Cerchneis Boie, Isis, 1826, p. 976.
Type, Falco rupicolus Daud. South Africa.
This genus is now often lumped together with Erythropus in the genus Falco but it differs greatly from the birds of that genus not only in structure but in habits. The Kestrels are birds of less powerful flight, with weaker implements of prey in their feebler bills and feet and, as we should expect, are hawkers of insects, only tackling small birds and mammals of non-resisting species and these only exceptionally.
In Cerchneis the wing is short and rounded, the second and third primaries subequal; the tail is long and well graduated ; the feet are smaller and weaker than in Erythropus and, a fortiori, than in Falco ; the middle toe without claw equals two-thirds to three-quarters the length of the tarsus and the outer and inner toes are about the same in length.
Key to Species.
A.. Claws black ............... C. tinnunculus, p. 60.
B. Claws yellow............... C. naumanni, p. 65