On Monday, the National Park Service announced a significant loss to a small group of mountain lions in California’s Santa Monica Mountains National Recreation Area. P-56, an adult male cat, was killed by a local landowner under the state’s new depredation law. He was presumed to be the father of several other animals who are part of a group the NPS has been tracking for nearly 20 years.

“The loss of a breeding male is a concern for the study, especially when the population is already very small,” Jeff Sikich, the park service’s lead field biologist for the project, said in a press release.

Other conservationists were more blunt. “We are in a dire situation,” says Beth Pratt, the leader of the Save L.A. Cougars campaign and regional executive director at the National Wildlife Federation. “P-56 was one of only two known, or collared, males within the region, and we just took him out. What if the other male gets hit by a car tomorrow?”

When a mountain lion attacks livestock or pets, California laws allow property owners to kill the animal, with a permit, but in 2017, the California Department of Fish & Wildlife (CDFW) made an exception specific to the threatened populations in the Santa Monica and Santa Ana mountains. The so-called “three-strike” policy requires property owners to use non-lethal means to deter a mountain lion that has attacked pets or livestock. However, if the same cat is responsible for three depredation incidents, the state can grant a land owner a lethal permit for the animal. The incidents involving P-56 took place outside the area covered by the policy, but, according to CDFW, the property owner, who lost 12 animals in nine separate incidents, took several deterrent measures before P-56 was killed.

Pratt said that she and other conservationists wish they had a chance to help these property owners implement effective measures, so that lethal action could have been avoided.

Los Angeles is one of only two megacities in the world that has big cats living within the city limits, giving researchers the opportunity to monitor how these at-risk predator species adapt to increasingly urbanized and fragmented habitats. The Santa Monica Mountains are surrounded by the 101 Freeway to the north, the Pacific Ocean to the south, and highways and development to the east and west, creating an isolated environment for this group of mountain lions, who face possible extinction.

The three-strikes policy is aimed at helping Southern California’s most threatened big cat populations that have struggled in recent years because of habitat loss and inbreeding (a result of being cut off from other groups of mountain lions). But it appears those efforts aren’t doing enough. In the last year, several members of this community, including at least four adult males, have died or been killed. P-61, a male born in 2015, was killed while trying to cross the 405 Freeway. P-38, a male born in 2012, was illegally shot in the head. A male born in 2013, P-30, died from rat poisoning, which is also suspected to have caused the death of P-47, a male born in 2015, last March.

The recent deaths pose a grave threat to a group already lacking genetic diversity. In one illustrative example of the claustrophobic conditions: the mother of P-56’s four potential offspring (P-70, P-71, P-72, and P-73) is also his grandmother, P-19. (She’s the same animal known to the Park Service as the Selfie Cat because she appears to pose for a game camera.) The long-term survival of the cats depends on their ability to mingle with other groups in order to maintain the population’s overall health.

A wildlife corridor currently in the design phase, would include a bridge over the freeway to allow the Santa Monica mountain lions to reconnect with surrounding habitats and other cougar populations. Many see it as an integral part of the solution, a sterling example for other species threatened by urbanization and habitat fragmentation. Fundraising for the $87 million project is well underway, and organizers hope construction will be completed by the end of 2023.

However, an overpass may not have precluded the death of P-56. A mountain lion’s nature is to attack prey, but NPS, CDFW, and other conservationists say that attacks on domestic animals can often be avoided when simple precautionary measures are taken, including using properly trained guard dogs and keeping livestock in predator-proof enclosures at night.

To prevent conditions like those that lead to the death of P-56, Pratt says, “we have to fix this coexistence issue. And the good news is: it’s possible. These are not hard fixes.”

Editor's Note: This story has been updated to clarify the agency that investigated the incident and the extent of the property owner's deterrent measures.