Its breeding range spans eastern North America and along the coast of California and northern to northeastern-central Mexico.

The red-shouldered hawk was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[3] Gmelin based his account on the "barred-breasted buzzard" of John Latham and the "red shouldered falcon" of Thomas Pennant.

In direct comparison, it is typically larger and longer proportioned than the broad-wing, though is slightly smaller and more slender than most other common North American Buteo species.

That species is larger and bulkier, with more even-sized, broad wings, and is paler underneath, with a reddish tail often apparent.

[16] A study of red-shouldered hawk home range and habitat use in southern California found average home range of 1.2 square kilometres (0.46 sq mi) and showed fair adaptability to human-altered landscapes, which is important as riparian forest habitat has diminished by 98% from 1850 to 1977 in California's Central Valley.

In the east, they live in bottomland hardwood stands, flooded deciduous swamps, and upland mixed deciduous–conifer forests.

They are not exclusively birds of deep forest, though; one can find red-shouldered hawks in some suburban areas where houses or other buildings are mixed into woodlands.

Unusual food items recorded for the species have included nocturnal animals such as eastern screech owls and flying squirrels and road-killed deer.

While courting or defending territories, the distinctive, screaming kee-aah call (usually repeated three to four times) of this bird is heard.

Males may also perform the "sky-dance" by soaring high in the air, and then making a series of steep dives, each followed by a wide spiral and rapid ascent.

The breeding pair builds a stick nest (sometimes including shredded bark, leaves and green sprigs) in a major fork of a large tree.

[25] Humans, intentionally or unintentionally, are a threat to red-shouldered hawks, including hunting, collision with electric wires, road accidents and logging.

Raccoons, martens, fishers and large arboreal snakes can prey on eggs, hatchlings, fledglings and occasionally incubating and brooding adults.

Non-nesting adults, being a fairly large and powerful predator, have fewer natural predators, but (both during and after the breeding season, as well as among nestlings) they may be preyed on by other red-shouldered hawks, great horned owls, red-tailed hawks, barred owls, american goshawks, peregrine falcons, prairie falcons, and bald and golden eagles.

Despite their highly similar diet and habitat preferences, it has been found that red-shouldered hawks can nest within 48 m (157 ft) of a barred owl without interspecies conflict.

The changing of habitats has led to a general population increase of the red-tailed hawk, an occasional predator of its cousin.

Additionally affecting the red-shouldered hawk was the greater availability of firearms in the early 1900s, leading to unchecked hunting of this and all other raptor species until conservation laws took effect in the latter half of the 20th century.

Local forest regrowth and the ban of hunting has allowed red-shouldered hawk populations to become more stable again and the species is not currently considered conservation dependent.

In Florida, the red-shouldered hawk is perhaps the most commonly seen and heard raptor species (outside of abundant black and turkey vultures).

[30] However, human activity, including logging, poisoning from insecticides and industrial pollutants, continue to loom as threats to the species.

Before its use was outlawed in the United States, red-shouldered hawks and other raptors suffered from exposure to DDT, a pesticide.