Two Mountain Lions Found Dead In Santa Monica Mountains; Rodenticides Affected Both Of Them

Oct 9, 2019

Two mountain lions have been found dead in the Santa Monica Mountains National Recreation area, bringing the total to five deaths from various causes this year. Biologists studying mountain lions say the latest deaths highlight what’s becoming a growing concern in the region: anticoagulant rodenticides, better known as rat poison, is ending up in the food chain, and killing some of the protected big cats.

The remains of the mountain lion P-30 were found September 9th in Topanga State Park , after its radio tracking caller sent out a mortality signal. It died from internal bleeding, and had multiple poisons in its system.

Seth Riley is a Wildlife Ecologist with the National Park Service. Riley says another mountain lion, P-53, was found dead near Malibu in August, also with evidence of rat poison. The remains were too decomposed to positively say that the chemicals were the cause of death.

Riley says the shocking part is virtually all of the mountain lions they have been monitoring in the region have signs of poison. It’s been detected in 23 of the 24 big cats.

They think coyotes are eating the poisoned mice and rats, and when mountain lions eat coyotes, the rodenticides get in their systems.  The death of mountain lion P-47 earlier this year was also tied to the poisoning.

Two other mountain lions died in the region this year from other causes. One was being chased by another mountain lion when it was struck, and killed when it ran onto the 405 freeway. And, one was shot to death by a man in Simi Valley, who was just sentenced to jail for the killing.

National Park Service researchers have been studying the region’s mountain lions since 2002. They’re currently tracking 10, including six in the Santa Monica Mountains, three in the Simi Hills, and one, the most famous called P-22, which lives in Griffith Park. Riley says despite the recent deaths, the population is stable, as long as we don’t lose a few more.

He says the recent mountain lion deaths emphasize a way area residents can help. Riley urges people with rat and mice issues to find alternatives to rodenticides which are ending up in the mountain lion food chain.