The Los Angeles Zoo has released more than 650 endangered southern mountain yellow-legged frogs into the San Gabriel Mountains, continuing a multi-year effort to bolster the species' population and support local ecosystems. The amphibians were reintroduced into streams in their natural habitat on two separate days in August.
This initiative is part of the Southern Mountain Yellow-Legged Frog Recovery Program, a collaboration between the LA Zoo, the San Diego Zoo, the U.S. Geological Survey (USGS), and other wildlife agencies, which began in 2018. Since the program's inception, the LA Zoo has released nearly 7,000 frogs bred in captivity.
More than half of the frogs recently released were raised in the zoo's bio-secure amphibian headstarting facility. This specialized environment allows for close monitoring from breeding and hatching through to a robust juvenile stage. According to zoo officials, releasing the frogs at a more mature size increases their chances of survival by making them less susceptible to predators and environmental challenges.
"By raising these sensitive amphibians in a specialized, temperature-controlled environment, we are significantly increasing their chances of survival," said Byron Wusstig, Curator of Ectotherms at the LA Zoo, in a press release. "Returning 227 robust frogs to the San Gabriel Mountains is a direct result of this expanded capacity and the tireless dedication of our collaborative team."
The southern mountain yellow-legged frog, federally listed as endangered since 2002, is characterized by its medium size and a color pattern of brown and yellow that can also appear grey, red, or greenish-brown with dark spots. These frogs are typically found in streams within Southern California mountain ranges, including the San Gabriel, San Bernardino, and San Jacinto mountains.
Conservationists believe that boosting the frog population will have positive ripple effects, benefiting other species and contributing to the health of Southern California's watersheds. In the coming weeks, approximately 112 tadpoles bred at the LA Zoo are scheduled to be transferred to the Santa Ana Zoo for continued care.
The southern mountain yellow-legged frog can be viewed at the LA Zoo's Living Amphibian, Invertebrate, and Reptile exhibit.