🌅 Mountain Lions Are Keeping Roads Safe

SOURCE

Suraci et al. (2026)

WHAT TO KNOW

• A new study by researchers at the conservation nonprofit Conservation Science Partners found the presence of mountain lions is associated with a 67% reduction in the likelihood of deer-vehicle collisions and an estimated 76% decline in the overall number of such collisions. The authors say their work suggests increased road safety can be viewed as another highly valuable ecosystem service provided by mountain lions’ predation, along with well-established benefits like population control, food stabilization, and biodiversity maintenance.

WHY IT MATTERS

• The researchers found that when mountain lions—a.k.a. pumas, cougars, or panthers—were present on Washington’s Olympic Peninsula, deer ventured deeper into the woods, avoiding “habitat edges” like roads and the outskirts of towns and thereby reducing deer-vehicle collisions. The authors believe deer’s behavioral shift around mountain lions makes sense given the way the cats hunt. As “ambush predators,” mountain lions prefer fragmented habitats, like low-density housing developments or roads cutting through forests, since the settings allow them to conceal themselves and attack deer foraging at the edge of forests. Deer were also less active at night when mountain lions were around, reducing their presence at a time of day when deer-vehicle collisions often happen. That shift also made sense to the researchers, since mountain lions primarily hunt at night.

CONNECT THE DOTS

• Previous research has uncovered another effective strategy for reducing deer-vehicle collisions: ending the biannual “spring forward, fall back” by maintaining daylight savings year-round. A 2022 study found the switch from daylight savings each year is linked to a 16% increase in deer-vehicle collisions in the week after clocks are changed. The researchers estimated maintaining daylight savings year-round would prevent 33 human deaths, 2,054 human injuries, and 36,550 deer deaths each year, while also saving around $1.2 billion in vehicle collision costs.