Species of bird
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The beautiful nuthatch (Sitta formosa) is a bird species in the family Sittidae, collectively known as nuthatches. It is a large nuthatch, measuring in length, that is not sexually dimorphic. Its coloration and markings are dramatic, the upper parts being black and azure, streaked with white and pale blue on the head and lined with the same colors on the wing feathers. The ;dfn id="" ;underparts ;/dfn ; are orange, and the ;dfn id="" ;eyebrow ;/dfn ; and ;dfn id="" ;throat ;/dfn ; are ochre. An irregular, dark ;dfn id="" ;eyestripe ;/dfn ; highlights its eye. "S. formosa"'s ecology is not fully described, but it is known to feed on small insects and larvae found on the trunks and epiphyte-covered branches of trees in its range. Reproduction takes place from April to May; the nest is placed in the hole of an oak, rhododendron, or other large tree. The nest is made of plant material and fur in which the bird typically lays four to six eggs.
Although the species is found in most of the countries making up the mainland of Southeast Asia, it appears to be rare throughout its range, its population being highly localized where it is found. The bird nests predominantly in montane forest at an altitudinal range from up to nearly , with some seasonal height adjustment, down to around in winter. Its apparent localization within its range makes rigorous estimates of its population difficult, but its habitat is threatened by deforestation and the species appears to be in decline. It has been classified as vulnerable by the International Union for Conservation of Nature.
Taxonomy.
The nuthatches constitute a genus – "Sitta" – of small passerine birds in the family Sittidae, typified by short, compressed wings and short, square 12-feathered ;dfn id="" ;tails ;/dfn ;, a compact body, longish pointed ;dfn id="" ;bills ;/dfn ;, strong toes with long claws, and behaviorally, by their unique head-first manner of descending tree trunks. Most nuthatches have gray or bluish ;dfn id="" ;upperparts ;/dfn ; and a black eyestripe. "Sitta" is derived from the Ancient Greek name for nuthatches, , "sittē". "Nuthatch", first recorded in 1350, is derived from "nut" and a word probably related to "hack", since these birds hack at nuts they have wedged into crevices. The genus may be further divided into seven subgenera,[fn. 1] of which the beautiful nuthatch is placed alone in "Callisitta" (Bonaparte, 1850), and the species is therefore sometimes called "Callisitta Formosa".
The beautiful nuthatch was first described in 1843 by British zoologist Edward Blyth, from a specimen he examined in Darjeeling. Its kinship with other members of the genus is unclear. The bright blue color of its ;dfn id="" ;plumage ;/dfn ; invites a comparison to the blue nuthatch ("S. azurea"), or other blue-tinted nuthatch species such as the velvet-fronted nuthatch ("S. frontalis"), yellow-billed nuthatch ("S. solangiae") and the sulphur-billed nuthatch ("S. oenochlamys"), but its distribution being focused in the eastern Himalayas, and the uniqueness of its plumage, argues against the assumption. According to the International Ornithological Congress and ornithologist Alan P. Peterson, no subspecies have been identified.
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Phylogenetic tree detailNuthatch phylogenic detail according to Pasquet, et al. (2014):
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Citations.
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Bibliography.
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