By U.S. Forest Service
Contributed

A team of scientists from the San Diego Zoo Wildlife Alliance, University of California, Los Angeles, U.S. Forest Service, California Department of Fish and Wildlife, and the U.S. Fish and Wildlife Service reintroduced a group of 253 endangered Mountain Yellow-legged Frogs to a remote site on the San Bernardino National Forest July 8. This release is the second to occur at this location, after the California Department of Fish and Wildlife completed an extensive habitat improvement project to benefit the frogs. An additional release is planned at this site later this month, bringing the total number of juvenile frogs to be released this year close to 400.
The frogs were bred by the San Diego Zoo Wildlife Alliance and are 1 year old. It is hoped that after completing successful overwintering in their mountain habitat, these frogs, which are a mix of males and females, will survive for the next few years to reproduce and establish a self-sustaining population in this portion of their range.
For more than 20 years, the U.S. Fish and Wildlife Service, California Department of Fish and Wildlife, U.S Forest Service, U.S. Geological Survey, San Diego Zoo Wildlife Alliance and other partners have worked together on recovery actions for the Southern California population of Mountain Yellow-legged Frogs.
“It will take many partners working together to help us fully restore Mountain Yellow-legged Frogs throughout their Southern California range,” said Scott Sobiech, field supervisor for the U.S. Fish and Wildlife Service’s Carlsbad Office. “Although the frogs still face many threats, this release is a tremendous example of the progress we are making toward recovery for the frog.”
Getting the frogs to the release site involved transporting them by vehicle to a trailhead in special cooler backpacks that maintain a suitable temperature for this high-altitude species, and then making a more than 5-mile hike to the actual release location.
Historically, the Southern California population of Mountain Yellow-legged Frog was widely distributed across the San Gabriel, San Bernardino, San Jacinto and Palomar mountains. Several factors, including non-native predators, recreation impacts, and disease contributed to the disappearance of the species from most of its habitat by the time it was listed by the Service as an endangered species under the Endangered Species Act in 2002. At the time of listing, the Service estimated there were fewer than 100 adult frogs left in the wild.
Over the years, recovery efforts have included management of lands on Angeles and San Bernardino national forests to minimize human impacts to habitat; and conservation and research programs by the San Diego Zoo Alliance, U.S. Geological Survey, Los Angeles Zoo, Omaha’s Henry Doorly Zoo and Aquarium, Santa Ana Zoo, and UCLA to inform future conservation and management of the species.