Project goal: Use cutting-edge techniques to study and protect three vulnerable species: Yosemite toads, Sierra Nevada yellow-legged frogs and California red-legged frogs.

Why this work matters: Amphibian populations are declining worldwide, as habitats vanish or deteriorate, and invasive diseases and species arrive. In Yosemite, those same factors threaten three at-risk species: Yosemite toads, Sierra Nevada yellow-legged frogs and California red-legged frogs.

With support from our donors, though, the park has pushed to the forefront of amphibian science and conservation, with notable success. Scientists have seen yellow-legged frog numbers increasing, after years of carefully moving the endangered amphibians to healthy lake habitat; have increased their understanding of Yosemite toad populations, including the toads’ vulnerability to climate change; and have released hundreds of red-legged frogs in the Valley.

In 2020, the park’s aquatic ecologists built on prior amphibian research and restoration efforts, with a focus on two key ongoing issues: chytrid fungus, which can be deadly for amphibians, and habitat availability. With your support, the team set out to:

  Identify chytrid infections in yellow-legged frogs and Yosemite toads, using a highly accurate rapid-response test to enable quick detection and intervention in the field.

  Move yellow-legged frogs to healthy, restored habitat in high country lakes.

  Monitor recently released yellow- and red-legged frogs, using field surveys and microchips to keep an eye on how the frogs move through and use different habitats.

How your support helped: Your support helped biologists continue working to ensure Yosemite’s native frogs can thrive in healthy ecosystems. Biologists released dozens of Sierra Nevada yellow-legged frogs in high country lakes; transported tadpoles to a special facility at the San Francisco Zoo, where they will be raised safely before being reintroduced in the park; monitored California red-legged frogs in Yosemite Valley; and more. This work helps researchers gather information and hone techniques that can help protect amphibians within and beyond the park.

Project partners: Yosemite National Park and University of California, Santa Barbara.

Rob Grasso

Aquatic Ecologist, Yosemite National Park

Project Notes

"Yosemite is one of the only areas of the world where amphibian populations are increasing as a result of adaptive management."