Schwarzschwanztyrann

Bestimmung

This is a robust, short-tailed bird with a long, hook-tipped bill; like other tityras, it has a peculiar vestigial ninth primary feather. The adult black-tailed tityra is 20–22 centimetres (7.9–8.7 in) long and weighs 60–70 grams (2.1–2.5 oz). The male is dull white above and white below. The rectrices, the primary and secondary remiges and a cap extending to below the eyes are black; the tertiary remiges are silvery grey. Females have dark brown rather than black on wings and tail and some brown pattern on head, back and underside. In both sexes, there is a patch of rosy-red bare skin around the eye, extending to the bill which is red-based with a black tip. The iris and feet are dark. The juvenile plumage is unknown.<p>This species has a buzzing short call rendered as ed, rek, urd or wenk. A double beeza-buzza and triple weenk, weenk, weenk are also given. It more frequently calls in flight than when perched.

Taxonomie

In 1760, the French zoologist Mathurin Jacques Brisson included a description of the black-tailed tityra in his Ornithologie based on a specimen collected in Cayenne in French Guiana. He used the French name La pie-griesche gris de Cayenne and the Latin name Lanius Cayanensis cinereus. Although Brisson coined Latin names, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature. When Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition in 1766, he added 240 species that had been previously described by Brisson. One of these was the black-tailed tityra. Linnaeus included a brief description, coined the binomial name Lanius cayanus and cited Brisson's work. The species is now placed in the genus Tityra, which was introduced by the French ornithologist Louis Pierre Vieillot in 1816.<p>Two subspecies are recognized; they are sometimes treated as distinct species but widely intergrade where their ranges meet:

Wissenschaftlicher Name

Tityra cayana

Autorität

(Linnaeus, 1766)

Ordnung

Passeriformes

Familie

Tityridae

Gattung

Tityra

Verbreitung und Lebensraum

This bird is found as a year-round resident in forest edges, second growth and plantation shade trees in the pantanal and cerrado as well as in terra firme and várzea forest, usually below 500 metres (1,600 ft) but occasionally as far up as 1,100 metres (3,600 ft) ASL.

Zugverhalten

Complete migrants

Verhalten

Black-tailed tityras are most commonly seen in pairs, or, less frequently, single or in small groups; they are intolerant of other birds and will try to chase them away. They are often seen perched conspicuously as they feed on medium-sized fruits. Food is gleaned from vegetation or picked off in mid-hover. While some large insects are caught, these are mainly fed to young birds; adults are predominantly frugivores and locally important dispersers of such species as the Meliaceae Cabralea canjerana. This species rarely attends mixed-species feeding flocks even when provisioning young, preferring to forage for insects on its own high up in the trees.<p>Its main breeding season appears to be from November to March across its range, but occasional nesting birds can be encountered almost year-round at least in some regions. For example, in the lowlands of Colombia and Ecuador, breeding activity has been reported in June and July also, suggesting either lack of a distinct breeding season and/or that two broods may be raised per year. The nest is several meters above ground in a tree hole, such as an old woodpecker nest or the crown of a dead palm tree. The brown-marked buff eggs are laid in a bed of dry leaves and some small twigs. Three eggs are considered likely, but exact clutch size is uncertain. Only the female incubates for almost three weeks until the young hatch, but both parents feed the chicks. Fledging is believed to take at least 3 weeks, perhaps as much as one month.<p>This species is one of the many hosts of the brood parasitic shiny cowbird (Molothrus bonariensis). It is not uncommon across its large range and occurs in many national parks and other protected areas. Therefore, it is considered a species of least concern by the IUCN.

Schutzstatus

Bestandstrend

declining