Ақ қанатты бүркіт (Pseudastur albicollis)

Species of bird
the bird

The white hawk (Pseudastur albicollis) is a bird of prey breeding in the tropical New World of the family Accipitridae. Though it is commonly placed in the subfamily Buteoninae, the validity of this group is doubtful and currently under review.

The adult white hawk ranges from 46–56 cm (18–22 in) long with very broad wings and has a white head, body and underwings. The upper wings are black, and the very short tail is black with a broad white band. The bill is black and the legs are yellow. The sexes are similar, but females are larger and heavier—840 g (1.85 lb) compared to the male's 650 g (1.43 lb). Immature birds have extensive black spotting on the upperparts and dark streaked whitish underparts. The call of the white hawk is a plaintive kerwee.

The white hawk was described by John Latham: in English (1787) as the "white necked falcon", and in Latin (1790) as Falco albicollis, with locality "Cayenne". Around 1850, Edward Blyth created the genus Pseudaster, with "Falco pæcilonotus Cuvier" as the type and "F. skotopterus Pr. Max." as a synonym. In his Genera of Birds, Gray treats them both as Buteos, listing B. albicollis in the main text and B. pæcilonotus in the index. Peters' influential 1931 checklist placed the white hawk in Kaup's genus Leucopternis, listing five subspecies: L. albicollis albicollis, L. a. ghiesbrechti, L. a. costaricensis, L. a. occidentalis, and L. a. polionota. During the 20th century, some authors treated the grey backed hawk occidentalis as a subspecies of L. albicollis, whilst others recognized it as a separate species. In the first decade of the 2000s Leucopternis was found to be polyphyletic, and in 2012 the American Ornithologists' Union separated the white hawk and its relatives under the old name Pseudaster. DNA analysis found that the subspecies P. a. albicollis is sister to P. a. polionotus, and the trans Andean P. a. ghiesbreghti and P. a. costaricensis are more closely related to P. occidentalis than they are to P. a. albicollis. Researchers have documented the white hawk feeding on a number of bird species including the keel billed toucan, the mottled owl, the white breasted wood wren and the great tinamou. This species is often seen soaring, and has a spectacular aerial courtship display. It builds a large stick platform nest in a tree and usually lays one dark blotched blue white egg. An attended nest was observed in Ecuador in mid August.