Funworld JULY 2007
Conservation Closeup
Reestablishing the American Bird
by J.B. Elderkin
The San Francisco Zoo’s program has helped the bald eagle breed in captivity and reclaim its place in the wild

The San Francisco Zoo’s California Bald Eagle Breeding Program began in 1985 under dire circumstances. By the 1970s the bald eagle had nearly gone extinct—only 35 pairs remained—as the prolonged use of DDT, the first modern pesticide, prevented females from laying viable eggs. For Americans, this was no ordinary environmental concern. The bird is the official national symbol of the United States—bald eagles adorn currency, the national seal, and countless images that invoke a patriotic spirit. A national outcry erupted at this news, DDT was banned, and a number of conservation projects, including the San Francisco Zoo’s program, began working to save the birds.
The zoo’s program focuses on breeding and releasing eaglets into the wild, and it is now home to seven breeding pairs of bald eagles (the number has varied slightly over time). The birds came to the program from the Channel Islands off the coast of Los Angeles. Taken as 4- to 6-weekold eaglets, they were nurtured and paired together. Bald eagles mate for life, so keeping them together is an important part of the conservation effort.
The program began with desperate measures. The staff tried to incubate contaminated eggs that had been removed from the islands by covering them with artificial skin and even coating them in wax.
But beginning in 1991, eaglets born on site were released back onto the Channel Islands site. For a time, the success of the program remained uncertain because the long-term effects of the DDT have continued to affect the environment. But zoo officials found the released eagles survived well on the northern end of the islands, and recently two of the zoo’s birds successfully hatched an eaglet—the first natural hatching on the islands in 50 years.
There are now 103 bald eagles living in the wild, and some of them have left the Channel Islands and are colonizing other areas of California. San Francisco Zoo Director of Conservation John Aiken says this is a particularly important development. “The bald eagle means a lot to Californians. They are our flagship species and they’ve provided hope for how we can deal with future conservation issues,” he says. The program has been such a success that this will be the final year the zoo releases bald eagles back onto the Channel Islands. Other birds, such as golden eagles, will become the zoo’s focus, with the hope that other species will follow the bald eagle’s path to recovery.




