Big Chill Helps Mountain Yellow-Legged Frog

One of the most endangered amphibians in North America—the mountain yellow-legged frog—might have some hope this spring due to the collaborative work of researchers at the San Diego Zoo’s Institute for Conservation Research, along with the help of biologists at the U.S. Forest Service, U.S. Geological Survey, and the U.S. Fish and Wildlife Service.

Courtesy of UC Berkeley, www.crcd.org

As reported in the Press-Enterprise (Riverside, California), researchers from the San Diego Zoo’s Institute for Conservation Research, which has a captive breeding program for the frogs, discovered that three months hibernation in near-freezing water is what gets these frogs in the mood for love. In the wild, frogs hibernate in icy, high-elevation streams, not in 55-degree aquariums. To mimic these cool temperatures, they were placed in clear plastic shoe boxes called “Valentine’s Day retreats” and stored in the refrigerators.

When they were removed from the refrigerators in April, they displayed breeding behavior within a few days. According to the institute’s Research Coordinator Jeff Lemm, “It has been wildly successful, and as a result, we could reintroduce about 500 eggs into the San Jacinto Mountains.”*

Only 200 individual mountain yellow-legged frogs exist in the wild. Once common in Southern California’s mountain streams, the frog species is almost extinct due to fungal infections, pollution, habitat loss, and predatory trout introduced for fishing. Researchers hope to re-establish wild populations with the captive-bred frogs.

Kudos to students, researchers, and biologists who are helping to save the mountain yellow-legged frog from extinction!

Please see the video below to learn more about efforts to save the mountain yellow-legged frog. This frog species was also featured in the episode Yosemite in the recently rebroadcast PBS documentary The Thin Green Line, about the amphibian decline, which you can watch online.

*As reported on the University of California’s Natural Reserve System site.