California Condor (Gymnogyps Californians) – The Rarest Vulture in the World
Now rarer in the wild than even the Mauritius kestrel, and in some ways more endangered, this magnificent New World vulture, California Condor, really grabbed world headlines in 1986 when its struggle for survival seemed to epitomize the growing conflict between human proliferation and Nature.
After a long and steady decline through many suggested (but largely unproven) factors, it was decided in recent years that the best way to avoid almost certain extinction of California Condor was through a captive-breeding program. Hopefully, this will lead to a release of ‘surplus’ birds into suitable areas once the causes of decline are better understood and significantly halted.
History of California Condor
By October 1986 24 of the known 27 remaining California Condor birds (12 males, 14 females and one unknown) were in captivity, the main method of capture being rocket-propelled nets at meat baits. Capture efforts for the three remaining birds (all radio-marked males) were then in progress. Two of these would join 12 other birds at the San Diego Wild Animal Park and the third would join 12 at Los Angeles Zoo.
An adult captive female was to be transferred from San Diego to Los Angeles for pairing with one of the wild males, as the same pair had bred in the wild in the spring of 1986.
Bird Facts and Information
The California condor (Gymnogyps californianus) is North America’s largest flying landbird with a weight of 8—10.4 kg (18—23 lb) and a wingspan of 2.92 m (9.5 ft).
Its historical range extended from southern British Columbia south through Washington, Oregon and California, generally being found west of the summits of the Cascades and Sierra Nevada, but it has been known as a breeding bird only in California. And even in its recent range, it has been found in less than 20% of the vast area it occupied in the 19th century.
Concern for the condor began early: the 485.64 ha (1,200 acres) Sisquoc Sanctuary was established in 1937 and the 14,164 ha (35,000 acres) Sespe Wildlife Area (later renamed the Sespe Condor Sanctuary) in 1947. But care of birds which forage only for carrion over millions of acres is extremely difficult, especially when all the success achieved on public-owned land is negated by irresponsible actions on private ranches. And while legislation has improved in many directions, law enforcement has been very difficult over such large areas needing regular patrol.
California Condor Bird Habitat
Perhaps the chief failure of California condor habitat management has been the research and control of toxic chemicals used to kill agricultural pests on private rangelands. Strychnine, DDT, compound 1080, cyanide and zinc phosphide have all been or still are common in condor territory.
Condors feed only on the carcasses of dead animals, and before the great herds of mammals were exterminated these probably included deer, elk, pronghorn and smaller species as well as whales and sea lions. But for many years domestic cattle have constituted by far the most important food source for California condors, particularly since sheep farming declined in California.
Recently, however, extensive conversion of rangeland to other more profitable uses has reduced the cattle carcass supply and in the long term, grazing lands could be so diminished and fragmented that revived condor populations may be unable to find sufficient food.
While all known condor nest-sites since 1930 have been on public-owned land, major foraging and roosting areas have been on private range, and this has led to direct persecution of the birds through continued shooting and poisoning until very recently. In an effort to prevent ingestion of meat from poisoned carcasses, the Condor Research Center helpers have been swamping forage areas with ‘clean’ food.
Reason of California condor extinction
Lead toxicosis has been suspected of being a major mortality factor in recent years, though the evidence is inconclusive. The last three known mortalities of wild condors have been through lead poisoning, ingestion of lead bullets from rifle-killed carcasses being a possible route of entry into the body. As well as cattle, condors show a distinct preference for deer carcasses and there is little doubt that many wounded deer carrying bullets or even shotgun pellets have eventually been eaten by condors.
Today fresh carcasses (mainly stillborn dairy cattle) are supplied daily at specific feeding points within the main foraging range to provide the birds with high-quality contaminant-free food. In captivity adult birds are fed chunks of horse-meat supplemented by commercially prepared bird-of-prey and feline mixtures. Young birds are fed chopped-up rats and mice.
The life expectancy of California condors may be as high as 50 years or more in captivity, though very little data exists on the age of wild birds. Age to maturity is approximately six years. In the spring of 1986 a six-year-old male — one of the last three in the wild — successfully mated with a female which has since been captured. This event was considered to be of great biological significance as previously it was believed that the breeding age commenced at 7—11 years.
Birds mate for life and produce a single egg approximately every other year. If the egg is destroyed a second or even a third egg may be laid, and making use of this double and triple-clutching phenomenon field biologists were able significantly to increase the California condor population during the period that wild birds were producing eggs. Thirteen of the birds, currently in captivity, were collected as eggs in the wild and later hatched in zoo incubators.
To date, there have been no successful matings of these condors in captivity, due mainly to the fact that male and female birds have only recently been paired by the zoos. Whether or not these pairings will ultimately prove successful is not known, but agriculturalists experienced in the captive-breeding of the closely related Andean condor (Vultur gryphus) are optimistic that California condors will behave similarly in a captive- breeding program.
There have been no successful reintroductions to the wild so far and there are not likely to be any for some time until targets have been achieved and there are enough ‘surplus’ birds. The Condor Recovery Team, a scientific advisory body to the Fish and Wildlife Service, is currently pondering the issue.
There is certainly great public support for this program and in 1984 and 1985 Congress appropriated $9 million for the acquisition of a 5,670 ha (14,000 acres) critical condor foraging and staging area, which at the moment is also the first choice for a release site. Such an ambitious scheme is essential as once the last birds are removed from the wild there will be less general incentive to protect habitat and consequently reintroduction would be more difficult.
Downtown Los Angeles is less than 75 km (45 miles) from the principal condor nesting areas in Ventura County, but the condor range itself is sparsely populated and is disturbed relatively little now, 36% of the land being in public ownership, Aircraft disturbance and mineral/oil extraction are unlikely to have been significant, but there have been deaths through collision with overhead wires.
Indians once killed many birds for sacrifice and feathers but those days are long gone, as is lawful collection of skins and eggs, and habitat protection and poison/pollution control remain top priorities.
Despite everything, flying California condors show little fear of man and apparently the more conspicuous and noisy a person is the more likely a condor is to approach. Let us hope that the ‘blind faith’ of this magnificent bird is repaid with a permanent place in American skies.