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 nearly 100 mountain lions in and around the Santa Monica Mountains north of Los Angeles. GPS radio-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, along with a similarly isolated population in the Santa Ana Mountains south of LA, have the lowest levels of genetic diversity ever documented in the West. The only population with lower levels was in south Florida in the mid 90’s when Florida panthers were on their way to extinction.
Another major threat to the species is the widespread presence of anticoagulant rodenticides, commonly known as rat poisons, in the environment. Twenty-seven out of 28 mountain lions tested in the study have tested positive for one or more anticoagulant compounds and six have died from anticoagulant rodenticide poisoning (as of January 2021).
A leading 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.
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.
From the very first study animal and former king of the mountains (P-1), to the first 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.
More than 200 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).
Mountain lions are solitary, elusive animals and sightings are extremely rare. Based on more than 150,000 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 National Park Service has studied 95 mountain lions in and around the Santa Monica Mountains.
• The major causes of death among study animals is intraspecific strife (mountain lions killing other mountain lions), vehicle collisions, and rodenticide poisoning.
• A total of 23 mountain lions have been struck and killed by vehicles in the study area since 2002.
• A typical home range is around 150 square miles for adult males and 65 square miles for adult females in our region.
• Mountain lions typically eat about one deer per week, along with other smaller prey as the opportunity arises. NPS researchers have analyzed more than 700 kills, of which 87% were mule deer (the second-most common prey was coyotes and then raccoons).
• 27 of 28 mountain lions have tested positive for exposure to one or more anticoagulant rodenticides (rat poison) and six have died directly of poisoning. *as of January 27, 2021
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