Common Kestrel - Evolution and Systematics

Evolution and Systematics

This species is part of a clade that contains the kestrel species with black malar stripes, a feature which apparently was not present in the most ancestral kestrels. They seem to have radiated in the Gelasian (Late Pliocene, roughly 2.5-2 mya, probably starting in tropical East Africa, as indicated by mtDNA cytochrome b sequence data analysis and considerations of biogeography. The Common Kestrel's closest living relative is apparently the Nankeen or Australian Kestrel (F. cenchroides), which probably derived from ancestral Common Kestrels settling in Australia and adapting to local conditions less than one million years ago, during the Middle Pleistocene.

The Rock Kestrel may be a distinct species F. rupicolus, more distantly related to the Common Kestrel proper than the Nankeen Kestrel; its relationship to the other African and South Asian kestrel taxa remains insufficiently studied. The Canary Islands subspecies are apparently independently derived from Continental birds.

The Lesser Kestrel (F. naumanni), which much resembles a small Common Kestrel with no black on the upperside except wing and tail tips, is probably not very closely related to the present species, and the American Kestrel (F. sparverius) is apparently not a true kestrel at all. Both species have much grey in their wings in males, which does not occur in the Common Kestrel or its close living relatives but does in almost all other falcons.