Local frog makes 'threatened' list
Publication Date: Friday May 24, 1996

ENVIRONMENT: Local frog makes 'threatened' list

Red-legged amphibian of Calaveras fame is first in line after lifting of moratorium

by Heather Rock Woods

The U.S. Fish and Wildlife Service on Thursday officially listed the California red-legged frog, whose few habitats include San Francisquito and Matadero creeks in Palo Alto, as a threatened species. The amphibian, colored red on the underside of its legs and belly, was the first species to be added to the federal endangered species list since a 13-month Congressional moratorium on listing new creatures was lifted last month.

"It's a really good indicator of the health of our aquatic environment," said Diane Windham, listings coordinator for the Wildlife Service in Sacramento. "The frog's habitat has been severely degraded and fragmented. Another critical factor is bullfrogs, non-native species that were introduced, which prey heavily on red-legged frogs and compete for habitat and food," she said.

The threatened status means the species is likely to become endangered--another status which means the species is likely to become extinct. People cannot harm, harass, or kill the listed species or destroy its habitat. California had already treated the frog as a "Species of Special Concern," but the federal designation protects the animal's habitat as well.

The biggest frog native to California, the red-legged variety has disappeared from 70 percent of its range, including the Sierra, the Central Valley and southern California. The species still remains in pockets in 240 stream drainages in the coastal mountains of central California.

The "celebrated jumping frog of Calaveras County" in Mark Twain's 1865 story is believed to be a red-legged frog because the species was very common then.

Healthy populations of more than 350 adults remain only in Pescadero Marsh on the San Mateo County coast, the Point Reyes area and the Monterey region. At least one frog has been seen in 44 locations in Santa Clara and San Mateo counties.

The bullfrogs were introduced to California in the late 1800s as a source of frog legs when the overharvested red-legged frogs became harder to find.

"They're only in isolated places in the Santa Clara Valley. The populations have been greatly reduced from what they were over the last century," said wildlife biologist Rich Seymour, who studies the frogs in conjunction with the Coyote Creek Riparian Station in San Jose.

Seymour confirmed that he has seen at least one red-legged frog in Palo Alto's San Francisquito and Matadero creeks, but didn't want to reveal population locations.

"If I saw 20 red-legged frogs in a long night's work it would be a good find. Much more often I see one or two," Seymour said.

He said the frogs still live in local creeks partly because Stanford University owns so much undeveloped land along the creeks. "I've started to notice that you find them in areas where it hasn't been developed right up to the creek, where there's quite a large buffer of undeveloped land," Seymour said.

Stanford will have to do a biological survey as part of the environmental impact report on a proposal to build 1,100 housing units on Sand Hill Road along San Francisquito Creek. If the frog is present, Stanford would have to study the project's impact on the animal and ways to mitigate it. But university spokesman Andy Coe said the frog hasn't been spotted in that portion of the creek.

To conserve the frog's habitat, the Wildlife Service will encourage keeping creeks as natural as possible. A local group headed by the Peninsula Conservation Center has already been working on a plan to improve flood control while enhancing the natural state of San Francisquito Creek.



Back up to the Table of Contents Page