-term survival of mountain lions in this region, however, is threatened by a number of factors, none more significant than the loss and fragmentation of habitat by roads and development. This leads not only to deaths from vehicle collisions, but also multiple cases of first-order inbreeding because animals are not able to disperse in and out of the area. Genetic analyses indicate that lions in the Santa Monica Mountains have among the lowest genetic diversity of any mountain lion population ever documented.

Another major threat to the species is the widespread presence of anticoagulant rodenticides, commonly known as rat poisons, in the environment. 13 of 14 mountain lions tested in the study have tested positive for one or more anticoagulant compounds and three have died of intoxicant poisoning. See infographic.

The number one cause of death for mountain lions in the study is intraspecific strife, or mountain lions killing other mountain lions. Though common in other populations, this rate may be exacerbated by the fact that mountain lions are basically trapped on an island of habitat, surrounded by freeways and the Pacific Ocean.

For more on causes of death during the study, read How Cougars Die in L.A. from Gridlocked, our wildlife blog.

Restoring Habitat Connectivity

The long-term survival of a mountain lion population here depends on their ability to move between regions to maintain genetic diversity and overall population health.

A solution to address this issue -- a wildlife crossing across the 101 Freeway, the biggest barrier between the Santa Monica Mountains and other large natural areas -- is currently being drafted by Caltrans. A private fundraising initiative, Save LA Cougars, is raising money for the effort.

If a wildlife crossing was built across the freeway, it would allow for mountain lions living north of the Santa Monica Mountains to travel into the range and for animals living south of the freeway to disperse out of the area.

A joint UCLA and National Park Service study recently found that the mountain lion population faces possible extinction.

Puma Profiles

From the very first study animal and former king of the mountains (P-1), to the only mountain lion documented to cross from north of the 101 Freeway to the south (P-12), to the famous mountain lion living in Griffith Park (P-22), each of these animals have helped us better understand the challenges and also the opportunities for keeping the population healthy and viable.

Read about each of the more than 50 study animals here.

Maps, Photos, & Videos

More than 100 high-resolution photos of mountain lions are available for download at our Flickr site. Several videos and maps are also available.

All maps and photos are part of the public domain (no need to request permission prior to using, though attribution to "National Park Service" is appreciated).

 
Infographic
This map reflects the GPS data points of lions P-1 through P-22, from the start of research in 2002 through December 2013. Each color represents a different mountain lion.
 

Safety

Mountain lions are solitary, elusive animals and sightings are extremely rare. Based on more than 75,000 GPS locations collected since 2002, it is clear that mountain lions prefer natural areas and attempt to avoid coming in contact with humans.

If you do encounter a mountain lion, make yourself appear as large and intimidating as possible by yelling, waving your arms, and even throwing objects in the direction of the animal. Slowly back away and allow space for the mountain lion to move away. Do not turn your back and run.

The California Department of Fish & Wildlife is responsible for managing mountain lions in the state of California and determining when a mountain lion is a threat to public safety.

Facts & Figures

• The National Park Service has studied more than 50 mountain lions in and around the Santa Monica Mountains.

• The #1 cause of death among study animals is intraspecific strife, or mountain lions killing other mountain lions. Read more here. 

• A total of 12 mountain lions have been struck and killed by vehicles in the study area since 2002 (note only three were study animals).
• A typical home range is around 200 square miles for adult males and 75 square miles for adult females.

• Mountain lions typically eat about one deer per week, along with other smaller prey as the opportunity arises. NPS researchers have analyzed more than 600 kills, of which 87% were mule deer (the second-most common prey was coyotes and then raccoons). 

• 13 of 14 mountain lions have tested positive for exposure to one or more anticoagulant rodenticides (rat poison) and three have died directly of poisoning.


Selected Publications

Benson, J. F., P. J. Mahoney, J. A. Sikich, L. E. K. Serieys, J. P. Pollinger, H. B. Ernest, and S. P. D. Riley. 2016. Interactions between demography, genetics, and landscape connectivity increase extinction probability for a small population of large carnivores in a major metropolitan area. Proceedings of the Royal Society B 283:20160957

Benson, J. F., J. A. Sikich, and S. P. D. Riley. 2016. Individual and population level resource selection patterns of mountain lions preying on mule deer along an urban-wildland gradient. PLoS ONE 11(7):e0158006. doi:10.1371/journal.pone.0158006.

Riley, S. P. D., L. E. K. Serieys, J. P. Pollinger, J. A. Sikich, L. Dalbeck, R. K. Wayne, and H. B. Ernest. 2014. Individual behavior dominates the dynamics of a mountain lion population in a highly fragmented urban landscape. Current Biology 24:1989-1994.

Bartos, M, S. Dao, D. Douk, S. Falzone, E. Gumerlock, S. Hoekstra, K. Kelly-Reif, D. Mori, C. Tang, C. Vasquez, J. Ward, S. Young, A. T. Morzillo, S. P. D. Riley, and T. Longcore. 2012. Use of Anticoagulant Rodenticides in Single-Family Neighborhoods Along an Urban-Wildland Interface in California. Cities and the Environment (CATE) 4: Article 12.

Gehrt, S. D., S. P. D. Riley, and B. L. Cypher. 2010. Urban Carnivores: Ecology, Conflict, and Conservation. Johns Hopkins University Press. 285 pp.

Riley, S. P. D., J. Pollinger, R. K. Wayne, R. M. Sauvajot, E. C. York, and T. K. Fuller. 2006. A southern California freeway in a physical and social barrier to gene flow in carnivores. Molecular Ecology 15:1733-1741.

Ng., S., R. M. Sauvajot, J. Dole, S. P. D. Riley, and T. Valone. 2004. Use of freeway undercrossings by wildlife in a fragmented urban landscape in southern California. Biological Conservation 115:499-507.

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