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Save The Frogs Day: April 25th, 2015

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Mountain Yellow-Legged Frog
Rana muscosa

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The Sierra Nevada mountain range in California and Nevada is home to some of our country's most spectacular geography, including Yosemite Valley, Mount Whitney (the highest point in the contiguous United States) and Lake Tahoe (the largest alpine lake in North America). The Sierras are also home to the Mountain Yellow-Legged Frogs (Rana muscosa), which are found in creeks, lakes, and sunny riverbanks at elevations from 370m to 2,100m.

The closely-related Sierra Nevada Yellow-Legged Frog (Rana sierrae) and the Southern Mountain Yellow-legged are important for an intricate food web—eating large quantities of insects, which may carry human diseases, as well as serving as a food source for snakes, birds, beetles and butterflies. These frogs are two and a half inches as adults. Their abdomens and the undersides of their hind legs are yellow-to-orange, and their backs are yellow-to-reddish, with dark brown or black blotches.

Males develop small, glandular growths (nuptial pads) on the base of their thumbs to help them hold females during mating season. They have adapted to survive in environments that are too cold for most amphibians. Both species are highly vulnerable to the deadly chytrid fungus which has spread through the Sierra Nevada in the past decade, decimating frog populations.

The Yellow-Legged Frogs are highly aquatic, depending on the clear, cool waters of mountain lakes and streams for their survival. Their habitat is undergoing manmade changes that threaten their survival. Non-native trout have been introduced into the fishless mountain lakes. These trout are voracious predators of tadpoles and can eat frog populations to extinction.

Pesticides from California's Central Valley may also contribute to the
species' decline. The windborne chemicals accumulate in the high
mountains and pollute streams and lakes. Frogs have permeable skin
that easily absorbs toxic chemicals, which makes them especially
vulnerable. Frogs are indicators of environmental stress; their health
is indicative of the health of the biosphere as a whole.

One of the simplest and most impactful things we can do is to stop using pesticides and choose organic foods whenever possible. We need to urge the California Fish and Wildlife Department to stop stocking high mountain lakes with non-native fish where the Mountain Yellow-legged frogs already exist. Individuals can also support organizations, including SAVE THE FROGS that are working to save these species from extinction by bringing awareness to their plight and educating the public about the importance of frogs and their habitats.

Photo of Rana muscosa courtesy Kris Ratzlaff

Video: Releasing Yellow-Legged Frogs Into The Wild

In this SAVE THE FROGS! Academy video, SAVE THE FROGS! Founder Dr. Kerry Kriger and Frank Santana of the San Diego Zoo discuss California's critically endangered Mountain-Yellow Legged Frogs. Please watch it and learn ways YOU can help us save these critically endangered frogs.


"Hi Dr. Kriger, I just wanted to convey to you how much I enjoyed and benefited from this afternoon's seminar on the Rana muscosa. It was very informative and inspiring. Increasingly, these sorts of initiatives are the only hope we have left for saving many frog species, and indeed, much of our planet's biodiversity. Thanks again for hosting the webinar." -- David S. Price, LEAD Asia Senior Environmental Consultant, Arcata, CA

"Thanks Kerry! I had a great time doing this. Thanks for all the work you all do at STF to inform and inspire the public to conserve amphibians and their environment!"-- Frank Santana, San Diego Zoo

Read this report Water Woes 2012, which features a section we wrote about the plight of the Mountain-Yellow Legged Frogs.

Rana muscosa