RESCUED MOUNTAIN FROGS NOW THRIVING IN L.A. ZOO.

Byline: Emily Sachs Staff Writer

LOS ANGELES - The most endangered animal in the San Bernardino National Forest no longer lives there. It's sitting in a zoo.

And if experts' hunches are right, the small frog that was once a nuisance in the foothills won't be going home anytime soon. Its home may no longer be there.

Eleven Rana muscosa, or mountain yellow-legged frogs, rescued after last fall's destructive Old Fire await word from researchers whether any of their creekside habitat in City Creek, just above San Bernardino, was spared in the subsequent flooding and mudslides.

The researchers will also look for other frog survivors, although the likelihood is slim that either search will succeed.

Naturalists suspect that the creek and creekside pools where they breed have disappeared beneath the staggering quantities of sediment that swept down the mountainside, taking with it the habitat of the 11 survivors and their kin, which typically live within three hops of the creek.

``If we had a larger population of frogs to begin with, maybe an event like this wouldn't be as catastrophic,'' said Kathie Meyer, a wildlife biologist with the San Bernardino National Forest.

When federal officials first listed the frogs as endangered in July 2002, it was estimated that only about 100 adult frogs remained in Southern California in seven locations, including five streams in the San Gabriel Mountains and one stream in the San Jacinto Mountains.

Officials suspect the total was already smaller by September when the Bridge Fire burned some vegetation near City Creek, raising worries about the viability of the frog to survive if nearby vegetation was gone. By the time the Old Fire raged in late October, officials knew they had to find some frogs before they were lost forever.

With disposable Ziploc containers in hand, a pair of scientists hiked to remote areas of City Creek in November.

They were lucky to find 11 young frogs, which were on the verge of their winter hibernation, said Adam Backlin, an ecologist with the U.S. Geological Survey San Diego Field Station.

The frogs were taken to the Los Angeles Zoo, where they have grown and flourished, said Russ Smith, the zoo's curator of reptiles.

Inside a private outbuilding near the World of Birds Show area, the yellow-legged frogs live in four medium-sized aquariums under lamps that simulate sunlight.

Smith said they eat every other day, being fed a variety of crickets and other insects that they would find in the wild. When they are big enough, Smith said pinky (baby) mice will be added to the menu.

About the size of an man's palm and with the coloration of moss and rocks, they can blend into their surroundings. Their name derives from their yellow-colored legs. The whole underside is yellow, although the rescued frogs' hues are more muted than bright.

A shady water hyacinth, smooth rocks and terra-cotta flowerpots in the frog room give them places to hide. Smith also demonstrated how the frogs crouch in defensive position when they sense danger.

Ironically, the biggest risk for the frogs is something they can't guard against: a mysterious chytrid (aquatic) fungus that has taken out many captive frog populations, including some zoos.

It is unknown how the deadly disease is spread. It is suspected that humans are at the root, so care is taken to limit exposure to the frogs at the zoo and take care in what they touch.

``We were pretty confident that the mudslides were going to be a huge impact on the frog, whereas bringing them into captivity, there are problems, but not as many problems as leaving them in the wild, at least in this site,'' Backlin said.

Backlin said the forest service would like to use the frogs as breeding stock to eventually replenish the San Bernardino frogs, assuming they have disappeared.

The plan requires having a new home where the species' first-ever captive breeding can take place.

It would also delay by two to three years their reintroduction to their original forest home. But it also gives scientists the chance to make long- overdue leaps in learning about the species.