Accipitriformes

Accipitriformes
Red-tailed Hawk, Buteo jamaicensis
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Accipitriformes
Families
Accipitridae Cathartidae Pandionidae Sagittariidae

The Accipitriformes is a order that has been proposed to include most of the diurnal birds of prey: hawks, eagles, vultures, and many others, about 225 species in all. For a long time, they have been included with the falcons in the Falconiformes, but because of recent DNA research that suggests falcons are more akin to parrots and passerines,^[1] some ornithologists are now considering classifying the falcons as a separate order and placing the hawks and the rest of the former Falconiformes in the order Accipitriformes.^[2]

The proposed Accipitriformes includes the New World vultures. The placement of these birds has been unclear since the early 1990s.

Characteristics

Accipitriformes are known from the Middle Eocene (the possibly basal genus Masillaraptor from the Messel Pit) and typically have a sharply hooked beak with a cere (soft mass) on the proximodorsal surface, housing the nostrils. Their wings are long and fairly broad, suitable for soaring flight, with the outer 4–6 primaries emarginated.

Accipitriformes have strong legs and feet with raptorial claws and an opposable hind claw. Almost all Accipitriformes are carnivorous, hunting by sight during the day or at twilight. They are exceptionally long-lived, and most have low reproductive rates.

The young have a long, very fast-growing fledgling stage, followed by 3–8 weeks of nest care after first flight, and 1 to 3 years as sexually immature adults. The sexes have conspicuously different sizes and sometimes a female is more than twice as heavy as her mate. This sexual dimorphism is sometimes most extreme in specialized bird-eaters, such as the Accipiter hawks, and borders on non-existent among the vultures. Monogamy is the general rule, although an alternative mate is often selected if one dies.

As delimited in this article, the Accipitriformes are among the most diverse orders in size, from the small sparrowhawks to the condors. The Andean condor has the largest wingspan of any Accipitriformes and one of the largest of all living birds.

Taxomony

Order Accipitriformes

• Accipitridae (buzzards, eagles, harriers, hawks, kites, Old World vultures)
• Cathartidae (New World vultures including condors)
• Pandionidae (Osprey)
• Sagittariidae (Secretary Bird)

References