Amphibians and fish occur at all elevations within Sequoia and Kings Canyon National Parks. You may see some species only seasonally while others may be found at all times of the year. Their occurrence ranges from common (Pacific treefrogs) to extirpated, or locally extinct (foothill yellow-legged frogs).
Mountain Yellow-legged Frogs and Nonnative Fish
From 1870 to 1988, nonnative trout were introduced to high-elevation lakes and streams to make these areas more attractive to anglers. The introduction of fish has had many unintended effects - the most dramatic being the resulting decline in mountain yellow-legged frog populations due to fish predation of frogs and tadpoles and the insects they feed on. Although once lumped together as a single species, mountain yellow-legged frogs have been split into the southern mountain yellow-legged frog (Rana muscosa) and the Sierra Nevada yellow-legged frog (Rana sierra). Both species occur within Sequoia and Kings Canyon National Parks and have disappeared from most of their native range. In 2014, they were listed as endangered under the Endangered Species Act. Although the introduction of trout into frog habitat is still considered a major cause of historic and current declines, the recent epidemic of amphibian chytrid fungus (Batrachochytrium dendrobatidis) has resulted in a another wave of population crashes, and appears to be the primary threat to the remaining populations of frogs occupying fishless habitat.
Visit the Giving Mountain Yellow-legged Frogs a Fighting Chance page to learn more about efforts to restore populations of these frogs to some of the parks' lakes and watch a short video about this project.