Critically Endangered Southern Mountain Yellow-Legged Frogs Raised at the Aquarium of the Pacific Released to the Wild

September 10, 2026

Long Beach, California-Approximately 653 critically endangered southern mountain yellow-legged frogs (Rana muscosa) were recently released into their native California mountain region habitat by staff from the Aquarium of the Pacific, Los Angeles Zoo, and U.S. Geological Survey (USGS). Of the 653 frogs that were released, 394 were headstarted at the Aquarium of the Pacific, marking the Aquarium's largest release of this species. The tadpoles were produced at the Los Angeles Zoo's southern mountain-yellow legged frog breeding program and transferred to the Aquarium of the Pacific, where animal care staff reared them through metamorphosis to froglets and frogs. This release brings the total number of this species that the Aquarium has helped rear and release to 1,032.

"We have been looking forward to releasing this cohort of frogs back into the wild," said Erin Lundy, the Aquarium's conservation initiatives manager. "The more frogs there are in their native habitat, the more of a chance we have to increase their survival."

Southern mountain yellow-legged frogs are native to the San Gabriel, San Bernardino, and San Jacinto mountains. They are a medium-sized amphibian, measuring between 1.5 and 3.25 inches on average. Adult frogs are a mix of brown and yellow coloring, but can also be gray, red, or greenish brown. They usually have dark spots or splotches that can look like lichen or moss and help the frog camouflage. The belly and underside of its back legs and sometimes front legs are yellow or light orange, which lends itself to the frog's common name, "yellow-legged."

In response to the 2020 Bobcat Fire, which burned most of the remaining habitat for the endangered southern mountain yellow-legged frog, the Aquarium of the Pacific joined efforts with local zoos and government agencies to rescue southern mountain yellow-legged frogs and aid in their recovery. Partners include the United States Geological Survey (USGS), U.S. Fish and Wildlife Service (USFWS), U.S. Forest Service (USFS), and the California Department of Fish and Wildlife (CDFW) who help monitor and oversee releases, and the Los Angeles Zoo, which successfully breeds the frogs to produce offspring for release into the wild.

The rescue program is designed to bolster populations in the wild in an effort to save this species from extinction. The Aquarium serves as a nursery to care for and raise tadpoles into frogs and froglets until they are ready for release, which typically takes one to two years. To help southern mountain yellow-legged frogs recover, the public can support this conservation effort by staying on marked trails and paths, respecting signs announcing off-limits areas when visiting local mountains, and reducing your carbon footprint.