Mountain lion mortality charts show how bumpy the road is for cougars

As Los Angeles prepares to celebrate the life of beloved mountain lion P-22 this weekend, mountain lion mortality maps from the University of California, Davis show many cougars along California’s roads and highways are suffering a similar fate.

The maps and accompanying report, produced by the UC Davis Road Ecology Center, show that between 2015 and 2022, one or two mountain lions were killed on California’s roads and highways every week.

This number has gradually declined over the past seven years, although it is unclear whether this is due to the decline in the mountain lion population itself or other factors. A nationwide estimate of the mountain lion population is currently pending, and scientists are working on survival estimates to shed light on these questions.

“We know that the additional mortality from cars over time, particularly for small, isolated populations, greatly increases the threats they already face,” said Fraser Shilling, director of the UC Davis Road Ecology Center. “P-22’s persistence in life and the ultimate tragedy of his death in a vehicle collision underscores the plight of mountain lions across California who face constant threats from traffic while going about their natural lives.”

Dangerous places for lions

The maps show that Southern California and the Bay Area harbor the most dangerous roads for mountain lions, with local extinctions becoming more likely each year. Particularly problematic motorways are:

• I-280, south of San Francisco
• I-15, south of Temecula
• I-5 in Siskiyou County
• SR 74 (Ortega Highway) in the Santa Ana Mountains

Mountain lion expert Winston Vickers, a wildlife veterinarian at UC Davis School of Veterinary Medicine, contributed data used in creating the maps.

“Regionally, parts of Southern California are particularly dangerous for mountain lions, with traffic being the leading cause of death,” Vickers said. “In other areas, direct conflict with livestock results in mountain lions being killed. Both together is clearly bad, especially for small, isolated populations. Busy highways also cut off mountain lions from potential mates, greatly reducing their genetic diversity and threatening their existence.”

P-22: Hollywood legend

P-22 was a fierce mountain lion who became a Hollywood legend. He lived in Griffith Park for most of his 12 years, where his picture became famous walking under the Hollywood sign.

Dodging traffic throughout his life, he became the first known mountain lion to successfully cross the 405 and 101 freeways before settling in Griffith Park. There he was cut off from other mountain lions who could continue his legacy.

Instead, his life became a symbol of the need for animal crossings and a reminder of the wild even in the most urban of settings. His captivating face and story helped raise funds for the world’s largest wildlife overcrossing — the Wallis-Annenberg Wildlife Overcrossing — which broke ground last April to create a corridor between the Santa Monica mountains and areas to the north create.

P-22 was hit by a vehicle in December 2022. Already weakened by old age and other illnesses before the collision, he was euthanized on December 17 due to health problems including kidney and heart disease, chronic weight loss and a parasitic skin infection.

The P-22 Celebration of Life public will be held on Saturday, February 4th in Los Angeles at the Greek Theater in Griffith Park.

Another mountain lion

On Sunday, January 22, another wild mountain lion, P-81, was found dead from a possible vehicle impact on the Pacific Coast Highway in the western Santa Monica Mountains.

“Mountain lions in Southern California symbolize the ability of America’s lions to thrive in even our largest megacities,” said Mari Galloway, California programming director of Wildlands Network. “But to spot another mountain lion killed by a vehicle as we prepare for the P-22 memorial, we must address whether we are doing enough for our wild neighbors.”