Mountain lions fear humans, fleeing when they hear our voices, new study reveals

Mountain lions fear humans, fleeing when they hear our voices, new study reveals
Mountain lions fear humans, fleeing when they hear human voices. Credit: Sebastian Kennerknecht/

"Fraidy cat" isn't the way most people think of mountain lions, but when it comes to encounters with humans, perhaps they should.

New research into the behavior of these big cats indicates that they don't like encountering humans any more than we like bumping into them on hiking trails. The findings are particularly valuable as human development encroaches on lion habitat and drives up the number of human-puma encounters.

"We exposed pumas in the Santa Cruz mountains to the sound of to see if they would react with fear and flee, and the results were striking: They were definitely afraid of humans," said Justine Smith, lead author of the paper "Fear of the human 'super predator' reduces feeding time in large carnivores," published in the June 21 online edition of the Proceedings of the Royal Society B.

Smith, who led the study as a graduate student in environmental studies at UC Santa Cruz, and her colleagues devised a novel experiment to gauge puma behavior: Her team placed audio equipment at puma kill sites in the Santa Cruz Mountains; when a puma came to feed, its movements triggered motion-activated technology that broadcast recordings of people talking, and a hidden camera captured the puma's responses. They broadcast recordings of Pacific tree frog vocalizations as a control.

"We found that pumas almost always ran from the sound of humans—and almost never ran from the sound of frogs," said Smith, now a postdoctoral researcher at UC Berkeley. In 29 experiments involving 17 pumas, the pumas fled in 83 percent of cases as soon as it heard human voices, and only once upon hearing frogs.

A puma in the Santa Cruz mountains shows no response to the sound of frogs but flees when it hears human voices. Credit: Santa Cruz Puma Project

In addition to establishing the fear response, the study reveals changes in puma feeding behavior that could have implications for their well-being in human-dominated landscapes—and their impact on prey populations, particularly deer. The results build on previous work showing higher kill rates and lower feeding times in more human-populated areas.

"We found that pumas took longer to return to their kills after hearing people, and subsequently reduced their feeding on kills by about half," said Smith. "Those behavioral changes are significant, as our has shown that they cause pumas to increase their kill rates by 36 percent in areas with high human activity."

This is the first study to experimentally link the fear of humans to feeding behavior in large carnivores, said Chris Wilmers, associate professor of environmental studies at UC Santa Cruz and a senior author on the study.

"Fear is the mechanism behind an ecological cascade that goes from humans to pumas to increased puma predation on deer," said Wilmers, a wildlife ecologist who studies the cascading effects large carnivores can have on their prey. "We're seeing that human disturbance—beyond hunting—may alter the ecological role of . As we encroach on lion habitat, our presence will likely affect the link between top predators and their prey."

The experiment was part of a long-term study of puma ecology in the Santa Cruz Mountains that began in 2008. All 17 pumas in this study have housing developments in their home range, and exposure to humans is commonplace. Kill sites were identified with data transmitted from GPS-monitoring collars worn by pumas that have been captured, collared, and released as part of the project. Human voice recordings were broadcast to mimic the natural volume of conversation.

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More information: Fear of the human "super predator" reduces feeding time in large carnivores, Proceedings of the Royal Society B, rspb.royalsocietypublishing.or … .1098/rspb.2017.0433
Citation: Mountain lions fear humans, fleeing when they hear our voices, new study reveals (2017, June 20) retrieved 23 September 2019 from
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Jun 20, 2017
Well sure. The bold ones were repeatedly killed off. Like black bears. Its a form of domestication.

Jun 20, 2017
I don't think so. It's basically a simple case of 'if you hassle a human you are going to die" Cats are not stupid and they do communicate with each other. The same reason most larger predators have learned to stay away from us.

Jun 20, 2017
What about caes where they have attacked humans? Out of fear?

Jun 20, 2017
From what I understand it's normally protecting their young or they are starving. I'm sure there are a few animals out there that don't know what happens but they are an exception instead of the normal these days. About the only animals I know of that don't generally fear humans are crocodile types and possibly a hippopotamus. Just about everything else will leave the area when a human shows up.

Jun 20, 2017
I just hope that no one who reads this acts like an idiot and taunts one of these cats expecting it to run away in fear. Fear can also cause extremely aggressive behavior in animals (including humans) in cases where the animal feels trapped or forced to protect a vital interest.

Jun 21, 2017
What about caes where they have attacked humans? Out of fear?

Cats aren't robots. Just like with a human population there'll always a couple of 'dumb ones' that don't learn.

Jun 21, 2017
Seems like a simplistic confirmation of Genesis 9:2
The fear and dread of you will fall on all the beasts of the earth, and on all the birds in the sky, on every creature that moves along the ground, and on all the fish in the sea; they are given into your hands.

Our everyday experience with just about all fauna bears this out.

Jun 21, 2017
....and of course the reason for that is given in verse 3 where human beings [and animals] are now allowed to forgo their previously pure vegetarian diet and supplement it by eating animal flesh.....

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