Bald eagles once lorded over the Channel Islands. No more. San Clemente Island loggerhead shrike, a bird, were common. No more. Dwarf foxes were once the largest terrestrial vertebrates. No longer.

Outsiders now tramp parts of the place -- black rats, feral cats, feral pigs, mule deer, golden eagles, ugly-as-sin buffalo.

Government and conservation groups are stepping up their campaign to return balance to this pocket of Southern California wilderness.

On Catalina, conservationists are babying bald eagle eggs to nurse the species to health. Wildlife workers hang from helicopters, plucking eggs from mountaintop nests.

On Anacapa Island, the National Park Service dropped poison this month to wipe out non-native rats that are eating native birds.

On San Clemente Island, about 60 miles off the San Diego coast, shrike are staging a comeback, thanks to the Navy, the San Diego Zoo and other groups.

On Catalina, San Miguel and Santa Rosa islands, foxes are being raised in captivity to stave off extinction. The fox population has dropped 92 percent since 1994.

On Catalina again, a tourist hot spot in warmer months, a conservation group sends hunters after feral pigs, while nearly all goats have been evicted.

"The primary goal is to restore the island, to allow people to enjoy California the way it used to be," said John Floberg, field biologist with the nonprofit Santa Catalina Island Conservancy.

The ecological restoration projects cost about $4.7 million last year. Channel Island biologists expect the costs to grow in coming years as many try to meet a government mandate for restoration.

"It's definitely worth it," said Tim Coonan, a National Park Service biologist. "We have to attempt to drive these islands back to a more natural state."

The eight islands have spawned scores of unique species and subspecies, including the dwarf fox, plants, the shrike and the island night lizard. Some are listed as threatened or endangered under the federal Endangered Species Act.

Coonan said the islands have relatively simple ecosystems, making them more vulnerable to calamity when alien species charge in.

"You end up with impacts that are very disproportionate to what you would find on the mainland," he said.

Canine distemper, probably introduced by an unleashed dog, killed more than 1,000 Catalina foxes in 1998. On the island's east side, 95 percent of the foxes were wiped out.

On three northern islands, part of Channel Islands National Park, golden eagles continue to kill foxes. On San Miguel Island, one fox remains in the wild.

The rest live in pens as part of a captive-breeding program started by the park service in 1999. The agency also is removing the golden eagles.

The 50-plus foxes are fed and monitored by technicians bunked on the sparsely populated islands. Most islands have a subspecies of the red, white and gray foxes, each smaller and more docile than their distant cousins on the mainland.

Captive foxes on San Miguel have produced only seven pups in two years, worrying biologists.

"It's nerve-racking," Coonan said.

That is one reason he and others are keeping close watch this winter on Catalina. On Pensioner's Pasture. On six young foxes tasting freedom for the first time, while the humans tracking them white-knuckle it.

Biologists Barker and John Sewell stand statue-silent on the pasture, using hand-held antennae and radio receivers to pinpoint the freed foxes. Each animal has a radio collar and a geeky name.

A blip or a blurp on the radio means pay dirt.

Blip. "There's V3B."

Blurp. "There's Q4G."

Said Barker: "That tells us they're still alive."

Big sigh of relief.

"And it's another day."

The men are with the Institute for Wildlife Studies, a Northern California conservation group conducting much of the field work on Catalina and other islands.

Wildlife experts say the Channel Islands restoration is unlike any other project in their profession.

On the mainland, a growing number of animals are managed, eradicated or reintroduced in the name of natural balance. Success is hard to measure because the ecosystem is more complex and porous.

The islands, because of their isolation, offer a stage for a broader makeover that could stick.

Take San Clemente Island.

For decades, goats and pigs ran roughshod over the island, destroying vegetation, until the Navy began removing or killing them in the 1970s.

Both are gone now. The native shrike is making a slow but steady comeback because of a captive-breeding program run with the help of the San Diego Zoo.

About 60 of the birds live in the wild; another 60 are in captivity.

At the moment, the biggest natural laboratory is Catalina.

The Santa Catalina Island Conservancy, which owns 88 percent of the island, is accelerating its work dramatically. The island's restoration budget has tripled in recent years.

With the help of the Institute for Wildlife Studies, the conservancy placed 21 foxes last winter in a captive-breeding program.

So far, so good. The animals released last month were born in the program.

"I think Catalina is really coming back well," said institute director David Garcelon.

Biologists also have relocated wild foxes to spread out the population and vaccinated them against canine distemper.

They also continue to nurse along the bald eagle population. There are four breeding pairs on the island.

The eagles produce eggs, but the shells are weak because of DDT. The man-made chemical was banned decades ago, but it remains in the ocean food chain off Los Angeles.

Dangling from helicopters, conservationists pluck the eggs from nests and coddle them in captivity to ensure successful births.

The Catalina bison are expected to catch a break. About two dozen of the woolly mammals were shipped over in the 1920s as props for a Hollywood western.

Now there about 350 of them.

The conservancy is studying the bison, but few expect them to get the boot. They are not as invasive as other animals, and they draw sightseers.

Feral pigs are another story. Armed with shotguns and dogs, wildlife specialists hired by the conservancy aim to weed out the animals by 2004.

But as death comes, so comes life.

So comes Q4G.

The female fox was born in captivity April 12. She weighed 2.4 pounds.

She lives on Pensioner's Pasture now, free to reclaim Catalina. Food is plentiful. Shelter is little problem. Conditions sound bucolic, so what's the worry?

The worry is that a lot could go wrong. The worry is that the released foxes will not survive the wild.

But Q4G presses on. She has her winter coat. She weighs about 6 pounds now.

Sometimes she ventures beyond the pasture.

Biologists take it as a great sign. This, they say, is how revivals begin, with baby steps.

Barker jiggers with his radio, and then hears her. Q4G coming in loud and clear.

Blurp, blurp, blurp.

"So far, things are going better than anyone could have hoped for."