Yellow-legged frog eggs reintroduced to habitat

Eggs from an endangered species of frog produced through a breeding program at the San Diego Zoo’s Institute for Conservation Research were released back into their native Southern California mountain habitat, it was announced Friday.

About 500 eggs from the mountain yellow-legged frog were reintroduced in a creek on the James San Jacinto Mountains Reserve near Idyllwild through the collaborative program with the U.S. Geological Survey, U.S. Forest Service and U.S. Fish and Wildlife Service, according to the zoo.

It is the first time scientists have tried to reintroduce eggs from the mountain yellow-legged frog back into their former habitat.

The eggs were released into deep permanent pools on the creek, where they will be closely monitored by biologists from the USGS.

It will take two years for the tadpoles to morph into adults, according to the zoo. Because they are not a migratory species, the frogs will stay in the creek within the bounds of the preserve, which is part of the University of California Natural Reserve System.

“This is a momentous day — the first reintroduction of these endangered frog eggs ever back onto their natural habitat and the San Diego Zoo is thrilled to be a part of it,” said Jeff Lemm, research coordinator for the zoo’s Institute for Conservation Research.

There is now only a small wild population of less than 200 mountain yellow-legged frogs in the San Gabriel, San Bernardino and San Jacinto Mountains, according to the zoo.

Once common throughout much of Southern California, the mountain yellow-legged frog has been decreasing in numbers since the 1970s due to decreasing habitat, pollution, invasive species, climate change and a deadly fungus.

In 2006, scientists collected mountain yellow-legged frog tadpoles from the remaining wild populations in the San Jacinto Mountains and took them to the zoo where, for the first time, researchers were able to establish a captive breeding program for the species.