The Accipitridae () is one of the four families within the order Accipitriformes, and is a family of small to large birds of prey with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-sized mammals, with a number feeding on carrion and a few feeding on fruit. The Accipitridae have a cosmopolitan distribution, being found on all the world's continents (except Antarctica) and a number of oceanic island groups. Some species are migratory. The family contains 256 species which are divided into 12 subfamilies and 75 genera.
Many well-known birds of prey such as buzzard, eagles, harriers, hawks, kites, and Old World vultures are included in this group. The osprey is usually placed in a separate family (Pandionidae), as is the secretary bird (Sagittariidae); the New World vultures are also usually now regarded as a separate family (Cathartidae) or order. Karyotype data indicate the accipitrids analysed are indeed a distinct monophyletic group.
Systematics and phylogeny
In the past the accipitrids have been variously divided into some five to ten subfamilies. Most share a very similar morphology, but many of these groups contain taxa that are more aberrant. These were placed in their respective position more for lack of better evidence than anything else. The phylogenetic layout of the accipitrids was historically a matter of dispute. Molecular studies have removed the phylogenetic uncertainty for most of the species.
The accipitrids are recognizable by a peculiar rearrangement of their chromosomes. Apart from this, morphology and mtDNA cytochrome b sequence data give a confusing picture of these birds' inter-relationships. The hawks, kites, eagles and Old World vultures as presently assigned in all likelihood do not form monophyletic groups.
The genus level cladogram of the Accipiridae shown below is based on a densely sampled molecular phylogenetic study of the Accipitridae by Therese Catanach and collaborators...
