Andean condor
The Andean condor is a South American New World vulture and is the only extant member of the genus Vultur. It is found in the Andes mountains and adjacent Pacific coasts of western South America. With a maximum wingspan of and weight of, the Andean condor is one of the largest flying birds in the world, and is generally considered to be the largest bird of prey in the world.
One of two species commonly referred to as condors, it is a large black vulture with a ruff of white feathers surrounding the base of the neck and, especially in the male, large white patches on the wings. The head and neck are nearly featherless, and are a dull red color, which may flush and therefore change color in response to the bird's emotional state. In the male, there is a wattle on the neck and a large, dark red comb or caruncle on the crown of the head. The female condor is smaller than the male, an exception to the usual sexual dimorphism seen in birds of prey.
The condor is primarily a scavenger, feeding on carrion. It prefers large carcasses, such as those of deer or cattle. It reaches sexual maturity at five or six years of age and nests at elevations of up to, generally on inaccessible rock ledges. One or two eggs are usually laid per clutch. It is one of the world's longest-living birds, with a lifespan of over 70 years in some cases.
The Andean condor is a national symbol of Bolivia, Chile, Colombia, Ecuador, and Peru and plays an important role in the folklore and mythology of the Andean regions. The Andean condor is considered vulnerable by the IUCN. It is threatened by habitat loss and by secondary poisoning from lead in carcasses killed by hunters. Captive breeding programs have been instituted in several countries.
Taxonomy and systematics
The Andean condor was described by Swedish scientist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae and retains its original binomial name of Vultur gryphus.Etymology
The Andean condor is sometimes called the Argentinean condor, Bolivian condor, Chilean condor, Colombian condor, Ecuadorian condor, or Peruvian condor after one of the nations to which it is native. The generic term Vultur is directly taken from the Latin vultur or voltur, which means "vulture". Its specific epithet is derived from a variant of the Greek word γρυπός. The word condor itself is derived from the Quechua kuntur.Phylogeny
The exact taxonomic placement of the Andean condor and the remaining six species of New World vultures remains unclear. Although New World and Old World vultures are similar in appearance and have similar ecological roles, they are not closely related, having evolved from different ancestors in different parts of the world. The difference between the two is currently under debate, with some earlier authorities suggesting that the New World vultures are more closely related to storks. More recent authorities maintain their overall position in the order Accipitriformes along with the Old World vultures or place them in their own order, Cathartiformes. The South American Classification Committee has removed the New World vultures from Ciconiiformes and instead described them as incertae sedis, but notes that a move to Falconiformes or Cathartiformes is possible.Fossil record
The Andean condor is the only accepted living species of its genus, Vultur. Unlike the California condor, which is known from extensive fossil remains and some additional ones of congeners, the fossil record of the Andean condor recovered to date is scant. Presumed Plio-Pleistocene species of South American condors were later recognized to be not different from the present species, although one known only from a few rather small bones found in a Pliocene deposit of Tarija Department, Bolivia, may have been a smaller palaeo subspecies, V. gryphus patruus.Distribution and habitat
The Andean condor is found in South America in the Andes and the Santa Marta Mountains. In the north, its present range begins in Venezuela and Colombia, where it is extremely rare, then continues south along the Andes in Ecuador, Peru, and Chile, through Bolivia and western Argentina to the Tierra del Fuego. However, its historic range was greater; in the early 19th century, the Andean condor bred from western Venezuela to Tierra del Fuego, along the entire chain of the Andes. Its range was significantly reduced due to human activity.Its habitat is mainly composed of open grasslands and alpine areas up to in elevation. It prefers relatively open, non-forested areas which allow it to spot carrion from the air, such as the páramo or rocky, mountainous areas in general. It occasionally ranges to lowlands in eastern Bolivia, northern Peru, and southwestern Brazil, descends to lowland desert areas in Chile and Peru, and is found over southern-beech forests in Patagonia. In southern Patagonia, meadows are important for Andean condors as this habitat is likely to have herbivores present. In this region, Andean condor distributions are therefore influenced by the locations of meadows as well as cliffs for nesting and roosting.
Description
The overall length of the Andean condor can range from. Among standard measurements, the wing chord is, the tail is and the tarsus is. Measurements are usually taken from specimens reared in captivity. The mean weight is, with the males averaging about a kilogram more at, the females a kilogram less at. Condors possess the heaviest average weight for any living flying bird or animal, ahead of trumpeter swans and Dalmatian pelicans. However, other sources claim a mean species body mass of for the Andean condor. The Andean condor is the largest living land bird capable of flight if measured in terms of average weight and wingspan, although male bustards of the largest species can weigh more. The mean wingspan is around and the wings have the largest surface area of any extant bird. It has a maximum wingspan of. Among living bird species, only the great albatrosses and the two largest species of pelican exceed the Andean condor in average and maximal wingspan.The adult plumage is all black, except for a frill of white feathers at the base of the neck and, especially in the male, large white bands on the wings, which only appear after the bird's first moult. The head and neck, kept meticulously clean, are red to blackish-red, and have few feathers. Their baldness means the skin is more exposed to the sterilizing effects of dehydration and high-altitude UV light. The crown of the head is flattened, and is topped by a dark red comb ; the skin hanging from its neck is called a wattle. Males also have yellower skin. When condors are agitated, their head and neck flush, a clear signal to animals nearby. This flush of colour is especially intense in dominant males when feeding at carcasses, and can happen in just a few seconds. Juveniles are grayish-brown, but with a blackish head and neck, and a brown ruff.The middle toe is greatly elongated, and the hind one is only slightly developed, while the talons of all the toes are comparatively straight and blunt. The feet are thus more adapted to walking, and are of little use as weapons or organs of prehension as in birds of prey and Old World vultures. The beak is hooked, and adapted to tear rotting meat. The irises of the male are brown, while those of the female are deep red. They have no eyelashes. Unlike the case with most other birds of prey, the female is smaller.
Observation of wing color patterns, and the size and shape of the male's crest, are the best ways of identifying individual Andean condors. Sighting-resighting methods assess the size and structure of populations.
Ecology and behavior
The condor soars with its wings held horizontally and its primary feathers bent upwards at the tips. The lack of a large sternum to anchor its correspondingly large flight muscles physiologically identifies it as primarily being a soarer. It flaps its wings on rising from the ground, but after attaining a moderate elevation it flaps its wings very rarely, relying on thermals to stay aloft. In The Voyage of the Beagle, Charles Darwin mentioned watching condors for half an hour without once observing a flap of their wings. It prefers to roost on high places from which it can launch without major wing-flapping effort. Andean condors are often seen soaring near rock cliffs, using the heat thermals to aid them in rising in the air. Flight recorders have shown that "75% of the birds' flapping was associated with take-off", and that it "flaps its wings just 1% of the time during flight". The proportion of time for flapping is more for short flights. Flapping between two thermal glides is more than flapping between two slope glides.Like other New World vultures, the Andean condor has the unusual habit of urohidrosis: it often empties its cloaca onto its legs and feet. A cooling effect through evaporation has been proposed as a reason for this behavior, but it does not make any sense in the cold Andean habitat of the bird. Because of this habit, their legs are often streaked with a white buildup of uric acid.
There is a well-developed social structure within large groups of condors, with competition to determine a 'pecking order' by body language, competitive play behavior, and vocalizations. Generally, mature males tend to be at the top of the pecking order, with post-dispersal immature males tending to be near the bottom.
Breeding
Sexual maturity and breeding behavior do not appear in the Andean condor until the bird is five or six years of age. It may live to 50 years or more, and it mates for life. During courtship displays, the skin of the male's neck flushes, changing from dull red to bright yellow, and inflates. He approaches the female with neck outstretched, revealing the inflated neck and the chest patch, while hissing, then extends his wings and stands erect while clicking his tongue. Other courtship rituals include hissing and clucking while hopping with wings partially spread, and dancing.The Andean condor prefers to roost and breed at elevations of. Its nest, which consists of a few sticks placed around the eggs, is created on inaccessible ledges of rock. However, in coastal areas of Peru, where there are few cliffs, some nests are simply partially shaded crannies scraped out against boulders on slopes. It deposits one bluish-white egg, weighing about and ranging from in length. Breeding occurs about every second year, in the southern Andes around October, in the central and northern Andes it can be throughout the year. The egg hatches after 54 to 58 days of incubation by both parents. If the chick or egg is lost or removed, another egg is laid to take its place. Researchers and breeders take advantage of this behavior to double the reproductive rate by taking the first egg away for hand-rearing, causing the parents to lay a second egg, which they are generally allowed to raise. The young are covered with a grayish down until they are almost as large as their parents. They are able to fly after six months, but continue to roost and hunt with their parents until age two, when they are displaced by a new clutch.