U.S. Moves to Protect the Gnatcatcher : Environment: The proposal to put the bird on the endangered species list could profoundly affect development throughout much of the Southland.

In a decision that could have a profound effect on development throughout much of Southern California, the U.S. Fish and Wildlife Service on Thursday proposed adding the California gnatcatcher to the nation’s endangered species list.

The long-awaited announcement triggers a review process that may well culminate next year in federal protection of the tiny songbird, which has been the focus of a fierce debate between Southern California developers and environmentalists pushing to protect the bird.

The decision means that the environmentalists may have cleared their biggest hurdle, because the federal agency rarely decides against listing a species once it is proposed. Only new scientific data would prompt the agency to change its mind, and that has happened in only 1% or 2% of the cases, said Robert Ruesink, chief of listing at the agency’s Western regional office in Portland.

The federal decision comes only six days after the California Fish and Game Commission denied protection for the bird, concluding that the scientific data was unconvincing.

But the federal wildlife agency concluded that the gnatcatcher is in serious jeopardy of extinction, mostly because of “substantial loss and degradation of its habitat,” the vanishing scrub that lines the region’s coastal canyons.

“There was a high degree of certainty in this case,” said Jeff Opdycke, supervisor of the federal agency’s Southern California field office here in San Diego County. “The evidence we have compels us to propose this species for listing.”

The agency now must review any new scientific data and obtain public comments before making its final decision on listing. The bird is granted no protection during the review process, which, under federal law, can take up to one year.

Southern California’s developers and builders reacted Thursday with extreme disappointment and concern, saying that the decision creates so much uncertainty in an already ailing industry that projects could grind to a halt.

“It certainly will hurt the financing prospects,” said Frank Panarisi, president of the Construction Industry Federation in San Diego. “This will identify a further risk in development projects, so money will tighten up even more and it will delay the recovery of our economy.”

The building industry strongly disagrees with the federal agency’s assertions, saying that large amounts of land have been permanently preserved, much of it good habitat for the bird.

“The science is on our side. This animal is not even remotely threatened with extinction,” said Hugh Hewitt, an attorney representing the Building Industry Assn. of Southern California.

Jonathan Atwood, an ornithologist who filed the petition seeking listing after studying the bird for more than a decade, called Thursday’s announcement “an important milestone in a very long process that’s still to come.”

The gnatcatcher, a 4-inch insect-eating bird with blue-gray feathers, resides in Orange, San Diego and western Riverside counties, and a small part of the Palos Verdes Peninsula. Once common throughout the Southland, fewer than 2,000 pairs now exist, according to Atwood’s data.

During months of intense debate and lobbying, Southern California developers called the bird’s listing their “worst nightmare,” while environmentalists said it was their best hope for preserving much of the region’s natural terrain and sensitive wildlife.

The agency’s proposal was only a partial victory for environmentalists, since the federal agency denied emergency protection of the bird, which would have imposed immediate safeguards.

Still, that was more than the state was willing to grant.

This is not the first time that federal officials have acted when the state has refused. Thirty-five other species, including the Northern spotted owl, are on the federal list but not the state list.

Federal wildlife officials said that final listing would have broad implications for land use in Southern California, since many proposals to build roads, houses and public works projects in the Southland would affect the bird’s habitat.

The birds have been seen on or near land proposed for the San Joaquin and Foothill toll roads in Orange County and two proposed freeways in San Diego County. Housing developments by the Irvine Co. and the Otay Ranch, a large project by the Baldwin Co. in south-central San Diego County, also could be affected.

“Development and growth will proceed differently than they have in the past,” Opdycke said, adding that he believes the days of large, sprawling developments with sweeping effects on natural terrain are over.

A Bird of Controversy

The U.S. Fish and Wildlife Service has proposed adding the California gnatcatcher to the federal endangered species list, potentially delaying numerous development projects in Orange, Riverside and San Diego Counties. Last week, the tiny songbird was denied state endangered species protection

Size: 4.5 inches

Call: A kittenlike mew.

Habitat: Sagebrush mesas, dry coastal slopes.

Location: Southland to northern Baja California.