 The subfamily Circinae has traditionally included the genera "Polyboroides" and "Geranospiza" which include three species - the Madagascan harrier-hawk, ("Polyboroides radiatus"), the African harrier-hawk, ("Polyboroides typus") and the crane hawk, ("Geranospiza caerulescens").This may however not be a valid subfamily as the monophyletic genus "Circus" is nested within the "Accipiter" groups while the other two genera are non-monophyletic and are part of the larger Buteonine clade.Many species in the genus "Circus" show very low diversity in their mitochondrial DNA due perhaps due to extreme drops in their populations.