U.S. Fish & Wildlife Service

Sacramento Fish & Wildlife OfficeServing the people, conserving the fish, wildlife, and plants of California

A Unit Of The Pacific Southwest Region

Site Visit Insights from Josh Hull and Jennifer Norris

February 7, 2019

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Photo of Jennifer Norris and Josh Hull
Jennifer Norris (field supervisor) and Josh Hull (division chief) work in the Sacramento Fish and Wildlife Office. Photo credit: Rachel Mazur.
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Photo of people observing in the wilderness
SFWO's Josh Hull visits release site for California red-legged frogs with Yosemite National Park staff. Photo credit: Jennifer Norris, USFWS.
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Photo of a California red-legged frog.
The California red-legged frog was reintroduced to Yosemite National Park in 2016 after disappearing for half a century. Photo credit: USFWS.
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Photo of frogs belly in a persons hand
The California red-legged frog is named for its colorful legs and belly. Photo credit: USFWS.

Site visits are critical to helping Sacramento Fish and Wildlife Office (SFWO) biologists learn more about species and their habitats. The trips often take them into areas most people do not have a chance to explore, including public and privately-owned restricted sites, as well as some remote and hard-to-reach areas. "Site visit Insights" provides a behind-the-scenes perspective of wildlife biology, featuring photographs and interesting discoveries and happenings SFWO biologists experience in the field.

Wildlife Biologists:
Josh Hull, chief, Recovery and Listing Division, Sacramento Fish and Wildlife Office
Jennifer Norris, field supervisor, Sacramento Fish and Wildlife Office

Site visit location: Wetlands in Yosemite National Park

What was the purpose of the site visit?
The purpose of the visit was to see California red-legged frog habitat in Yosemite National Park. In 2016, Yosemite National Park began releasing California red-legged frogs into habitat along the Merced River as part of an effort to return native species to the park. The frog is federally listed as threatened under the Endangered Species Act and is found in streams and wetlands throughout the Sierras and Bay Area. The California red-legged frog is named for its colorful legs and belly; it vanished from the park half a century ago. It is the type of frog featured in Mark Twain's short story "The Celebrated Jumping Frog of Calaveras County."

Where did you go?
Wetlands adjacent to the Merced River in Yosemite Valley in Yosemite National Park, California..

What partners were you working with and what is the nature of SFWO’s partnership with them?
On our site visit, we were accompanied by park biologists as they surveyed for the species in pools where tadpoles and juveniles were released last year. Yosemite National Park is one of our most valued partners for conservation. They manage pristine habitat and help us monitor and enhance populations of many listed species, including the red-legged frog. This project includes an important partnership with the San Francisco Zoo, where the frogs are bred and reared before release and a private landowner who has allowed collection of eggs and tadpoles from her property. The collaboration between all the parties is key to this project's success.

What did you learn from this site visit that you didn’t know before?
Yosemite biologists are using some new technology to monitor frogs. Chip detection technology allows them to detect frogs that may be present at these densely vegetated sites. We learned that the frogs may begin breeding earlier in the year at high elevation sites. Although there was snow on the ground, the warmer days allow for frogs to become active and begin moving to breeding areas.

What surprises did you encounter during the site visit?
We were surprised to see frogs using ponds that are snow covered in winter. While this isn't uncommon for Sierra Nevada populations, we hadn't encountered this before since ponds in the Bay Area never freeze.

Last updated: February 7, 2019