New Mortality Map Shows Danger Zones For California Cougars; Despite Protections And Public Support Lions Face Great Danger

We have reported extensively on the risks California mountain lions (Puma concolor) face in California. That danger was recently highlighted by the death of P-22. He was suffering from old age but was also very likely hit by a car in his last days. The most famous mountain lion was a long-time subject of study by conservation agencies. Researchers have now created a “mortality map” to highlight the danger.

California is a paradox for mountain lions (cougars). Almost the entire state is prime cougar country. There are areas where they do quite well. The state has an estimated population of up to 6,000. However, there are areas where they face local extinction. Often due to road hazards. The road hazards also segment cougar territory. This leads to inbreeding and can result in local extinction too.

P-22 lived a long and famous life. Old age and probable car injuries led to his recapture and euthanasia. During his life he successfully crossed freeways twice – a very rare feat.

Now a new mortality map provides insight into the most dangerous areas for the big cats in the state. It also can help focus protection efforts. For although they face threats, the cats have many friends.

The mortality map comes from the University of California, Davis Road Ecology Center. “Road ecology” is an emerging science. In the words of the center’s website:

The UC Davis Road Ecology Center brings together researchers and policy makers from ecology and transportation to design sustainable transportation systems based on an understanding of the impact of roads on natural landscapes and human communities.

The results of the mapping are grim. Road accidents claimed one to two lions every week between 2015 and 2022. A ray of hope, the number has slowly declined, may be illusory. It may show a decline in the total population. A statewide survey of the population is pending.

Kinked tails have shown up in local mountain lions, a sign of inbreeding due to fragmented habitat. Most cats will not even try to cross a freeway and are restricted in their range.

UC Davis has a large veterinary school. Phys,org quoted Winston Vickers, a wildlife veterinarian at the school:

“Regionally, parts of Southern California are especially dangerous for mountain lions, with traffic being the primary cause of death,” Vickers said. “In other areas, direct conflict with livestock results in mountain lions being killed. The two together are clearly bad, especially for small, isolated populations. Busy freeways also cut off mountain lions from potential mates, severely decreasing their genetic diversity and threatening their existence.”

According to the center “particularly problematic” areas on the mortality map 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

There is hope, however. The late P-22 inspired efforts to build a freeway overcrossing above the 101 Freeway in Southern California. CalTrans is now committed to wildlife considerations for all transportaion projects. The California Department of Fish and Wildife

works to preserve cougars. The National Park Service (NPS) has been monitoring cougars in the Santa Monica Mountains for about 20 years and also is involved in rescue efforts

tiger in shallow photo
Tigers also suffer from habitat constriction and are at risk of inbreeding. Efforts such as Liberty Canyon are being studied all over the world. Photo by Richard Verbeek on

Published by ursusrising

long time writer and editor living in Los Angeles

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