High mountain alpine lakes, like this one in the Emigrant Wilderness. once had thriving populations of the Sierra Nevada Yellow legged frog. Now the frog is all but gone from most of these places due to a variety of impacts to its natural habitat.

2/7/12    

     For years CSERC has been urging the US Forest Service to take action to protect the declining population of the once abundant Sierra Nevada yellow-legged frog (SNYLF). CSERC's concerns originated over a decade ago. When the Center's staff did their annual high mountain meadow surveys, they noted that the numbers of the SNYLF observed were significantly less from season to season.

     Staff began to conduct systematic field surveys for the frog as part of their fieldwork. Building upon the information staff was gathering CSERC began to advocate with other groups, including the Center for Biological Diversity, for protection of the SNYLF and its habitat.

       The most significant impacts to the frog that people have the ability to control, are stocking (by the California Department of Fish and Game) of non-native trout species to alpine lakes, and pesticide drift from Central Valley polluting the lake water. The alpine lakes where the SNYLF are found have little shelter for the frogs and their eggs to hide from the non-native trout, making them especially vulnerable. Pesticide drift from Central Valley farms also is viewed as a problem that can be readily addressed, and reduction of pesticides in alpine lake water is important to the recovery of the species.The introduction of the Chytrid fungus (a fast spreading fungus that is decimating amphibian populations globally) and livestock grazing degrading meadow and streambank integrity- also contribute to the reduced ability of the SNYLF to survive and reproduce. Population numbers are estimated to have declined by more than 50%.