The Red-shouldered Hawk, (Buteo lineatus), is a medium-sized hawk. Their breeding range is in eastern North America and along the coast of California and northern Mexico; also northeastern-central Mexico.

Males are 43 to 58 cm (17 to 23 in) long, weigh about 550 g (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 (1.5 lbs) and a wingspan of about 105 cm (42 in). Adults have a brownish head, a reddish chest and have a pale belly with reddish bars. Their tail, which is quite long by Buteo standards, is marked with narrow white bars. The red "shoulder" is visible when the bird is perched. Their upper parts are dark with pale spots; they have long yellow legs. Western birds may appear more red; Florida birds are generally paler. The wings of adults are heavily barred on the upper side, less so on the underside. Juvenile Red-shouldered Hawks are most likely to be confused with juvenile Broad-winged Hawks, but can be distinguished by their long tail, crescent-like markings on the wings and their more flapping, Accipiter-like flight style.

Usually, while in forested areas, these birds wait on a perch and swoop down on prey. When in clearings, they sometimes flying low in order to surprise prey. Small mammals are typically the most important prey, with voles, mice and chipmunks locally favored. Other prey can include amphibians, reptiles (especially small snakes), small birds and large insects. During winters, they sometimes habituate to preying on more common birds, such as House Sparrows, Mourning Doves and European Starlings, at bird feeders.

Their breeding habitats are deciduous and mixed wooded areas, often near water. It is while establishing territories that the distinctive, screaming kee-aah call (usually repeated 3 to 4 times) of this bird are heard. The breeding pair build a stick nest in a major fork of a large tree. The clutch size is typically 3 to 4 eggs. The blotchy-marked eggs are typically 54.5 x 43 mm (2.1 x 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). Interestingly, Red-shouldered Hawks sometimes collaborate and peaceably co-exist with American Crows (usually an enemy to all other birds because of their egg-hunting habits) in order to mob Great Horned Owls and Red-tailed Hawks.

These birds are permanent residents throughout most of their range; northern birds do migrate however, wintering mostly in central Mexico. The major modern threat to these birds to deforestation, which has eliminated these birds as breeders in some areas.