Mountain lions are not threatened nor endangered in California. In fact, the lion population is relatively high in California and their numbers appear to be stable. Mountain lions are legally classified as "specially protected species". This has nothing to do with their relative abundance and does not imply that they are rare.
Any statewide estimate of the mountain lion population is just a "guesstimate." Mountain lion studies over the last 30 years have estimated population densities for different habitat types around the state. These density estimates varied from zero to 10 lions per 100 square miles, and were simply expanded to the total amount of each habitat type available. In 1996 CDFW used this method, relying on density estimates from previous studies, to derive as estimate of between 4,000 and 6,000 mountain lions statewide. In 2014, CDFW began working to update this estimate with more rigorous field and data analysis methods. CDFW anticipates completing this current effort within a few years.
More than half of California is prime mountain lion habitat. Generally speaking, mountain lions can be found wherever deer are present, since deer are a mountain lion's main food source. Foothills and mountains and most suitable mountain lion habitat, while valleys and deserts are considered unsuitable.
There are indications that mountain lion activity, such as depredation, attacks on people, and predation on prey populations, peaked in 1996, then decreased somewhat, and have remained stable for the past several years. In 2014 CDFW began carrying out a statewide mountain lion study to determine status and trend of mountain lion numbers across California. CDFW anticipates developing a baseline population estimate within a few years, from which on-going monitoring can estimate localized trends if continued.
With the passage of Proposition 117 in 1990, mountain lions became a "specially protected species," making mountain lion hunting illegal in California. This status and other statutes prohibit the California Department of Fish and Wildlife from recommending a hunting season for lions, and it is illegal to take, injure, possess, transport, import, or sell any mountain lion or part of a mountain lion. Mountain lions may be killed only 1) if a depredation permit is issued to take a specific lion killing livestock or pets; 2) to preserve public safety; or 3) to protect listed bighorn sheep.
Under the CDFW's Public Safety Wildlife Guidelines, an animal is deemed to be a public safety threat if there is “a likelihood of human injury based on the totality of the circumstances.” Factors that are considered include the lion's behavior and its proximity to schools, playgrounds and other public gathering places. The determination of whether an animal is a public safety threat is made by the CDFW or local law enforcement personnel on the scene.
When a mountain lion is declared a public safety threat, the CDFW's goal is to eliminate the threat in the most humane manner possible. Capturing a wild animal that is accustomed to traveling great distances and confining it to a relatively small enclosure is not a humane option.
When an animal is displaying unusually bold or aggressive behavior toward humans, the CDFW will not relocate the animal because of the risk it could pose to others.
Sometimes disease will cause an animal to behave strangely. Some mountain lions killed for public safety reasons have tested positive for feline leukemia. A mountain lion that attacked a man in Mendocino County in 1994 tested positive for rabies. Usually, there is no apparent explanation for why a mountain lion seems to abandon its instinctive wariness of humans. Mountain lions are typically solitary and elusive. Studies of collared mountain lions show that they often co-exist around people, unseen and unheard.
Statistically speaking, a person is one thousand times more likely to be struck by lightning than attacked by a mountain lion. That said, mountain lions are wild animals and, like any wildlife, can be dangerous. People who live in mountain lion habitat can take precautions to reduce their risk of encountering a mountain lion. By deer-proofing the landscape, homeowners can avoid attracting a lion's main food source. Removing dense vegetation from around the home and installing outdoor lighting will make it difficult for mountain lions to approach unseen.
Mountain lion attacks on humans are rare. There have been only 16 verified mountain lion attacks on humans in California since 1890, six of them fatal. The last documented attack occurred in September, 2014, in Santa Clara County.