Pumas slash US road‑deer collisions by 76% in Washington study

A study published in *Current Biology* examined vehicle‑deer crashes on the Olympic Peninsula in Washington State. Researchers found that areas with resident pumas (mountain lions) experienced 76 % fewer collisions between cars and black‑tailed deer compared with puma‑free zones. The reduction is attributed to behavioral changes: deer avoid roads, spend more time in forested areas and are more active during daylight, rather than a decline in deer numbers.

Human impacts were notable. Between July 2020 and June 2025, two people were killed and more than 80 injured in deer‑related crashes on the peninsula, with total medical and property costs of about $14.7 million. Nationwide, 1.8 million wildlife‑vehicle insurance claims were filed in 2022‑23, and over 200 people died in such incidents that year. The study’s lead author, Justin Suraci of Conservation Science Partners, warned that “the number of deaths and injuries would be honestly larger if all pumas disappeared.” More than 1,000 pumas are killed annually by authorities in the western United States.