Climate Change Could Spell Final 'Chuckle' For Alpine Frog
Across the Western U.S., yearly areas of snowpack are decreasing, and researchers are trying to figure out what that means for everything that relies on the snowmelt — from farms to power plants to a little creature known as the Cascades frog.
The frog lives way up in the mountains of the Northwest and thrives in alpine wetlands fed by melting snow. Scientists are now trying to figure out how these frogs will adapt to their shrinking habitat.
In Washington's Olympic Mountains things are looking dryer than normal. On a recent day, Maureen Ryan is out looking for the wet spots. She's a researcher with the University of Washington and an expert on amphibians that live at high elevation.
These mountain trails are Ryan's lab, so to speak. She studies tiny snow-fed potholes of water, cupped in the folds of high mountain ranges in the Northwest, a perfect habitat for Cascades frogs. But as the global climate warms, that habitat is receding.
"What's happening to these frogs is in no way dissimilar to what's happening to us, even if we can't necessarily see it," Ryan says. "These frogs are reliant on snowmelt for the water they need to live."
People in the Pacific Northwest also rely on snowmelt to supply water for agriculture, industry, hydropower and drinking water.
Cascades frogs spend most of the year beneath dozens of feet of snow. But for a few short months in the summer, the frogs come to warm sunny ponds to feed and mate. While they're at it, they make what some describe as a "chuckling" sound.
The team fans out, squelching through the muck and slowly scanning the water for the signature dappled brown and yellow heads of the frogs. Most of them are about the size of a child's hand. Their bug eyes peer out from beneath the shelter of the banks.
After the scientists have circled the pond and caught about 30 frogs, they pull out a device called a pit tag reader that looks like the scanner at the grocery store check out
"It just detects whether there's a pit tag under the skin of the frog and if there is it gives us a number for that individual frog," Ryan says.
The team has been inserting tiny magnetic tags, each about the size of a grain of rice, beneath the skin of these frogs for more than a decade. It doesn't harm the frogs. Some of the frogs caught on this day do have tags.
"So we have some frogs that we've caught that we know are 13,14 years old and might be older. It's pretty amazing," Ryan says.
Along with their frog scanning, Ryan's team monitors the temperature and depths of the ponds where the frogs are caught. They want to find out when they're drying up during the course of the summer and what that means for the frogs.
"Last year we had a good number of ponds ... [that] dried up before the tadpoles had metamorphosed, so they didn't survive there," she says.
Ryan worries that with less snowpack and hotter summers, more egg sacks and tadpoles will be stranded out of water. That could ultimately decimate the population, unless they can move into deeper alpine lakes that are more resilient to the warming climate.
The problem there is that many of those lakes have been stocked with trout for recreational fishing, and the trout find the Cascades frog delicious.
"These ponds the frogs live in are kind of a microcosm of what's going on in the West," Ryan says. "Most of the American West gets its water from snowmelt, and that runs our agricultural system and our energy system, our tap water, our industry — all of those things."
The Pacific Northwest has lost about 50 percent of its snowpack over the last 50 years. In the future, sounds like "chuckling" of the Cascades frog could become even harder to hear.
This story is part of KUOW's EarthFix project.
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