California Condor

Identificazione

The adult California condor is a uniform black with the exception of large triangular patches or bands of white on the underside of the wings. It has gray legs and feet, an ivory-colored bill, a frill of black feathers surrounding the base of the neck, and brownish red eyes. The juvenile is mostly a mottled dark brown with blackish coloration on the head. It has mottled gray instead of white on the underside of its flight feathers.<p>The condor's head has little to no feathers, which helps keep it clean when feeding on carrion. The skin of the head and neck is capable of flushing noticeably in response to emotional state. The skin color varies from yellowish to a glowing reddish-orange. The birds do not have true syringeal vocalizations. They can make a few hissing or grunting sounds only heard when very close.<p>The female condor is smaller than the male, an exception to the rule among birds of prey (the related Andean condor is another exception). Overall length ranges from 109 to 140 cm (43 to 55 in) and wingspan from 2.49 to 3 m (8 ft 2 in to 9 ft 10 in). Their weight ranges from 7 to 14.1 kg (15 to 31 lb), with estimations of average weight ranging from 8 to 9 kg (18 to 20 lb). Wingspans of up to 3.4 m (11 ft) have been reported but no wingspan over 3.05 m (10.0 ft) has been verified. Most measurements are from birds raised in captivity, so it is difficult to determine if major differences exist between wild and captive condors.<p>California condors have the largest wingspan of any North American bird. They are surpassed in both body length and weight only by the trumpeter swan and the introduced mute swan. The American white pelican and whooping crane also have longer bodies than the condor. Condors are so large that they can be mistaken for a small, distant airplane, which possibly occurs more often than that they are mistaken for other bird species.<p>The middle toe of the California condor's foot is greatly elongated, and the hind toe is only slightly developed. The talons of all the toes are straight and blunt and are thus more adapted to walking than gripping. This is more similar to their supposed relatives the storks than to birds of prey and Old World vultures, which use their feet as weapons or organs of prehension.

Tassonomia

The California condor was described by English naturalist George Shaw in 1797 as Vultur californianus; Archibald Menzies collected the type specimen "from the coast of California" during the Vancouver expedition. It was originally classified in the same genus as the Andean condor (V. gryphus), but, due to the Andean condor's slightly different markings, slightly longer wings, and tendency to kill small animals to eat, the California condor has been placed in its own monotypic genus. The generic name Gymnogyps is derived from the Greek gymnos/γυμνος "naked" or "bare", and gyps/γυψ "vulture", while the specific name californianus comes from its location in California. The word condor itself is derived from the Quechua word kuntur.<p>The exact taxonomic placement of the California condor and the other six species of New World vultures remains unclear. Though similar in appearance and ecological roles to Old World vultures, the New World vultures evolved from a different ancestor in a different part of the world. Just how different the two are is 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 Falconiformes 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 placed them in Incertae sedis, but notes that a move to Falconiformes or Cathartiformes is possible.<p>As of the 51st Supplement (2010) of the American Ornithologists' Union, the California condor is in the family Cathartidae of the order Cathartiformes.<p>The genus Gymnogyps is an example of a relict distribution. During the Pleistocene Epoch, this genus was widespread across the Americas. From fossils, the Floridian Gymnogyps kofordi from the Early Pleistocene and the Peruvian Gymnogyps howardae from the Late Pleistocene have been described. A condor found in Late Pleistocene deposits on Cuba was initially described as Antillovultur varonai, but has since been recognized as another member of Gymnogyps, Gymnogyps varonai. It may even have derived from a founder population of California condors.<p>The California condor is the sole surviving member of Gymnogyps and has no accepted subspecies. However, there is a Late Pleistocene form that is sometimes regarded as a palaeosubspecies, Gymnogyps californianus amplus. Opinions are mixed, regarding the classification of the form as either a chronospecies or a separate species, Gymnogyps amplus. Gymnogyps amplus occurred over much of the bird's historical range – even extending into Florida – but was larger, having about the same weight as the Andean condor. This bird also had a wider bill. As the climate changed during the last ice age, the entire population became smaller until it had evolved into the Gymnogyps californianus of today, although more recent studies by Syverson question that theory.

Nome scientifico

Gymnogyps californianus

Autorità

(Shaw, 1797)

Ordine

Cathartiformes

Famiglia

Cathartidae

Genere

Gymnogyps

Areale e habitat

The California condor lives in rocky shrubland, coniferous forest, and oak savanna. They are often found near cliffs or large trees, which they use as nesting sites. Individual birds have a huge range and have been known to travel up to 250 km (160 mi) in search of carrion.<p>There are two sanctuaries chosen because of their prime condor nesting habitat: the Sisquoc Condor Sanctuary in the San Rafael Wilderness and the Sespe Condor Sanctuary in the Los Padres National Forest.<p>The Los Padres Condor Range and River Protection Act of 1992 expanded existing wilderness by 34,200 hectares (84,400 acres) and designated 127,900 hectares (316,050 acres) of new wilderness that provide habitat for the condor in the Los Padres.

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in aumento.

Tendenza della popolazione

in aumento