sentences:  The small-bodied Wahlberg's eagle ("H. wahlbergi") has been traditionally considered a "Aquila" species due to its lack of change from juvenile to adult plumage and brownish color but it is actually genetically aligned to the "Hieraaetus" lineage.Cassin's hawk-eagle ("H. africanus") is also probably closely related to the "Hieraaetus" group rather than the "Spizaetus/Nisaetus" “hawk-eagle” group (in which it was previously classified) which is not known to have radiated to Africa.There are six extant subspecies of golden eagle that differ slightly in size and plumage.