P-23, a female mountain lion studied at Santa Monica Mountains NRA since she was only a few weeks old, has been killed/NPS

A female mountain lion that has been studied since she was just a few weeks old has been killed in an apparent collision with a vehicle, according to staff at Santa Monica Mountains National Recreation Area in California.

The remains of P-23 were discovered earlier this week near the Malibu Canyon Road in the NRA.

“We’ve been tracking P-23 since she was just a few weeks old and have documented her dispersal from her mom, establishment of a home range as an adult, and birth to three litters of kittens,” said Jeff Sikich, a National Park Service wildlife biologist. “Unfortunately, her life came to an end prematurely due to the challenge of navigating the complex road network in this area.”

P-23 was five-and-a-half years old, and her most recent offspring are now approximately one year old. Biologists tagged one of the kittens, P-54, at a few weeks of age, but only learned of the additional kitten after trail cameras picked him or her travelling with mom and sister. 

Given that the two juvenile cats have already reached the one-year mark, biologists believe they will be able to fend for themselves. Mountain lions typically leave their mom between one and one-a-half years old. P-23 dispersed from her mother at one year of age. 

P-23, like several other mountain lions in the Santa Monica Mountains, is a product of first order inbreeding. Her mother, P-19, mated with P-12, who is both her father and grandfather. Moreover, P-23 also later mated with P-12, her father, in another example of this close inbreeding.

P-23's home range surrounded a portion of the Malibu Canyon Road where she was killed/NPS map, arrow points to P-23's home range

In 2013, P-23 attracted major news coverage when she was photographed on top of a deer on Mulholland Highway. Photos of the encounter went viral on the park’s Facebook page. 

P-23 is the 18th known case of a mountain lion killed on a freeway or road in the study region since 2002. Southern California’s extensive road network is both a source of mortality, as in this case, and a major barrier to movement in the case of large and busy freeways, which have particularly hemmed in the mountain lion population in the Santa Monica Mountains. 

The National Park Service has been studying mountain lions in and around the Santa Monica Mountains since 2002 to determine how they survive in an increasingly fragmented and urbanized environment.

The California Department of Fish and Wildlife, which is responsible for overseeing the management and conservation of mountain lions in the state, will conduct a necropsy.