Tiranno tropicale

Identificazione

An adult tropical kingbird is 22 cm (8.7 in) long, weighs 39 g (1.4 oz) and has a wingspan range of 38–41 cm. The head is pale gray, with a darker eye mask, an orange crown stripe, and a heavy gray bill. The back is grayish-green, and the wing and forked tail are brown. The throat is pale gray, becoming olive on the breast, with the rest of the underparts being yellow. The sexes are similar, but young birds have pale buff edges on the wing coverts.

Tassonomia

The tropical kingbird was formally described in 1819 by the French ornithologist Louis Pierre Vieillot under the binomial name Tyrannus melancholicus. Vieillot based his description on the Suirirí-Guazú that had been described by the Spanish naturalist Félix de Azara in 1805 in his book Apuntamientos para la historia natural de los páxaros del Paragüay y Rio de la Plata. The specific epithet is Latin meaning "melancholic" (that is "bad-tempered").<p>Three subspecies are recognised:

Nome scientifico

Tyrannus melancholicus

Autorità

Vieillot, 1819

Ordine

Passeriformi

Famiglia

Tyrannidae

Genere

Tyrannus

Areale e habitat

Migrazione

Complete migrants

Comportamento

Tropical kingbirds appear to be monogamous. In most parts of the species' range, they are permanent residents and remain together in pairs year-round.(Sibley 2014)[page needed]The call is a high-pitched twittering trill, tree-e-e-e-e-e-e, with a more complex version sung by the male at dawn.<p>Their breeding habitat is semi-open areas with trees and shrubs, including gardens and roadsides. Tropical kingbirds like to observe their surroundings from a prominent open perch, usually high in a tree, undertaking long flights to acrobatically catch insects in mid-air (hawking), sometimes hovering to pick food off vegetation (gleaning). The insects preyed upon include beetles, bees, wasps, termites, butterflies, moths, dragonflies and grasshoppers. They also eat some berries and fruit from such diverse species as tamanqueiro (Alchornea glandulosa), common guava (Psidium guajava), the Annonaceae, Cymbopetalum mayanum and gumbo-limbo (Bursera simaruba); foraging for these even in disturbed habitat. As they keep mainly to the upper levels of trees, they find little profit in following mixed-species feeding flocks in the understory.<p>Aplomado falcons have been known to prey on adult tropical kingbirds, while eggs and young have been attacked by swallow-tailed kites and chestnut-mandibled toucans. These birds aggressively defend their territory against intruders, even much larger birds such as magnificent frigatebirds, toucans, caracaras or hawks. In a study in Parque Nacional de La Macarena of Colombia, parasitism by microfilariae and trypanosomas (presumably T. everetti) was infrequently recorded in tropical kingbirds.<p>The male and female inspect potential sites together before selecting a site, typically a fork or crotch high in a tree (up to 20 m (66 ft) high) but sometimes just a few metres above water.(Sibley 2014)[page needed] The female builds a bulky, sloppy-looking, shallow nest of vines, rootlets, twigs, weeds, and grasses; it is unlined or lined with hair. Nests average about 13.2 cm (5.2 in) across and 7.6 cm (3.0 in) tall, with interior cup about 7.6 cm (3.0 in) across and 4.1 cm (1.6 in) deep.[page needed]<p>The female incubates the typical clutch of two to four eggs for approximately 16 days, and the nestlings fledge in another 18 or 19 days. The eggs are whitish or pale pink with variable amounts of dark blotching.[page needed]

Conservazione

Tendenza della popolazione

rising