Mantled hawk

The adult of this medium-sized hawk has a bulky appearance with broad "shoulders" relative to total length. The body length measures 470-510mm, with females being slightly larger than males. The head, neck, upper back and entire undersurface except for the black wing tips and basal half of the tail are white. The white round head appears disproportionately large relative to the rest of the body and sometimes projects further than the tail. There are also markings around eyes, giving a masked appearance. The ceres and lores are grey or dull yellow. The bill is pale grey, gradually turning black at the tip. The iris is brown but often appears black in the field. The toes and tarsi are orange-yellow.

The wings, lower back and rump are black or dark bluish grey, with the dark primaries, secondaries, tertials and upper tail coverts having greyish bases with thin white square tips. They also have 3-4 narrow darker bands and the broad white tips form a shallow U when seen from behind. The mantle, scapulars and upper tail coverts are also black or slate grey with broad white tips, but with the coverts appearing darker than the scapulars and are tipped white, sometimes giving a barred appearance.

When perched, the long primaries reach or exceed the tail tip. The long secondaries reach halfway to the tail tip and conceal the rump and base of tail, which makes the tail appear very short.

In flight, this hawk glides on level wings and soars frequently throughout the day, though it is easily spotted when perched at exposed positions at distances over 1 km. When the hawk is seen in flight from below, only the white part of the square tail is visible; but in some individuals, one or two dark bands may be visible at the tail base. Overall, it is similar to the white-necked hawk in its appearance and flight pattern, but has a broad white leading edge on the wings and tail end, whereas this is black in the white-necked hawk. The dark tail base of the latter is however not usually seen in flight, making distinction between these two species difficult in the field.

Flat wing length measurement has been reported as 360-380mm in males, and 390-410mm in females. Other reported measurements include a tail length of 178-222mm, tarsus length of 95.3mm, and culmen length from cere as 29-30mm.

The juvenile is similar to the adult but the plumage is fairly spotted overall, with dark streaks on the white crown and nape which are visible at a distance. The upper wing coverts are fringed whitish and there are dark bars at the base of the tail which are more numerous and noticeable than in adults. The cere ranges from whitish to dull yellow.