Endangered species under the microscope

It slithers through the ponds and marshes of San Mateo County.

The San Francisco garter snake hunts in the wetlands for the California red-legged frog -- a fellow endangered species.

Both creatures need each other to survive, but both are on the brink of extinction because of urbanization, excessive use of pesticides and the natural evolution of streams and ponds.

"The species have gotten limited areas to live in because of changes in climate and changes of habitat over time. And all humans have encroached upon it further," said Lennie Roberts, the county legislative advocate for the Committee for Green Foothills. "It's important to maintain that diversity of species."

Intense recovery plans are in place to bring their numbers back, such as creating artificial habitats, but there are no indications that the safeguards by the U.S. Fish and Wildlife Service are working.

Locally, the County Board of Supervisors recently adopted a resolution to support the Endangered Species Act. The act's goal is to protect habitat and come up with recovery plans to increase population.Meanwhile, developers and public agencies have been forced to alter construction projects and have changed how areas such as the San Bruno Creek are maintained on an annual basis.

In the next year, federal officials will do status reviews to provide a snapshot of what's happening to those species, said Jim Nickles, a spokesman for the Sacramento office.

The San Francisco garter snake was put on the federal endangered-species list in 1966, and the red-legged frog has been on the list since 1996.

It is the largest native frog in the western United States and ranges from 11/2 inches to about 5 inches in length. The abdomen and hind legs are red, and its back has small black flecks and background colors of brown, gray, olive or red. It spends its life in and near sheltered backwaters of ponds, marshes, springs, streams and reservoirs, and breeds from November through March.

Historically, the red-legged frog was considered a delicacy and was harvested commercially during the Gold Rush. Now, its enemy -- other than the San Francisco garter snake -- is the bullfrog.

In the snake's case, poachers have been known to catch it because of its beauty.

"The San Francisco garter snake is very imperiled, and we're just making progress on getting them back," said Al Donner, assistant field supervisor for the U.S. Fish & Wildlife Service.

The non-poisonous snake has a bright orange head with black and red stripes, with a wash of turquoise. It is typically 1 to 3 feet in length, and its locale is limited to a few wetlands near San Francisco International Airport, around Crystal Springs Reservoir and along the coast from Pacifica to Point Ao Nuevo.

At current count, there are about 1,500 of the snakes, but no count is available for the frogs. Both species have a long way to go before they can be taken off the endangered-species list.

In order for that to happen, an endangered species has to sustain itself in the wild, Roberts said.

"There's always debate on how robust a population needs to be," she said. "There's a lot of factors. It has to be able to reproduce in the wild and not suffer from the ups and down (of nature)."

Developers and public agencies that propose projects are required to go to the federal agency if there's a concern about the presence of an endangered species. A biologist is called and sets up parameters, Donner said.

In the case of the Devil's Slide tunnel project in Montara, a number of swampy zones known to have red-legged frogs are fenced off during construction.

With maintaining "Cupid Row" in San Bruno -- a canal built by the county to manage flooding from San Bruno Creek between the Caltrain tracks and Highway 101 -- county public works crews have had to remove silt manually, so as not to trample on the frogs' sensitive habitat.

Also, federal and state permits are required to maintain the area, home to the garter snakes and frogs. Clearing vegetation is a $90,000 project and lasts more than three months, said San Mateo County Public Works Director Neil Cullen.

Saving the snakes and frogs requires controlled burns on the San Mateo coast and the creation of critical habitat, a formal designation that an endangered species exists in that area. In 2004, the U.S. Fish & Wildlife Service created two wetlands to help frogs breed at Mori Point in Pacifica. Biologists immediately found red-legged egg masses in one of the new ponds.

People won't see a critical habitat for the San Francisco garter snake, said Sean Barry, a biosafety officer at the UC Davis, and a former biologist with the state Department of Fish and Game.

"They're going to keep their localities secret," he said. "People who collect snakes have never showed much interest in minding the laws."

Despite all the safeguards, only a handful of species have been de-listed.

Barry said he's reassured that a significant amount of habitat on the coast is being protected.

"The snakes will be around for a long time," Barry said. "They (snakes and frogs) are a part of the natural world."