status: Critically endangered, IUCN Endangered, IUCN
range: USA (reintroduced in Arizona and California)
Description and biology
The California condor, or California vulture, is the largest bird in North America and one of the largest flying birds in the world. It measures 45 to 55 inches (114 to 140 centimeters) long and weighs between 20 and 25 pounds (9 and 11 kilograms). It has a wingspan of up to 9.5 feet (2.9 meters), and its plumage (covering of feathers) is a dull gray-black. A diamond-shaped white patch appears on the underside of its wings. The bird's neck and head are bare, and its skin color ranges from gray to orange-red.
Like all vultures, the California condor feeds mainly on carrion (decaying flesh of dead animals), preferring the carcasses of deer, cattle, or sheep. It will also attack and eat rodents, fish, and birds. When searching for food, the condor covers vast distances, sometimes as much as 140 miles (225 kilometers). It soars at speeds of 35 to 55 miles (56 to 88 kilometers) per hour on warm thermal updrafts at altitudes up to 15,000 feet (4,570
meters). When not eating, the condor spends much of its time bathing and preening (smoothing feathers).
California condors do not begin breeding until they are between five and eight years old. Once paired, a male and female condor mate for life. Mating takes place during the winter, with the female laying one large egg. Both parents incubate (sit on or brood) the egg for 50 to 56 days until it hatches. The young condor fledges (develops flying feathers) within six months, but may remain dependent on its parents for more than a year. Because of this, male and female pairs usually breed once every two years.
Habitat and current distribution
California condors prefer to nest in caves or on rocky cliffs in mountainous terrain and to roost (rest or sleep) on tall, exposed trees and rocky outcrops. They feed on nearby open grasslands or savannas.
The last 9 wild California condors were taken into captivity in 1987, making a total of 27 condors in the world, all in captivity. Five years later, eight captive-bred birds were released into the wild in California at the Sespe Condor Sanctuary in the Los Padres National Forest. In December 1996, six young California condors were released in the Vermillion Cliffs, a remote part of the Glen Canyon National Recreation Area in northern Arizona. Other releases have occurred in Lion Canyon and Castle Crags, two remote regions of the Los Padres National Forest in Santa Barbara County, California; and in the Ventana Wilderness Sanctuary near Big Sur on the coast of northern California. From the 27 condors that were taken into captivity in 1987, the population of condors in 2000 was 155 condors; 56 of them were living in the wild.
History and conservation measures
Currently one of the rarest birds in North America, the California condor ranged over the entire continent for thousands of years. It fed on the remains of large Ice Age mammals such as mammoths and camels. Around 8000 B.C., when these mammals became extinct, the number of condors began to decline. By the time Europeans began colonizing North America in the seventeenth century, the bird's range was already reduced to the western coast and mountains. In the nineteenth century, the condor population rapidly declined as settlers moved west. By the mid-twentieth century, the birds numbered less than 100 and were restricted to a small area in central California. By the mid-1980s, only five breeding pairs remained in the wild.
Many factors have led to the California condor's decline in modern times. Because it feeds on the remains of other animals, it is susceptible to poisoning. Poisons ingested by animals become highly concentrated in the predators that eat them. Many condors have died from eating the remains of animals that had ingested pesticides or that had been deliberately poisoned by farmers and ranchers. Others have perished by ingesting lead bullets from the carrion of animals shot by hunters. Condors have also been hunted themselves and have had their eggs stolen from their nests by collectors. As is the case with many other endangered species, the condor's habitat and feeding range has been reduced by human development.
Beginning in 1986, researchers decided to remove the remaining California condors from the wild and place them in captive-breeding programs. The condors bred well in captivity. In the early 1990s, researchers started reintroducing captive- bred condors into the wild. Most of the birds released have slowly adapted to their new environment. In April 2002, the first baby condor born in the wild hatched from its shell in Ventura County. On May 1, 2002, the last wild condor to be taken into captivity back in 1987, a 22-year-old bird, was released back to the wilderness in Los Padres National Forest after spending 15 years in captivity and becoming the father of 16 baby condors. Scientists hoped that the released condors could remember enough about life in the wild to show the ropes to released condors that had been born in captivity.
The goal of the condor reintroduction program is to establish separate condor populations in the wild of at least 150 birds each. Despite its initial success, the program remains controversial. In hopes that the condors will stay in their sanctuary and not eat poisoned animals, biologists (people who study living organisms) often leave deer and cattle carcasses for the birds to eat. Some scientists and researchers believe this prevents the condors from surviving entirely on their own.
In addition to the San Diego Wild Animal Park and the Los Angeles Zoo, California condors are also kept in captivity at the World Center for Birds of Prey in Boise, Idaho.