Helping Bald Eagle Raise Heir Naturally : Biology: Pollution and hunting wiped out the birds in the Channel Islands. But this year, for the first time, an egg laid on Catalina Island was successfully hatched.

The endangered bald eagle, which disappeared from the Channel Islands decades ago because of illegal hunting and pesticide pollution, is showing the first signs of making a comeback on Catalina--thanks to the help of wildlife biologists.

In a long-awaited first for a pioneering eagle recovery project on the island, a young eagle laid a healthy egg on Catalina in March. The egg was taken from the nest and hatched in a distant laboratory incubator, producing a healthy chick that by November was back home flying in the wild.

It was an important moment for wildlife biologists, who for a dozen years have tried to re-establish the giant, white-headed predators on the island by importing eagles from other areas only to see them fail to reproduce. One of the problems is that high levels of the pesticide DDT had accumulated in the birds’ bodies, destroying the female’s ability to lay viable eggs.

But the arrival of a healthy egg gave them hope, and as it was being incubated at a Santa Cruz center established to save these endangered birds, the female was given a second, healthy egg to hatch and raise, one that had been imported from Northern California. This foster chick is also flying, proving that at least one nesting eagle could hatch and raise her young on Catalina Island. Eventually, the goal is to have the birds reproduce and raise chicks without human assistance.

When word of the double success flashed across the federal and state wildlife recovery networks, the message was hopeful: If she can do it again, it could be a sign that DDT’s deadly grip on the eagles may be broken.

“Getting a viable egg is significant. It suggests that conditions are improving out there,” said eagle expert Philip Schempf, chief of the U.S. Fish and Wildlife Service’s predatory bird management program in Alaska. “And it’s a good sign when a pair of eagles can raise a young bird there.”

The female that produced the good egg is named “Wray” and is from British Columbia. Captured as a fledgling specifically for resettlement in 1986, she was raised on Catalina and set free as one of three dozen birds introduced to the island by the Institute for Wilderness Studies. Only 14 remain on the island; the others flew away or died.

The five nesting pairs on Catalina produced eight eggs this spring. Each was taken to the University of California’s Predatory Bird Research Group laboratories in Santa Cruz for incubation. Only one hatched.

“One good egg is a very good sign, but we have to be cautious here, wait and see what happens next,” said Dave Garcelon, 37, founder of the Institute for Wilderness Studies and director of the Catalina recovery project.

The nonprofit institute, based in the Northern California city of Arcata, is funded by donations, grants and government contracts. To date, it has spent $400,000 trying to re-establish eagles on the island.

Wray actually laid two eggs this spring, but only one hatched. Experts say this is not uncommon even among healthy birds. When a bird’s real eggs are taken, they are usually replaced with plastic decoys, but Garcelon decided to put a viable Northern California egg in Wray’s nest.

“It was the first time we’d put a real egg back in a nest, but we wanted to see if she could hatch and raise a chick,” he said.

Ten days after Wray’s own chick hatched in the university incubator, it was put in a nest with foster parenting eagles in the San Francisco Zoo. Seven weeks later, the eaglet was brought back to the island for introduction into the Catalina ecosystem.

Such eaglets are raised in special cages built on high platforms in the remote, rugged island outback. They are never allowed to see their captors, even at feeding time. When they are ready to fly, the cage doors open and the birds are free to take off on their own.

“It is important not to let them see humans and connect us with their food supply,” Garcelon said.

Through the spring and summer, Garcelon and his crew took care of Wray’s natural chick and two imported eaglets on the platforms, while Wray took care of her foster chick in the wild nest. By fall, all four fledged (grew feathers) and took off on their own, testing their wings.

The adolescent eagles will remain in the area for several weeks, returning to the nest--or the platform--when they are hungry. But when they begin to hunt on their own, they may head for parts unknown. It is not unusual for them to stay away for a year or so, then return when they are ready to pair up and mate, he said.

“Wray’s chick stayed around for a while,” Garcelon said. “We saw it in November, then it was gone.” In fact, all four youngsters took off about that time. Wray’s foster eaglet returned and is establishing itself on the island.

The other three did not return, and at least one has died--run over and killed by a car as it scavenged meat on a remote Nevada highway. Officials learned of the death because the bird had been tagged with an identification band.

Even before Wray laid the healthy egg, the Catalina eagle recovery project was getting high marks from the experts. Started in 1980 by Garcelon, the program has pioneered recovery techniques that have been adopted in other areas.

“They’ve been a great stimulus to the bald eagle recovery programs all over the country,” said Brian Walton, coordinator of the University of California’s predatory bird research programs. Bald eagles are different from the larger, less colorful and more numerous golden eagles that prey on larger, inland mammals and are not considered endangered. Walton explained that bald eagles are from a separate species called “sea eagles” because their natural habitat is close to water.

They prey on smaller birds, often killing them in midair. Although eagles fish on their own, they often attack gulls or pelicans that have caught fish, forcing the smaller birds to give up their catch or die.

The eagles build huge stick nests in the cliffs or in the tops of gnarled trees high on the bluffs overlooking the ocean. Each breeding season, roughly February through March, Garcelon and his staff spend weeks in the wild, watching the nests. This season they are installing remote video cameras to keep a closer eye on the birds.

Like peregrine falcons and California brown pelicans, bald eagles were nearly wiped out in the 1940s and 1950s by the deadly effects of DDT. Even now, 20 years after DDT production was banned, pesticide residues show up in the fish and birds that are the eagles’ primary diet.

Minute traces of DDT in female eagles are enough to deplete their calcium production and weaken the eggshells. Most of the eggs are crushed in the nest, and those that aren’t broken seldom hatch.

The population of bald eagles in California had dropped to 20 nesting pairs by the time the birds were listed as an endangered species a quarter of a century ago. Since then, the number has increased to 100 pairs, most in Northern California, away from the worst DDT pollution.

Because of the heavy DDT pollution in waters off the Palos Verdes Peninsula, the idea of re-establishing eagles in the coastal islands had been dismissed until Garcelon revived it. The last nesting eagles had been seen on Catalina in the late 1940s. Unable to reproduce, they finally disappeared, Garcelon said.

When he started the project, Garcelon had a difficult time convincing skeptical government officials that they should give him permits to capture young Canadian eagles and introduce them to Catalina. They thought the effort would fail.

Then Wray laid her egg.

What’s in store for her now? She is expected to mate again this spring but will not be allowed to hatch her own eggs, which will be taken to Santa Cruz for incubation.

“We want to give her another year to see if there is any DDT buildup in her system before we let her incubate her own eggs,” he said.

If all goes as hoped, Wray will raise her own chick by 1993 and Catalina eagles will finally be on the way to recovery.

The Endangered Bald Eagle

+ Bald eagles, threatened with extinction by hunting and pesticide poisoning, were protected by Congress in 1940, then placed on the endangered species list in 1968.

+ A different species from the golden eagle, bald eagles are of a class called “sea eagles” because their prey comes from the water. They have white heads and white tails, weigh about eight pounds and have a wingspan of up to seven feet. The breeding season is February through March. They normally lay two or three eggs, and hatch one or two chicks.

+ According to a 1990 census by the U.S. Fish and Wildlife Service, there are about 40,000 bald eagles in the United States, most of them in Alaska (35,000) where they are thriving. There are an estimated 5,000 in the lower 48 states, mostly in the Pacific Northwest. Washington has 798, Oregon 350 and California 186.

+ In California, the population had been as low as 40 but that number has climbed back to unofficial estimates of 200. Most are in the Shasta-Trinity and Pitt River areas of Northern California. In other areas of the state, the numbers are low and the bird is struggling for survival, especially in Southern California.

+ The count on Catalina Island is 14 birds--five nesting pairs plus four youngsters. The other Channel Islands have no eagles, and most of Southern California is considered barren and too toxic for the birds. From Santa Barbara north to Monterey, there are only 22.