Mountain yellow-legged frogs were ubiquitous and abundant in Sierra Nevada lakes, ponds, and streams, prior to the introduction of non-native predators (trout) and emergence of infectious disease (the amphibian chytrid fungus). Although wildlife managers have restored some frog habitat to the historic fishless state and frogs have responded positively, mountain yellow-legged frogs continue to decline due to disease. Over almost two decades, our research has documented the spread of this disease and its impacts on mountain yellow-legged frog populations throughout the Sierra Nevada. More recently, our research focus has shifted to developing tools to help frog populations recover despite the presence of disease. These include translocations of disease-resistant frogs, captive rearing, and treatment of disease in the field. Success with some of these tools give us hope that mountain yellow-legged frogs will continue to occupy Sierra lakes, well into our future.

photo credit: Roland Knapp