Xenopsaris albinucha

The white-naped xenopsaris (Xenopsaris albinucha), also known as the reed becard and white-naped becard, is a species of suboscine bird in the family Tityridae, the only member of the genus Xenopsaris. It is found in South America, in humid subtropical and tropical savanna climates in most of the countries east of the Andes: Venezuela, Brazil, Bolivia, Paraguay, Uruguay, and Argentina. Living in open woodland and other open forest habitats, it is mostly sedentary, though some populations may be migratory. The species, which is closely related to becards and tityras, was thought to be either a tyrant-flycatcher or cotinga, before it was placed in Tityridae. The bird is 12.5 to 13 cm (4.9–5.1 in) in length, with whitish undersides, a black crown, and grey-brown upperparts. The sexes are similar in appearance, though the females have duller upperparts. It feeds on insects in the foliage of trees and bushes, and sometimes on the ground. Nesting occurs in a simple cup nest placed in the fork of a tree. Both parents incubate the eggs and help feed the chicks. When the chicks fledge, the parents may divide up the brood to continue helping. The species is not common and little is known about it, but it is not considered in danger of extinction, and has been classified as of least concern by the International Union for Conservation of Nature. The white-naped xenopsaris was described in 1869 by the German-Argentine scientist Hermann Burmeister, based on a specimen collected near Buenos Aires. Burmeister originally placed it in the becard genus, Pachyramphus. It was moved to the monotypic genus Xenopsaris by Robert Ridgway in 1891, but was still known to be closely related to Pachyramphus. A 1989 study of anatomy identified Pachyramphus as a sister taxon to Xenopsaris, but the white-naped xenopsaris was kept in its own genus due to several morphological and behavioural differences, namely its smaller size, the shape of its legs, the length of its primary flight feathers, the lack of strong sexual dimorphism (differences between the sexes) and the construction of the nest. Which family the species belonged to remained unresolved for over a century. According to the Handbook of the Birds of the World, Xenopsaris and its allies were 'taxonomically problematic genera that have for more than a hundred years been shifted back and forth between the cotingas (Cotingidae) and the Tyrannidae'. When placed with the tyrant-flycatchers, Tyrannidae, it was considered closely related to the genera Suiriri, Serpophaga and Knipolegus. The uncertainty was not confined to this species, as there was a general confusion about where to draw the lines between the cotingas, tyrant-flycatchers and manakins. Resolution was provided by the same 1989 study that confirmed the link between Xenopsaris and Pachyramphus. In it, Xenopsaris and six other genera previously held in the three families were found to actually form a fourth family, later named Tityridae. This new family is where the genus is now placed by the South American Classification Committee of the American Ornithological Society. A 2007 study of mitochondrial DNA confirmed the white-naped xenopsaris' place in the Tityridae, and its close relationship to Pachyramphus, as well as the genus Tityra. These three genera were found to be more distantly related to a fourth genus Iodopleura (the purpletufts), although further studies are needed to understand the complete relationship between these four genera. The genus name Xenopsaris was derived from the Ancient Greek word xeno, meaning 'stranger', and Psaris, a synonym for Tiyra, based on the Ancient Greek for starling, described by Georges Cuvier in 1817. The specific name albinucha is from Latin and refers to the bird's white (albus) nape (nuchus). The species is also known as the reed becard, white-naped becard and simply xenopsaris. There are two subspecies of white-naped xenopsaris; the widespread nominate subspecies, and the more restricted X. a. minor of Venezuela, which was described by Carl Eduard Hellmayr in 1920. The white-naped xenopsaris is smaller than the closely related becards and tityras, measuring 12.5 to 13 cm (4.9–5.1 in) in length and weighing around 10 g (0.35 oz). The subspecies X. a. minor has the same plumage as the nominate subspecies, but is smaller; the wing-chord (measurement from the wrist-joint to the end of the wing) length of the nominate subspecies, for example, is 6.4 to 6.6 cm (2.5–2.6 in) compared to 6.0 to 6.2 cm (2.4–2.4 in) in X. a. minor.