African Harrier-hawk

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 behaviour can be found in the Neotropical crane hawk; a case of convergent evolution. The call is a whistled sueee-sueee-sueee.