Prairie Falcon - Systematics

Systematics

The Prairie Falcon outwardly resembles the Peregrine as well as the Old World "hierofalcons", especially the Saker Falcon. It was often considered the only New World member of the latter group. However, this is implausible for reasons of biogeography, and more recently, Falco mexicanus is considered an early aridland offshoot of the Peregrine Falcon lineage, much as the hierofalcons represent a later divergence that similarly adapted to arid habitat. Thus, the similarities between the Prairie Falcon and the hierofalcons are a good example of convergent evolution, the present species and such Old World forms as the Saker and Lanner Falcons being not close relatives but ecological equivalents.