New pika behavior reveals adaptation to human presence

April 1, 2017 - 8:30am

Study finds that voice modulation helps the small mammals avoid unwanted attention

Nature is singing a new tune, and if you're an Oregon hiker, you might catch an earful this summer. A recent Oregon Zoo study reveals that a local population of pikas — small cousins of the rabbit — has adapted to the heavy hiker traffic through its habitat by altering the pitch of its distinctive, squeak-toy-like call.

The new vocalizations, dubbed "selfie-response grunt" by conservation biologists, were observed whenever hikers stopped mid-trail to take photos or video of the small mammals.

"The pikas are actively deterring their admirers by issuing this rather disturbing call," said David Shepherdson, deputy conservation manager at the zoo. "The sound is a bit reminiscent of an angry, elderly man experiencing chest pain or gastro-intestinal distress."

Dr. Shepherdson, who led the zoo study, suspects the unusual call might have been learned from a neighboring screaming marmot. The effect, he said, has triggered a shift in human behavior.

"We found that, following a salvo of pika grunts, most hikers immediately lowered their phones and became visibly upset," Shepherdson said. "They would then continue along the trail, and the pikas would return to gathering vegetation for their food caches."

Shepherdson said the new findings contradict recent reports that pikas might be through with evolutionary adaptations — and offer a hopeful sign for this sentinel species, whose typically high-altitude habitat makes it especially vulnerable to rising global temperatures. Columbia Gorge pikas are the lowest-elevation pikas in the U.S.