State Income-Tax Forms Are for the Birds : Wildlife preservation: Donations via Line 50 help ensure the survival of such endangered species as the light-footed clapper rail.

For Southland residents still slogging through state income-tax forms 10 days before doomsday, Line 50 might be just a hazy blur in the race to the dotted line.

But for almost 300 species of wildlife, including an endangered bird found in the wetlands of Seal Beach, Line 50 represents a virtual lifeline out of the black hole of eventual extinction.

The item, which asks for tax-deductible contributions to California’s Rare and Endangered Species Preservation Program, funds projects aimed at keeping rare, threatened and endangered plants and animals alive and breeding.

On Thursday, state and federal officials went to the Seal Beach National Wildlife Refuge to talk about one of the program’s successes--the light-footed clapper rail, a shoreline bird that inhabits the receding marshes abutting the coast.

Despite declining numbers statewide, the clapper rail has been mounting a slow but steady comeback in Seal Beach since officials began building wooden nesting platforms five years ago for the tawny-chested birds.

“Last year, there were 16 pairs breeding” in the Seal Beach refuge, said Dick Zembal, a biologist for the U.S. Fish and Wildlife Service. “This year, in my latest count, there were 28.”

Zembal, a clapper rail expert, came up with the idea of nesting platforms back in 1986, when the population of clapper rails swooped perilously low. On Thursday, with the smell of brine in the air and a blazing sun beating down, Zembal and members of the California Conservation Corps erected another platform, adding to the more than 60 already dotting the marshland.

“Basically, if we don’t help one species, another species will die. It’s just a chain reaction,” said corps member Peter Beltran, 18, as he lugged the slatted platform out onto Nasa Island, a stretch of marsh grasses moated by seawater.

Beltran, whose T-shirt sported the statement “I’ve Been Working on the CLAPPER RAILroad,” added: “If we don’t do anything about it now, I don’t think we’ll do anything about it later. And then my children won’t be able to see the birds.”

On Thursday, he didn’t see any clapper rails either as he helped set up the platform. A secretive bird, it stays hidden, picking its way through the marsh vegetation.

The birds once inhabited coastal marshes from Santa Barbara to Baja California. But to accommodate the Southland’s burgeoning population, more than 90% of the wetlands have been drained, diked or buried beneath dredge spoils, according to the state Department of Fish and Game, which runs the endangered-species campaign.

At one point, only six pairs of clapper rails were believed to inhabit the Seal Beach marsh, a 911-acre expanse surrounded by the Seal Beach Naval Weapons Station. The numbers have recently increased, thanks in part to Zembal’s raft-like creation. The platforms, skewered by a wooden dowel, float in place when the twice-daily high tides sweep in from the ocean.

“They’ve taken to those rafts like crazy,” said Zembal, a former professional basketball player whose interests turned to wildlife conservation 12 years ago. “Last year, we had 50 nests, and 28 of those had eggs.”

The biggest headache now comes from trying to thwart red foxes, whose predatory habits account for much of the recent overall decline of clapper rails.

“The problem is the clapper rail is here year-round--it’s dependent on this (marsh) for its habitat,” Zembal said. “The fox is here year-round too, and the clapper rail’s a major meal.”

Trapping and removing the foxes has met with opposition from some animal-rights groups, so Zembal resorts to deception--a patch of tumbleweed placed on top of a platform to keep it hidden from sharp fox eyes.

Officials from the endangered-species campaign said the platforms will continue to be funded as long as necessary by Line 50 donations, which totaled nearly $1 million last year.

Robert Caughlan, the campaign’s spokesman, encouraged concerned taxpayers to contribute. “My major mission in life is to let people . . . know they can help when they fill out their tax forms,” he said. “You get a little tax break, and we get the money.”