Rat poison detected in P-54, her unborn mountain lion kittens after she was struck and killed by car

For the first time, biologists studying the native mountain lion population in the Santa Monica Mountains have found rat poison in the unborn fetuses of a female mountain lion fatally struck by a car earlier this year.

P-54, who was struck and killed by a car on Las Virgenes Road between Piuma Road and Mulholland Highway on June 17, was pregnant with four kittens when she died, according to the National Park Service. She was taken to the California Animal Health and Food Safety Lab in San Bernardino for a necropsy and testing, which determined she died of traumatic injuries, including multiple fractures to the ribs and left femur.

But other tests showed that anticoagulant rodenticide compounds were found in her liver and the neurotoxic rodenticide bromethaline was detected in her abdominal fat tissue. The four full-term kittens P-54 was pregnant with also tested positive for the same rat poisons.

"This is the first time during our 20-year study that we've been able to test mountain lion fetuses for anticoagulant rodenticides," NPS biologist Jeff Sikich said in a statement.

The finding shows that mountain lions in the Santa Monica Mountains are not only in danger from vehicles, but also the use of rat poison. Researchers have now documented the presence of rat poison in 39 out of 40 local mountain lions tested, included the four fetuses, according to the NPS.

"Unfortunately, we've learned that mountain lions are susceptible to rat poisons even before they are born," Sikich said. "In this case, it is also unfortunate because the death of P-54 from a vehicle resulted in the loss of four other young mountain lions, two males and two females, that were about to enter the population."

A number of big cats have been found dead from rat poison in the Santa Monica Mountains, including P-30, P-53 and P-76 who were both found to have died from internal bleeding and a bobcat that was found to be extremely emaciated with signs of chronic anemia. Gov. Gavin Newsom last year signed a bill into law banning certain toxic rat poisons, but biologists say the results from P-54 and her kittens show exposure continues to be a problem in wildlife in and around the park.

The region's mountain lions are experiencing an "extinction vortex," according to the Center for Biological Diversity, caused in part by rodenticide poisoning and roads restricting their movements, which has led to the species showing signs of severe inbreeding.

"The devastating death of P-54 and her four unborn kittens is a morbid reminder that we are driving our beloved pumas toward extinction," Tiffany Yap, a senior scientist at the Center for Biological Diversity, said in a statement.