Spizaetus is the typical hawk-eagle birds of prey genus found in the tropics of the Americas. It was however used to indicate a group of tropical eagles that included species occurring in southern and southeastern Asia and one representative of this genus in the rainforests of West Africa. The Old World species have been separated into the genus Nisaetus. Several species have a prominent head crest. These are medium to large-sized raptors, most being between 55 and 75 cm (23–30 in) long, and tend to be long-tailed and slender. The species that were historically placed in this genus are: