|Adult at Selous Game Reserve, Tanzania|
The African harrier-hawk, harrier hawk, or gymnogene (Polyboroides typus) is a bird of prey. It is about 60–66 cm in length, and is related to the harriers. It breeds in most of Africa south of the Sahara. The only other member of the genus is the allopatric Madagascan harrier-hawk (Polyboroides radiatus).
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. Genders 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 knees it possesses, which enable it to reach into otherwise inaccessible holes and cracks for prey. A comparable leg-structure and behavior can be found in the Neotropical crane hawk; a case of convergent evolution.
The call is a whistled sueee-sueee-sueee.
The African harrier-hawk can be found in natural woodland, tree plantations and urban areas.
It builds a stick nest in the fork of a tree or the crown of a palm tree. The clutch is one to three eggs.
The African harrier-hawk is omnivorous, eating the fruit of the oil palm as well as hunting small vertebrates. Its ability to climb, using wings as well as feet, and its long double-jointed legs, enable this bird to raid the nests of cavity-nesters such as barbets and woodhoopoes for fledglings. It has been known to prey on introduced species such as feral pigeons, house sparrows and eastern gray squirrels.
Hunting at a weaver bird nest in Etosha National Park
- BirdLife International (2012). "Polyboroides typus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Little, Rob. "Lighting Strike: African Harrier-Hawks in Cape Town". Retrieved 29 June 2013.
- "Polyboroides typus (African harrier-hawk, Gymnogene)". Retrieved 29 June 2013.
- Birds of The Gambia by Barlow, Wacher and Disley, ISBN 1-873403-32-1
- (African harrier-hawk = ) Gymnogene - Species text in The Atlas of Southern African Birds