653 Endangered Yellow-Legged Frogs Raised at the L.A. Zoo Are Now Hopping Free in the San Gabriel Mountains

In a significant conservation initiative, the Los Angeles Zoo has successfully released 653 endangered southern mountain yellow-legged frogs into their native habitat within the San Gabriel Mountains. Taking place over two days in August, this latest release brings the total of L.A. Zoo-bred frogs returned to the wild to nearly 7,000 since the commencement of the recovery programme.

The first batch of 338 frogs was released on August 19, followed by a second group of 315 on August 27. This milestone event involved collaboration with staff from the Aquarium of the Pacific and the U.S. Geological Survey (USGS), with all the frogs being bred at the zoo’s facilities.

A key aspect of this release is the introduction of frogs reared in the zoo’s newly established bio-secure amphibian headstarting facility. This innovative centre, situated in a reworked section of the zoo’s former Children’s Discovery Center, is equipped with advanced tanks and life support systems that ensure optimal water quality for the frogs. The on-site care team closely monitors the amphibians from the moment they hatch, providing a controlled environment that supports healthy growth.

By nurturing the tadpoles until they metamorphose into larger, more robust frogs, the team enhances their chances of survival once they are reintroduced into the wild. The intention is to release these animals at a more advanced stage, thereby reducing their vulnerability to predators and environmental struggles they might face in their natural setting.

Byron Wusstig, the L.A. Zoo’s curator of ectotherms, expressed the significance of this development, stating, “Seeing our new headstarting facility transition from a concept to a fully operational reality is a monumental milestone for the recovery of the southern mountain yellow-legged frog.” He emphasized that the specialised, temperature-controlled environment dramatically increases the survival odds for this delicate species.

The southern mountain yellow-legged frog, classified as endangered by the International Union for Conservation of Nature, has a limited presence in the wild. These medium-sized amphibians, typically measuring between 1.5 to 3.25 inches, inhabit perennial streams in specific regions of the San Gabriel, San Bernardino, and San Jacinto Mountains. Adults display a colour palette that ranges from brown and yellow to grey and greenish-brown, often featuring dark spots that aid in their camouflage.

The recent releases mark a significant contribution to the Southern Mountain Yellow-Legged Frog Recovery Programme, which is administered by the USGS and supported by a diverse coalition of partners. This network includes the San Diego Zoo Wildlife Alliance, Omaha’s Henry Doorly Zoo and Aquarium, as well as various government agencies such as the U.S. Forest Service and the California Department of Fish and Wildlife.

In addition, other institutions such as the Aquarium of the Pacific, Santa Ana Zoo, Big Bear Alpine Zoo, and Birch Aquarium have joined the ongoing conservation efforts. Among the planned activities, approximately 112 tadpoles bred at the L.A. Zoo are scheduled for transfer to the Santa Ana Zoo for continuous care later this September.

For those interested in learning more about this species, the southern mountain yellow-legged frog can be viewed at the L.A. Zoo’s Living Amphibian, Invertebrate, and Reptile exhibit, also known as LAIR. This exhibit provides the public with an opportunity to appreciate these endangered frogs and understand the conservation efforts being made to ensure their survival in the wild.

As efforts to rehabilitate and conserve this vulnerable species continue, the work being done by the L.A. Zoo and its partners serves as a vital reminder of the importance of wildlife conservation in preserving our planet’s biodiversity. The successful breeding and release of these frogs demonstrate that with collaborative effort and innovative approaches, there is hope for the future of endangered species.