SAVING THE SIERRA NEVADA mountain yellow-legged frog

The mountain yellow-legged frog was once the most abundant amphibian in the Sierra Nevada Mountains. Only a few decades ago, it was difficult to walk around many of the Sierra’s alpine lakes without tripping over these diminutive “mountain gnomes.” Today, the hardy survivors of freezing Sierra winters are vulnerable to a host of modern threats, which have driven the frogs extinct in more than 93 percent of their old Sierra home.

The mountain yellow-legged frog adapted to high-elevation habitats without aquatic predators. Thus, it’s not surprising that the primary reason for the frog’s decline is the introduction of nonnative trout to high Sierra lakes by the California Department of Fish and Game. These stocked fish prey upon tadpoles and juvenile frogs, and scientists predict that the yellow-legged frog could be extinct in the Sierra within decades. Since the Center filed a petition to add the species to the endangered species list in 2000, the National Park Service and U.S. Forest Service have begun removing nonnative trout from some high Sierra lakes in an attempt to restore yellow-legged frog populations. But nonnative trout introductions and frog declines continue, and the Center is challenging the state’s harmful fish-stocking practices.

Although the frog has disappeared from the vast majority of known historical locations — and most of the largest remaining populations have recently collapsed — the U.S. Fish and Wildlife Service continues to refuse to protect the species under the Endangered Species Act. The Service instead placed the frog on the candidate list , a regulatory purgatory that offers no substantive protections. The Center is working to gain full Endangered Species Act protection for the frog. Through our Pesticides Reduction Campaign, we're also pushing the Environmental Protection agency to protect this frog and other imperiled species from toxic pesticides, which can act as environmental stressors that intensify disease, including a fungus that has recently ravaged many yellow-legged frog populations.