Mountain lions slash road collision deaths in Washington and California

A new study shows that the presence of mountain lions (pumas) sharply reduces deer and elk vehicle collisions. Researchers analyzed data from 503 camera traps and 59 GPS‑collared pumas on Washington State’s Olympic Peninsula between 2020 and 2025, finding a 76 % drop in deer‑vehicle crashes where pumas were common. The study, published in *Current Biology*, notes that deer are involved in more than 1.5 million U.S. collisions each year, causing over 200 deaths and billions of dollars in damage.

Similar findings were reported for California, where mountain lions’ hunting of deer appears to lower the risk of road accidents. Conservation Science Partners’ Justin Suraci called the safety benefit “undeniable,” and Panthera’s Mark Elbroch said pumas “scare” prey away from roads, reducing collisions without needing to kill the animals. The research suggests that large predators provide valuable ecosystem services that can improve human road safety.

The results could influence wildlife management and road‑safety policies, highlighting the indirect human health benefits of preserving apex predators in North‑American landscapes.