Mountain Lions Reduce Deer-Vehicle Collisions by 67%, Study Finds
A research article released on August 5 in Current Biology indicates that mountain lions (also known as pumas, cougars, or panthers) play a crucial role in decreasing deer-vehicle accidents. Investigations conducted on the Olympic Peninsula in Washington showed that the presence of pumas resulted in a 67% reduction in the likelihood of collisions and a 76% decrease in incidents over a five-year period. Data collected from 503 camera trap locations and 59 GPS-collared pumas between July 2020 and June 2025 demonstrated that deer exhibited increased daytime activity in the presence of pumas. The study documented 953 accidents, which led to two fatalities, over 80 injuries, and incurred costs of $14.7 million, with deer responsible for 92% of these incidents. Experts commended the research, emphasizing the ecological benefits provided by mountain lions.
Key facts
- Study published August 5 in Current Biology
- Presence of pumas linked to 67% drop in deer-vehicle collision likelihood
- 76% overall decline in crashes over five years
- Study site: Olympic Peninsula, Washington state
- Data from 503 camera trap sites and 59 GPS-collared pumas (July 2020–June 2025)
- Partnered with five Native American communities
- 953 total crashes mapped, resulting in 2 human deaths, 80+ injuries, $14.7 million in costs
- Deer responsible for 92% of accidents
- Deer avoided habitat edges and were more active during the day when pumas present
- Pumas are ambush predators that prefer fragmented habitats
- Experts: Liana Zanette (Western University), Justin Suraci (Wildlife Conservation Science), Fraser Shilling (UC Davis)
- Potential ecosystem service extends beyond study area
Entities
Institutions
- Current Biology
- Western University
- New Scientist
- Wildlife Conservation Science
- Wired
- University of California, Davis
- SFGate
- Popular Science
- Smithsonian Magazine
Locations
- Olympic Peninsula
- Washington
- United States
- Puget Sound
- Seattle
- Canada
- Americas