Study: Mountain lions reduce roadway deer collisions by 67%

Scientists in Washington state found a little-studied benefit to the presence of mountain lion populations near roadways.

1 minute read

August 10, 2026, 8:00 AM PDT

By Diana Ionescu @aworkoffiction


Mountain lion in a forest.

Mountain lion. | Danita Delimont / Shutterstock

A study from Washington state shows that the presence of mountain lions can have a major impact on the number of deer-car collisions on area roads, reports Chris Pugh in M Live.

"The research, published Aug. 5 in the journal Current Biology, examined puma and deer activity across Washington’s Olympic Peninsula. Scientists concluded that deer modify their behavior when pumas are nearby, leading them to spend less time near roads and become more active during daylight hours, cell.com said." The study estimates that puma activity was associated with a 67% drop in the probability of deer collisions and a 76% drop in the total expected number of crashes over a five-year period. "The findings suggested deer were 15% less likely to be found near road-dense areas and were more likely to remain in remote habitat when pumas occupied the landscape."

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