Rare Bald Eagle on the Rebound in California

The bald eagle is soaring back from near extinction in California, but wildlife experts caution that the resurgence of the raptor on the West Coast may not last.

The majestic bird was placed on California’s endangered species list in 1970, clearing the way for state action to help the once-plentiful eagle survive in a difficult 20th-Century environment. At that time, there were only an estimated 25 breeding pairs in California.

Now, a wildlife expert reports that the number of eagles in the state has not only stabilized during the last decade, but has increased.

Ron Jurek, a wildlife biologist for the state Department of Fish and Game, said the latest estimate shows that there are 67 nesting pairs of bald eagles in 10 Northern California counties.

However, he added, it is too early to know if the increase will be permanent.

‘All Signs Are Consistent’

“All signs are consistent with a stable or increasing population,” Jurek said. “There is nothing to indicate that too few young are being produced each year to increase the population.”

Jurek said the same “signs of recovery” have been seen throughout the nation.

But he said the possibility that the eagle population will reach a point where the bird can be removed from the endangered species category is “many years away.”

He said “short-term improvements followed by declines” can occur in endangered species populations.

The bald eagle, with a six- to eight-foot wing span, disappeared rapidly across America during the middle of this century. Not surprisingly, the major reason for its decline was the encroachment of people.

The increasing human population resulted in a loss of nesting areas and food for eagles. People scared eagles away from favorite waterways where the birds fed on fish and from nests where abandoned chicks starved.

Another major problem was the use of pesticides, especially DDT, which reduced reproduction rates by causing thin eggshells and a high incidence of embryo deaths.

Jurek said the U.S. ban on DDT in 1972 was a “tremendous help” in stabilizing the eagle population. But he said residual DDT still in the environment continues to pose a problem, as does the current use of the pesticide in many other countries.

“Eagles can’t be left alone and be expected do to well,” Jurek said, stressing the importance of cooperative government-private programs to preserve the bird.

Under such programs, nesting and feeding areas are established and protected from human interference. Logging companies have cooperated by agreeing not to cut trees near nests. Also, fines and jail terms have been increased for people who shoot eagles.

California’s management program includes an effort to restore bald eagles to areas where they once thrived. Santa Catalina Island is one such case.

In 1980 and 1981, the Institute of Wildlife Studies, in cooperation with the Santa Catalina Island Conservancy, relocated 12 chicks to artificial nests on the island. Eleven of the eaglets came from Washington, one from Northern California.

Eight more birds have since been brought to Catalina, which had been bare of eagle nests for 40 years.

Jurek said the oldest birds--it takes five years for them to become adults--are expected to produce an egg this year. Because of the high mortality rate of eagles, only about half the birds brought to the island are expected to survive.

The Pit River area in Northern California’s Shasta County is one of the densest areas in the country for bald eagles, Jurek said. Eight pairs of bald eagles make their homes near Pacific Gas & Electric powerhouses in the area.

Ambitious Research Project

The birds’ presence has prompted the utility to sponsor one of the most ambitious eagle research projects.

As part of the two-year study, biologists climb to nests and place tiny radio transmitters on young eagles. The transmitters are designed to fall off after a month.

The effort is aimed at finding out more about the habits of eagles so that better programs can be developed to protect them.

To further upgrade protection efforts, the federal Fish and Wildlife Service has set up a Pacific States Bald Eagle Recovery Team, of which California is a participant.

Jurek said the team is developing a plan to coordinate the eagle-protection efforts of government agencies and private groups. The plan is expected to be completed next year.