Quirks and Quarks

Scaredy-cat cougars frightened into killing more prey

People aren't just predators to cougars but "super predators" who strike fear in the cats at the top of the food chain. The big cats get so afraid of our sounds that they stop feeding on deer they've killed, an effect that cascades through their food chain.
A cougar in a tree in California. (Chris Dairmont)

While the sharp teeth and dagger-like claws of cougars scare us, it turns out we scare the massive cats even more. Just the sound of a human voice puts these fraidy-cats off their dinner. 

Dr. Liana Zanette is a biology professor at Western University. She and colleagues at Western, working with researchers from the University of California Santa Cruz to gauge how the predators respond to played sounds of people talking or frogs chirping as a control.

Videos show cougars, also called mountain lions and pumas, high-tailing it away from their kills as soon as they hear a human voice.

A cougar with its cached kill from one of the scientist's video recordings. (Liana Zanette)

"They perceive us predators and there are ecological consequences," Zanette said. "They stop feeding."

The researchers found cougars fed on their deer dinners for half as long after hearing humans than when they hear neutral frog calls.  But because they abandoned their kills - they had to go and kill more prey to ensure they received enough food.

"They're feeding less so they have to kill more because people are scaring them off their caches. And we know that responses of middle- of-the-food-chain animals to their predators has effects further along the food chain and that is certainly the case for deer."

The findings reflect just how scary we human "super predators" are to cougar predators, the researchers say. Humans kill carnivores as much as nine times their natural predators do.

But people also tolerate large carnivores all over the world, Zanette said. What the fear response means for large carnivores still needs to be sorted out as people and predators overcome their tension in increasingly human-dominated landscapes. 

Cougar reacts

6 years ago
Duration 0:11
Watch how a cougar responds to frog and human sounds at its kill site.