Hundreds of California red-legged frogs are packing their little frog suitcases to move to “parts unknown.” Well, not exactly.

The California red-legged frog (Rana draytonii) is a rare species of frog found almost exclusively in our state. It was once commonly found throughout much of California, but in 1996 the U.S. Fish and Wildlife Service designated it as “threatened” under the Endangered Species Act due to the disappearance of the species from about 70 percent of its range.

The adult California red-legged frog is 2 to 5 inches long and is the largest native frog in the Western United States. It has a reddish coloring on the underside of its legs and belly, hence its name. It became famous when Mark Twain featured it in his short story, “The Celebrated Jumping Frog of Calaveras County.”

Although the species is still fairly common along the California coast, the populations have declined significantly in Southern California. There are currently only three small populations in Los Angeles County. These populations are extremely small and isolated, causing great concern about the long-term persistence of the existing population.

Researchers with the National Park Service and U.S. Geological Survey have determined there are only about 100 adult frogs in a small section of Upper Las Virgenes Canyon Open Space Preserve (in the Simi Hills). Although the frogs seem to be thriving, they are limited to only a few hundred yards of stream and could easily be wiped out in a severe drought or other catastrophic event such as disease.

The primary threats to the frog have been invasive species and habitat loss. Non-native bullfrogs, crayfish and fish have been preying on California red-legged frogs and their eggs and tadpoles. Homes, farms and other buildings have been built on their wetland habitats.

Under the guidance of the U.S. Fish and Wildlife Service’s Recovery Plan, federal biologists have begun the process of attempting to return the threatened species to some of the Southern California wetlands where they once were abundant.

California red-legged frog eggs.

The project team, comprised of California State Parks, the National Park Service, Santa Monica Bay Restoration Commission, U.S. Fish and Wildlife Service and U.S.G.S. Western Ecological Research Center, have combined efforts to attempt to accomplish this task. They have begun transporting hundreds of eggs from the Upper Las Virgenes Canyon Open Space Preserve to stream habitats in the Santa Monica Mountains within national park boundaries, where it is hoped that they will thrive and repopulate.

These habitats, in Ramirez and Solstice Canyons, were chosen due to a lack of non-native predators. If this translocation effort works, the biologists plan to relocate the frog eggs to additional sites in Southern California in the future.

Federal biologists have asked the public to keep their distance if they see any mesh containers suspended above the water in these areas, so as not to disrupt the fragile re-introduction effort.

Hopefully, these efforts will enable the famous California red-legged frog to make a comeback in Southern California.

Linda Castro is a former attorney who is a nature enthusiast and animal lover.  She currently serves on the board of the SCV-based Community Hiking Club.  Her articles highlight local and community stories that are heartwarming, uplifting or inspirational.  If you have a story you’d like to share with her, contact her at poisonoak.linda@gmail.com.  Include photos if you’ve got them.