Saving the California Condor

The California Condor (Gymnogyps californicus), a member of the vulture family, is the largest bird in North America and one of the largest in the world, with a wingspan of nearly ten feet. Condors once ranged across the continent, feasting on the remains of dead mammoths and mastodons. Today these relics of the Ice Age are some of the rarest birds on earth, saved from extinction by a massive conservation effort.

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California Condor, at the Phoenix Zoo

During the Ice Age, the California Condor roamed the skies from Alaska to Mexico and from Atlantic to Pacific, accompanied by an even larger relative called Teratornis. During this time, the North American plains resembled modern-day Africa, with elephants, camels, rhinos, and antelope. Together, the Condor and the Teratorn filled the role of aerial scavenger, feeding on the remains of kills left by American lions, cheetahs, and sabertooth cats.

About 10,000 years ago, as the Ice Age came to an end, the American climate changed, humans entered the continent, and the “megafauna” went extinct. The Teratorns became victims too, and died out. Their smaller Condor relatives, however, were able to hang on, feeding on dead bison and elk as well as beached whales and marine seals, though they will also scavenge small animals like rabbits. Native Americans referred to the Condor as the “Thunderbird”, believing that the flapping of its immense wings caused the sound of thunder.

By the time the Spanish conquistadores reached North America, the Condor’s natural range had shrunk to the area west of the Rockies, where it nested on cliff faces and large trees and made its living by eating carrion from dead animals. Like all vultures, the Condor has a naked featherless head and neck to allow it to poke inside the body cavities of dead carcasses. Although awkward and ungainly on the ground, the Condor is a superb flyer, able to ride thermal currents and glide effortlessly for hours at a time, looking for carrion.

The Condor population had already begun to decline further by the 1920’s, to a strip along the Pacific coast and into the southwestern United States. Many of the birds were shot by ranchers in the mistaken belief that they attacked sheep or young cattle; others were unintentionally killed by poison bait left out for coyotes and by lead shotgun pellets in unrecovered hunted animals. The birds were also crippled by the near-extermination by hunters and settlers of the large North American mammals that provided much of the birds’ food. The last Condor seen in the Grand Canyon area was in 1924. By 1940 there were no Condors outside of California.

In the 1960’s, the birds were further devestated by the effects of the insecticide DDT, which was sprayed on fields and ingested by herbivorous mammals where it concentrated in their tissues; when the Condors ate their flesh, the DDT caused them to produce abnormally thin eggshells which then broke, crippling reproduction. The insecticide was soon banned, but the Condors continued to decline. In 1967 they were placed on the Federal endangered species list. By 1975 they were nearly extinct.

In 1982, there were less than two dozen Condors left alive, and the US Fish and Wildlife Service concluded that the only way to save the species from extinction was to undertake a program of captive-breeding to increase its population. A number of Condors were captured and divided into two groups, which were placed at the Los Angeles Zoo and the San Diego Zoo for captive breeding. By 1987, there were only 9 birds left in the wild, and the US government decided to capture them all, removing the species completely from the wild and adding all of the remaining birds to the captive breeding program. There were exactly 27 California Condors left in the world.

This step provoked tremendous controversy. The environmentalist movement in the US was large, powerful–and divided. Most environmental groups supported the Federal captive-breeding effort, concluding that it was the only viable way to save the species. But a large faction opposed it, arguing that the species was likely doomed anyway, and that it was preferable to let it “die with dignity” and perish naturally in the wild rather than be subjected to captivity.

In the wild, Condors reproduce very slowly. Adults do not reach breeding age until at least six or eight years old, and the pairs, which mate for life, only produce one chick at a time. Each chick may stay with its parents for two years. A workable method was developed, however, to captive-breed the birds at much higher rates. Researchers found that if they removed the egg shortly after it was laid, the female would respond by laying another egg, known as “double-clutching”. Researchers were able to coax some birds into laying as many as four eggs per year. These were artificially incubated and the chicks were then hand-raised. To prevent the hatchlings from becoming imprinted on people, they were never allowed to see a human, but were cared for using anatomically exact hand puppets that resembled Condor parents.

By 1990, the breeding program had been spread to a number of other zoos, and there were enough young Condors being successfully bred in captivity to begin planning for a reintroduction back to the wild. In 1991 and 1992, captive-bred Condors were released in California, and survived. For the first time in years, there were once again wild Condors. Subsequent releases have led to wild populations in the Pinnacles National Monument, Sespe Condor Refuge, and the Los Padres National Forest. All captive-bred Condors are tagged with individual numbers, which allows them to be tracked and studied.

This success led to the release of three Condors on the Baja Peninsula in 1992, and then to the establishment of another captive conservation center in Arizona. In December 1996 six captive-bred Condors were reintroduced into the Vermilion Cliffs area near the Grand Canyon. The wild Arizona population of released Condors now numbers about 75 birds, which have spread into southern Utah. In 2003 the reintroduced birds began reaching breeding age, and at least 45 chicks are now known to have been successfully fledged in the wild.

Today, the world’s population of California Condors has grown from just 22 birds to almost 450, with about 250 of these living in the wild. It has been confirmed that the released captive-bred birds are successfully hatching and raising chicks throughout their range, and some of these second-generation birds have now also begun breeding. Although the population is still vulnerable (lead poisoning remains a particular danger, and efforts are being made to ban lead hunting ammunition in areas where the birds live), the Condor has become one of our biggest conservation success stories.

 

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