Guan crestato

Identificazione

The crested guan is 76 to 91.5 cm (30 to 36 in) long and weighs about 1.6 to 2.4 kg (3.5 to 5.3 lb). Among standard measurements, its wing chord is 33 to 37 cm (13 to 15 in), its tail is 29 to 36 cm (11 to 14 in), and its tarsus is 6.5 to 8.6 cm (2.6 to 3.4 in). It is similar in general appearance to a turkey, with a small head, long strong legs, and a long broad tail. The sexes are similar. Adults of the nominate subspecies are mostly dusky olive brown and have a faint greenish or purplish iridescence. Their belly and crissum are chestnut and the breast and belly feathers have white edges. Their throat has some bristles and its loose skin dangles as a small red wattle. Juveniles resemble adults but overall mottled with blackish brown and with a rufous brown wash on the wing and tail feathers. Both sexes have a red iris, a blackish bill, slaty black bare skin on their face, and red legs and feet. Subspecies P. p. aequatorialis is similar to the nominate, but smaller and more rufescent. Subspecies P. p. brunnescens is more rufescent than the nominate but less so than aequatorialis.

Tassonomia

The crested guan has three subspecies, the nominate P. p. purpurascens (Wagler, 1830), P. p. aequatorialis (Salvadori & Festa, 1900), and P. p. brunnescens (Hellmayr & Conover, 1932).

Nome scientifico

Penelope purpurascens

Autorità

Wagler, 1830

Ordine

Galliformi

Famiglia

Cracidae

Genere

Penelope

Areale e habitat

The nominate subspecies of the crested guan is the northernmost. It is found in Mexico from Sinaloa in the west and southern Tamaulipas in the east and south along the Pacific and Caribbean slopes through Belize and Guatemala into El Salvador and Honduras. Subspecies P. p. aequatorialis is found across much of Nicaragua and south through Costa Rica, Panama, western Colombia, and western Ecuador into far northwestern Peru. Subspecies P. p. brunnescens is found in the Serranía del Perijá where northeastern Colombia and northwestern Venezuela meet, east around Lake Maracaibo, and also in the Venezuelan Coastal Ranges intermittenly from Falcón to Delta Amacuro.<p>The crested guan inhabits a variety of forested landscapes including tropical and subtropical evergreen and deciduous forest, cloudforest, gallery forest, and evergreen montane forest. Most are semi-humid to humid though it occurs locally in drier forest as well. In elevation it is found from sea level to 2,500 m (8,200 ft) in northern Central America, to 1,800 m (5,900 ft) in Costa Rica, to 1,500 m (4,900 ft) in Colombia and Ecuador, to 800 m (2,600 ft) in Peru, and to 1,100 m (3,600 ft) in Venezuela.

Migrazione

Resident species

Comportamento

The crested guan is a year-round resident throughout its range.<p>The crested guan is generally considered to feed on fruit, usually high in the canopy where it takes it directly from the tree, though it will feed at any level including on the ground. It is usually in pairs or loose flocks that quickly and agiley move from limb to limb by jumps and short flights. However, a study on Barro Colorado Island in Panama found that a high percentage of its diet there was young leaves, with insects also making a significant contribution.<p>The crested guan is monogamous. Its breeding season in Costa Rica spans from March to June but is not defined elsewhere. Its nest is a bulky platform of twigs and leaves constructed high in a tree. Its usual clutch size is believed to be two eggs. In captivity its incubation period is about 26 days. Its incubation period, time to fledging, and details of parental care in the wild are not known.<p>The crested guan's dawn song is a "powerful 'steam-whistle' call, ending in a low growl: ku LEEErrr!". It also makes "a loud, honking quonk" and in alarm a series of "extraordinarily loud, honking squawks, quonk, quonk, quonk, rrrrrrrrr". Other vocalizations include "a loud, far-carrying, honking WOK!-WOK!-WOK!-WOK!-WOK!-WOOAK!-WOOAK!-WOOK!...; a piping POK!-POK!-POK!...; and a low, nasal, grunting aahhnk-aahhnk". In the breeding season, at or near dawn males make a display flight during which they drum or whirr their wings.

Conservazione

Tendenza della popolazione

declining