A three month old wild-hatched California condor chick that died August 25 has tested positive for West Nile Virus. Nest watchers reported a rapid decline in the health of the three month old chick and a team of biologists, a veterinarian and condor keeper attempted to retrieve it from the nest, however it died before it could be treated. The dead chick was promptly sent to the Pathology Department at the San Diego Zoo for a necropsy. The cause of death is believed to be infection with West Nile Virus, complicated by secondary fungal pneumonia. The condor chick hatched in the wild in Ventura County, California on May 19 of this year.
Both parent birds were inoculated with a West Nile Vaccine in June of 2003 and again in June of 2004. With the exception of chicks hatched in the wild all California condors in captivity and in the wild have been inoculated at least once with a vaccine developed especially for condors called DNA West Nile Vaccine. The condors have not had any adverse reactions to the vaccine and subsequent blood tests have shown antibodies in their blood, a sign that the immune system is responding to fight off the disease.
"We know through testing on captive condors that maternal immunity is transferred to the chicks, what we didn't know was how long it lasted. Because this chick died at just 3 months of age we will attempt to vaccinate wild-hatched chicks in their nests. This will have to be done on a case by case basis providing the nests are accessible," stated Marc Weitzel, Project Leader for Hopper Mountain National Wildlife Refuge Complex, which administers the California Condor Recovery Program.
One other wild chick was hatched in California this year; it was removed from the nest when it appeared to be underdeveloped for its age. The chick had ingested trash (small bits of plastic, metal and glass as well as fabric); the chick underwent surgery to remove the trash and may be released next spring. Trash has been found in several other chicks and has caused the death of two chicks since 2001 when California condors first began breeding in the wild. The first wild chick to survive past fledging in California hatched last year. Three chicks have successfully fledged in Arizona and two additional wild condor chicks hatched this year in Arizona are expected to fledge by November.
There are 125 condors now living in the wild in California, Arizona and Baja, Mexico and 151 in captivity at the Los Angeles Zoo, San Diego Wild Animal Park, the Oregon Zoo and the Peregrine Fund's World Center for Birds of Prey in Boise, Idaho. The goal of the California Condor Recovery Plan is to establish two geographically separate populations, one in California and the other in Arizona, each with 150 birds and at least 15 breeding pairs. The largest bird in North America, condors are scavengers that have soared over mountainous areas of California since prehistoric times, but their numbers plummeted in the 20th Century. Condor numbers declined in part due to loss of habitat and food and from shooting, lead poisoning and toxic substances used to poison predators. Condors were listed as an endangered species in 1967, under a law that pre-dated the existing Endangered Species Act. In 1982, the condor population reached its lowest level of 22 birds, prompting biologists to start collecting chicks and eggs for a captive breeding program. By late 1984, only 15 condors remained in the wild. After seven condors died in rapid succession, it was decided to bring the remaining birds in from the wild for the captive breeding program. In 1992, the Recovery Program began releasing California condors back into the wild.
The U.S. Fish & Wildlife Service is responsible for coordinating the conservation of the California condor, working with the Los Padres National Forest, California Department of Fish and Game, and several private partners. Private organizations and institutions are not just interested observers, but are active and essential participants in the implementation of the recovery program, contributing personnel, expertise, institutional support, and funding. California condor captive breeding programs are operated at San Diego Wild Animal Park, Los Angeles Zoo, The Peregrine Funds World Center for Birds of Prey and most recently the Oregon Zoo. Release programs in California are managed by Ventana Wilderness Society, The US Park Service at Pinnacles National Monument and U.S. Fish and Wildlife Service Hopper Mountain National Wildlife Refuge; the Arizona release is managed by The Peregrine Fund: and the Baja release site by the Zoological Society of San Diego.
The U.S Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 95-million-acre National Wildlife Refuge System, which encompasses 545 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 69 national fish hatcheries, 64 Fish and Wildlife Management offices and 81 ecological services field stations. The agency enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign and Native American tribal governments with their conservation efforts. It also oversees the Federal Assistance program, which distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies. For more information about the U.S. Fish and Wildlife Service and condors, visit our home page at http://hoppermountain.fws.gov
