>Buteo lineatus (Red-shouldered Hawk)

Saturday, February 18, 2012

>Buteo lineatus (Red-shouldered Hawk)

Red-shouldered Hawk

Red-shouldered Hawk

Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Falconiformes (or Accipitriformes, q.v.)
Family:	Accipitridae
Subfamily:	Accipitrinae
Genus:	Buteo
Species:	B. lineatus
Binomial name
*Buteo lineatus* (Gmelin, 1788)

The Red-shouldered Hawk (Buteo lineatus) is a medium-sized hawk. Its breeding range spans eastern North America and along the coast of California and northern to northeastern-centralMexico.

Description

Males are 43 to 58 centimetres (17 to 23 in) long, weigh about 550 g (19 oz) (1.2 lbs) and have a wingspan of 96 cm (38 in). Females are slightly larger at 48 to 61 cm (19 to 24 in) in length, a weight of about 700 g (25 oz), and a wingspan of about 105 cm (41 in). Adults have brownish heads, reddish chests, and pale bellies with reddish bars. Their tails, which are quite long by Buteo standards, are marked with narrow white bars. Red "shoulders" are visible when the birds are perched. These hawks' upper parts are dark with pale spots and they have long yellow legs. Western birds may appear more red, while Florida birds are generally paler. The wings of adults are more heavily barred on the upper side. Juvenile Red-shouldered Hawks are most likely to be confused with juvenile Broad-winged Hawks, but can be distinguished by their long tails, crescent-like wing markings, and a more flapping, Accipiter-like flight style. This bird is often confused with the Red-tailed Hawk.

Taxonomy

The Red-shouldered Hawk is a member of the genus Buteo, a group of medium-sized raptors with robust bodies and broad wings. Members of this genus are known as buzzards in Europe, but hawks in North America.

There are five recognized subspecies of Buteo lineatus, which vary in range and in coloration:

B. l. lineatus (Gmelin, 1788)
B. l. alleni
B. l. elegans
B. l. extimus
B. l. texanus

Behavior

Food and feeding

While in forested areas, these birds typically wait on a perch and swoop down on prey. When in clearings, they sometimes fly low to surprise prey. Small mammals are typically the most important prey, with voles, mice and chipmunks locally favored. Other prey can includeamphibians, reptiles (especially small snakes), small birds, and large insects. They will attack birds as large as pigeons and doves. During winters, they sometimes habituate to preying on birds commonly found at bird feeders. These birds are permanent residents throughout most of their range, though northern birds do migrate, mostly to central Mexico. The major modern threat to these birds is deforestation, which has eliminated these birds as breeders in some areas.

Breeding

The breeding habitats of the Red-shouldered Hawk are deciduous and mixed wooded areas, often near water. While establishing territories, the distinctive, screaming kee-aah call (usually repeated three to four times) of this bird is heard. The breeding pair builds a stick nest in a major fork of a large tree. The clutch size is typically three to four eggs. The blotchy-marked eggs are typically 54.5 × 43 mm (2.15 × 1.7 in). The incubation period can range from 28 to 33 days. The hatchlings, 35 g (1.2 oz) at first, are brooded for up to 40 days. The young leave the nest at about six weeks of age, but remain dependent on the parents until they are 17 to 19 weeks old. Predators of eggs and birds of all ages include Great Horned Owls, Red-tailed Hawks, Peregrine Falcons, raccoons, martens, and fishers (adults are vulnerable to the mammals only while nesting). Red-shouldered Hawks sometimes collaborate and peaceably coexist with American Crows (usually an enemy to all other birds because of their egg-hunting habits) to mob Great Horned Owls and Red-tailed Hawks. The clearing of forests over the last two centuries probably led to decreases in populations, while increasing habitat for the Red-tailed Hawk. Populations appear stable, but may be declining in some areas.