The African harrier-hawk, harrier hawk or gymnogene (Polyboroides typus) is a bird of prey. It is about in length. It breeds in most of Africa south of the Sahara. The only other member of the genus is the allopatric Madagascar harrier-hawk (Polyboroides radiatus).
Distribution and habitat
African harrier-hawks are a common raptorial species south of the Sahara being most commonly found in the tropical regions of western Africa becoming less common in East and South Africa.
African harrier-hawks are adaptable in their habitat preferences, occupying the following habitats in the Dzanga-Sangha Special Reserve in the Central African Republic: thick rainforest, forest edge, riparian areas, agricultural land and human occupied areas. African harrier-hawks are adaptable and able to live in both urban and rural human occupied areas and they are one of the most common raptorial species in traditional rural villages of eastern Guinea-Bissau. African harrier-hawks have also been known to breed in Palm trees present in cities and urban gardens.
Description
The African harrier-hawk is a medium-sized raptor. The upperparts, head and breast are pale grey. The belly is white with fine dark barring. The broad wings are pale grey with a black trailing edge fringed with a narrow white line. The tail is black with a single broad white band. There is a bare facial patch of variable colour, usually red or yellow. Sexes are similar, but young birds have pale brown instead of grey, and dark brown replacing black. An unusual trait of this species is the double-jointed ankles it possesses, which enable it to reach into otherwise inaccessible holes and cracks for prey. A comparable leg-structure and behaviour can be found in the Neotropical crane hawk as well as the extinct Australian Pengana; a case of convergent evolution.
The call is a whistled '.
Biology
Breeding
Breeding season
The breeding season starts at different times in different parts of African harrier-hawk distribution. In Nigeria the breeding season is in March–August
Nests and nesting
Nest sites are most commonly in large trees Nests are made of sticks and are lined with leaves from trees neighbouring the nest.
Foraging techniques
African harrier-hawks have been identified to employ four different hunting strategies namely: low soaring, high soaring, perch hunting and, canopy and ground foraging.