Two decades of studying mountain lions has provided researchers with a wealth of information. Regarding mountain lion mortality, we’ve learned that anticoagulant rodenticide poisoning (rat poisons) is one of the leading causes of death.
Researchers believe mountain lions are exposed through secondary or tertiary poisoning, meaning that they consume an animal that ate the bait, such as a ground squirrel, or an animal that ate an animal that consumed the bait, such as a coyote.
Twenty-eight out of 29 mountain lions tested in the study have tested positive for one or more anticoagulant compounds and seven have died from anticoagulant rodenticide poisoning (as of December 2021).
Other major causes of death in mountain lions include intraspecific strife (mountain lions killing other mountain lions) and vehicle strikes.) Since 2002, at least 32 mountain lions (collared and uncollared) have been killed by vehicles on the many busy roads, highways, and freeways in the region (as of December 2022).
Click on the links below to learn more about the more notable mountain lion deaths.
P-015 (the first case of poaching); P-038 (this cat was illegally killed when it was shot in the head)
P-009 (the first roadkill of a radio collared mountain lion in the study);
P-018 (this cat’s dispersal path led him to the 405 Freeway and getting hit by a car near the Getty Center on-ramp); P-061 (this cat was the first GPS radio collared mountain lion to cross the 405 Freeway but he was killed several months later in the same section of the freeway when trail camera footage showed him being chased by another mountain lion on the east side of the 10-lane highway); Other road mortality deaths include: P-023, P-032, P-039, P-049, P-051 and P-052, P-078
P-030 (this cougar died of rodenticide poisoning); P-034’s (this cat’s death marked the study’s third case of mortality directly from rodenticide poisoning); P-047 (lab results indicate this cat may have succumbed to rodenticide poisoning); Other anticoagulant rodenticide-related deaths include: P-003, P-004, and P-076
P-022 (this cat was captured by California Department of Fish and Wildlife due to a sudden change in his behavior and unfortunately euthanized upon poor health evaluation results); P-056 (this cat was killed under state depredation law in 2020); P-074 (his last GPS point was recorded the same day the Woolsey Fire moved into the central portion of the Santa Monica Mountains. He likely succumbed to the fire).