Red-tailed hawks, especially those in the West, have a very variable plumage, including reddish brown and dark phases. Their wings are long and broad and their tails short and wide. Most have light colored breasts with dark streaks making a mottled "belly-band". Most of them have dark brown heads. Their underwings are mottled light and dark. They all have a dark band on the outside edge of the inner underwings, called the "patagial" markings. On most adults the upper side of their tail is deep rufous. Lighter birds often feature a faint white "V" as part of their back-feathers, as seen when they are perching. Juveniles don't have a red tail.
Red-tailed hawk is one of the most common hawk in North America. They are found all over the continent, as well as in Central America, and in the Caribbean. Many birds remain in their areas all year, but birds in the far north migrate during autumn to avoid the harsh winter. These hawks occupy a vast range of habitats within a wide range of altitudes, including scrub desert, montane grasslands, plains, agricultural fields, pastures, patchy deciduous and coniferous woodlands, coastal regions, urban parks and tropical rainforests.
Red-tailed hawks are diurnal. They will soar above their territory, usually on clear days, keeping a lookout for intruders. They are mostly solitary but are social during breeding season and migration. These hawks prefer to form their nests in wooded fence rows at the edge of forests, or in large trees within open areas. Pairs will stay together for years within the same territory. They are very territorial, defending territories that range from 0.85 to 3.9 square kilometers, based on the availability of food, perches, and sites for nests. The female is more aggressive than the male around the nest, while the male is more aggressive with regard to the territory boundaries.
Red-tailed hawks are carnivores, their diet varying with the location and the season. They eat small mammals including voles, rats, ground squirrels and rabbits, birds, and reptiles, especially snakes, bats, frogs, toads, and insects. They may feed on carrion.
Red-tailed hawks usually mate at 3 years old. They are monogamous, and stay with the same partner for many years. They soar together in circles during courtship, their flights lasting 10 minutes and more. Mating usually occurs following these flights. Breeding and nest building start in early spring, usually March, continuing through May. Usually 1-5 eggs are laid. Incubation lasts 28-32 days, carried out almost exclusively by the female. The male supplies most of the food for the mother and the chicks during the nestling stage. The chicks can leave the nest in 42 to 46 days. 10 weeks is the fledgling period, during which chicks learn to hunt and fly.
While fairly numerous in North America, these hawks, like all wildlife, are threatened by hunters, loss of habitat, pollution, and cars. Red-tailed hawks control populations of rodents and grasshoppers and have protection under the U.S. Migratory Bird Act.
According to AllAboutBirds, the estimated global breeding population is 2.3 million. 75% spend part of each year in the U.S., 21% in Mexico and 24% in Canada. The ICUN classifies the Red-tailed hawk as "Least Concern", with an increasing population trend.
Red-tailed hawks have an important part to play in local ecosystems by controlling populations of small mammals, such as rodents and rabbits. They benefit farmers by eating moles, mice and other rodents that threaten crops. They also provide habitat for several small bird species, such as house sparrows that live alongside hawks in their nests.