Monday, July 16, 2012

The California Condor

            The Critically Endangered California Condor is a member of the New World vulture family, and has an impressive wingspan of just less than three metres. The featherless head and neck are a reddish-orange colour; a few black feathers sprout from the head and there is a ruff of fine, glossy black feathers around the neck. The neck has an inflatable pouch, which is important in courtship. The plumage is black in colour with large white patches under each wing. Males and females are indistinguishable by size or plumage. Juveniles are grey and adult feathers do not replace this down until the age of five to seven months. Sub-adults retain a grey head until they reach maturity at five to seven years of age, when they acquire the full colouration of an adult.

Scientific Classification
G. californianus

Other Names
California Condor
Condor de Californie
Kalifornischer Kondor
Cóndor de California
Californisk Kondor

            Classified as Critically Endangered (CR) by the IUCN Red List, and listed on Appendix I of CITES.

            There are currently 104 adults in the wild that are old enough to breed, and 44 have produced viable offspring (2010). As mature individuals as defined by IUCN only includes individuals in the wild that are currently capable of reproduction, and re-introduced individuals must have produced viable offspring before they are counted as mature individuals, the current global population senses of  IUCN is 44 mature individuals. The wild population currently numbers 213 individuals in total (2012).

            Its range includes rocky, open-country scrubland, coniferous forest and oak savannah. Cliffs, rocky outcrops or large trees are used as nest sites. It scavenges on the carcasses of large mammals and also feeds on the carcasses of small mammals, but perhaps only where there are sufficient numbers at one site. Released birds have become increasingly independent in finding food and may range more than 400 km from release sites.

            The California condor was originally widespread throughout North America, but by the 1800s they were restricted to the west coast, from British Columbia to Baja California. In the 1970s only 30 individuals remained, all of which were confined to a small area of California, and on Easter Sunday 1987 the species became Extinct in the Wild when the last individual was taken into captivity. An extensive conservation effort has been undertaken to re-introduce captive-bred condors back into the wilds of California, Arizona and Mexico.

            Wild condors inhabit large territories, often traveling 250 km a day in search of carrion. It is thought that in the early days of its existence as a species, the California condor lived off the carcasses of the "megafauna", which are now extinct in North America. They still prefer to feast on large, terrestrial mammalian carcasses such as deer, goats, sheep, donkeys, horses, pigs, cougars, bears, or cattle. Alternatively, they may feed on the bodies of smaller mammals, such as rabbits or coyotes, aquatic mammals such as whales and California Sea Lions, or salmon. Bird and reptile carcasses are rarely eaten. Since they do not have a sense of smell, they spot these corpses by looking for other scavengers, like eagles and smaller vultures, the latter of which cannot rip through the tougher hides of these larger animals with the efficiency of the larger condor. They can usually intimidate other scavengers away from the carcass, with the exception of bears, which will ignore them, and Golden Eagles, which will fight a condor over a kill or a carcass. In the wild they are intermittent eaters, often going for between a few days to two weeks without eating, then gorging themselves on 1–1.5 kilograms of meat at once.

            Condors begin to look for a mate when they reach sexual maturity at the age of six. To attract a prospective mate, the male condor performs a display. In the display, the male turns his head red and puffs out his neck feathers. He then spreads his wings and slowly approaches the female. If the female lowers her head to accept the male, the condors become mates for life. The pair makes a simple nest in caves or on cliff clefts, especially ones with nearby roosting trees and open spaces for landing. A mated female lays one bluish-white egg every other year. Eggs are laid as early as January to as late as April. The egg weighs about 280 g and measures from 90–120 mm in length and about 67 mm in width. If the chick or egg is lost or removed, the parents "double clutch", or lay another egg to take the lost one's place. Researchers and breeders take advantage of this behaviour to double the reproductive rate by taking the first egg away for puppet-rearing; this induces the parents to lay a second egg, which the condors are sometimes allowed to raise.

Adults in captivity begin to breed at six to eight years of age, and pairs mate for life, producing one chick every two years. California condors, like many New World vultures engage in an unusual behaviour known as 'urohydrosis' in order to keep cool. This involves urinating on their own legs, which takes heat away from their body through evaporation; the cooled blood is then circulated back through the body.

The eggs hatch after 53 to 60 days of incubation by both parents. Chicks are born with their eyes open and sometimes can take up to a week to hatch from their egg. The young are covered with a greyish down until they are almost as large as their parents. They are able to fly after five to six months, but continue to roost and forage with their parents until they are in their second year, at which point the parents typically turn their energies to a new nest.

            The original decline of the California condor followed the extinction of many large mammals in North America. Despite legal protection since 1900, the 20th Century decline was due to human induced pressures such as trapping, shooting, egg collection and lead poisoning following ingestion of carcasses killed with lead shot. Unfortunately lead poisoning still occurs regularly and remains the condor's greatest threat; other current threats include collisions with power lines, shooting, and both deliberate and accidental poisoning.

Conservation Measures
            Towards the end of the 1980s, with only eight individuals left in the wild, it was clear that the extinction of this bird was imminent. The remaining wild individuals were taken into captivity and incorporated into an intensive conservation breeding programme run by San Diego Wild Animal Park, Los Angeles Zoo and The Peregrine Fund. A variety of techniques were used in the breeding programme including double-clutching and the rearing of chicks with hand puppets, and in 1992 the first condors were released back into the wild. 

Numerous hurdles have had to be overcome, not least teaching captive birds to avoid power cables, but in the spring of 2002 the first wild condor chick for two decades hatched. The rescue of the Californian condor is an on going conservation programme but the successes so far have been inspiring and the population continues to climb; today the condor can once again be seen soaring over the rocky Californian landscape.


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