What’s Fluffy, Squeaky And Interbreeding In The Rockies? Pikas

Originally published on July 16, 2018 10:32 am

Pikas are fluffy mammals that live at high altitudes across the West. They squeak when danger nears. The squeaky fluff-balls are considered indicators of climate change because they’re so sensitive to heat. Scientists say they have found some of animals in Colorado’s Rocky Mountains are behaving strangely.

Jessica Castillo Vardaro, a wildlife biologist with the University of California, Berkeley, studies pika genetics, a field that can involve some unusual data collection methods.

“We were literally crawling around in the rocks picking up pika poop,” says Castillo Vardaro, who was affiliated with Oregon State University at the time of the study.

Credit Castillo Vardaro et. al. 2018
There are five major lineages of American pika, four of which live in the Mountain West. Their ranges are outlined in black.

Castillo Vardaro says the animals are very territorial, so they tend to stick to themselves, breeding mainly with their neighbors. But based on careful poop analysis, she and her colleagues, writing in the journal PLOS ONE, found that in a small patch of Rocky Mountain National Park, two subspecies of the animals are interbreeding.

She says the hybrid pikas have a different “dialect” than their parent populations. When people or animals get near them, they “bark” and “squeak” a little differently.

But might interbreeding also make the animals more adaptable to rising temperatures?

“We don't know. That’s one of the main questions to come out of this,” says Castillo Vardaro. “It could be a positive, a negative or a neutral process. For example, sometimes hybrid individuals are less well-adapted to the local environments than either of the parent populations were. But there’s also the situation where the hybrids might be more fit to the current or future environmental conditions.”

That’s her next research question.

This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, Yellowstone Public Radio in Montana, KUER in Salt Lake City and KRCC and KUNC in Colorado. 

Correction: A previous version of this story referred to pikas as "rodents." They are lagomorphs, relatives of rabbits and hares.

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