One of the most distinctive sounds in mountainous regions of the Northwest is the territorial honk of the American pika. Their call kind of sounds like a duck accidentally ate a dog’s squeaky toy.
Climate change has long been considered a threat to the small mammal.
“We’ve long suspected that the American pika… [was] vulnerable to changing climate. So we wanted to dig in to learn more about what kinds of factors were pushing them towards extinction,” says National Park Service Ecologist Tom Rodhouse, co-author of the study.
New research confirms the threat of climate change is already playing out for pikas in some of the parks studied. But in others, local factors on the ground - like geology, weather, elevation and genetic diversity of the population – make the outlook for long-term survival much more positive.
Over the course of five years, researchers did pika counts at eight national parks and monuments. They then used that population data to predict how they would fare in the future, based on climate change and those other local, on-the-ground factors.
One factor determined whether pikas at certain parks survived or didn’t was how climate change effected something scientists call “habitat connectivity.”
Picture a population of pikas living across several mountains. With climate change, parts of that landscape experience shifts in things like vegetation and temperature, making it unsuitable for pikas.
It also can fragment continuous stretches of good habitat. This is a problem because pikas don’t tend to travel, says Oregon State University’s Doni Schwalm, who co-authored the paper.
“The populations become so isolated that they can’t reach other. And once one blinks out, there’s no way for them to be repatriated – for other pikas to move in,” she says.
Consequently the population is lost.
Schwalm said habitat connectivity played a major role in their analysis of Rocky Mountain National Park. Their models predicted that pikas would be eliminated from that park within 80 years.
Connectivity was a major issue for Crater Lake National Park as well. The research says half the park’s pika population will be lost.
Schwalm says understanding more about the local factors and how they interact with climate change could help park managers direct conservation efforts.
“In looking at different populations, some are less vulnerable than others. And some probably no matter what we do, there’s not going to be an opportunity to conserve that particular population, so perhaps it means that you invest elsewhere,” she says.
The research is published in the journal Global Change Biology.