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 human voices 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 21st 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. 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.
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 large carnivores. As we encroach on lion habitat, our presence will likely affect the link between top predators and their prey.”