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. Description 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. Subspecies There are four subspecies: Pseudastur albicollis ghiesbreghti – Southern Mexico to Nicaragua Entirely white, except for black markings on the outer primaries, and a black sub-terminal tail bar. The eyes are yellow. Pseudastur albicollis costaricensis – Honduras to Panama and Colombia. Similar to ghiesbreghti but with more distinct black markings on the wings and tail. The eyes are brown. Pseudastur albicollis williaminae – Locally in north-western Colombia and western Venezuela. Wing feathers are more heavily marked with black, and it has black streaks on the crown and collar. The tail band is broader and the eyes are brown. Pseudastur albicollis albicollis – Northern Colombia and central Venezuela to Brazil. Smaller than the northern forms and the wings are mostly black, with white markings. The black tail band extends to the base of the tail and the eyes are brown. All subspecies look mainly white from below. The identity of the birds discovered in 2000/2001 in the Serranía de las Quinchas of central Colombia is unclear. Systematics 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