Squirrels are climbing high to escape global warming

For animals in the Rocky Mountains, global warming is literally an uphill battle. A long-term study from CU Boulder has revealed that golden-mantled ground squirrels, along with many other small mammals, are climbing higher into the mountains to escape unsuitably warm temperatures.

Study lead author Christy McCain is an associate professor in the Department of Ecology and Evolutionary Biology and a curator of vertebrates at the CU Museum of Natural History.

“It’s frightening. We’ve been talking about climate change in the Rockies for a long time, but I think we can say that this is a sign that things are now responding and responding quite drastically,” said Professor McCain.

The golden-mantled ground squirrel is a popular sight among tourists that has an appearance similar to a chipmunk. The squirrels live in conifer forests in the Rockies and several other western mountain ranges.

“It is likely one of the most photographed mammals in Rocky Mountain National Park as it poses and preens on rocks near the roadside and in campgrounds,” said Professor McCain. “They hibernate in winter, are territorial in the summer, and they make distinctive alarm calls to notify each other of nearby dangers.”

The research was focused on nearly 50 species of small mammals located in the Front Range and San Juan Rockies, including mice, shrews, and even the yellow-bellied marmot.

The experts determined that the ranges of these small mammals have shifted by an average more than 400 feet up in elevation since the 1980s. Meanwhile, the ground squirrels and other “montane mammals” which already live at higher elevations have shifted by up to 1,100 feet.

According to the researchers, this trend could squeeze many animals out of Colorado altogether. Professor McCain said that the small mammals may be bellwethers for larger and increasingly urgent changes in the Rocky Mountains.

“I was expecting that we would see something between 100 to 200 meters, but we saw a lot more. This is way bigger than the change that has been determined in other mountain regions around the world.”

According to Professor McCain, the study paints a stark picture of a mountain range in crisis. The good news is that there may still be time to reduce greenhouse gas emissions to protect the animals and natural landscapes.

“It’s a wake-up call,” said Professor McCain. “We have to start taking this seriously immediately if we want to have healthy mountains and ecosystems.”

The study is published in the journal Ecology.

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By Chrissy Sexton, Earth.com Staff Writer