Red-tailed hawks are native only to the Nearctic region. They are found throughout the United States and Canada, and into Mexico and Central America. Many birds are year round occupants although the birds of the far north migrate south during the fall to escape the harsh winter.

Biogeographic Regions: nearctic (Native )

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: western and central Alaska, central Yukon, western Mackenzie, northern Saskatchewan, northern Manitoba, central Ontario, southern Quebec, New Brunswick, Prince Edward Island, and Nova Scotia south to southeastern Alaska, Baja California, Sonora, Chihuahua, Nuevo Leon, southern Texas, Gulf Coast, and Florida, and highlands of Middle America to Costa Rica and western Panama (east to Canal Zone); in Tres Marias and Socorro islands off western Mexico; and in northern Bahamas (Grand Bahama, Abaco, Andros), Greater Antilles, and northern Lesser Antilles (Saba south to Nevis) (AOU 1983). WINTERS: southern Canada south through remainder of breeding range, also in lowlands of Central America. In the U.S., most abundant in winter in California-western Nevada and in the farming and ranching region of the central U.S. (Root 1988). Accidental in England and Bermuda (AOU 1983).

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Red-tailed hawks are 48 to 65 centimeters in length. Their wingspan is approximately 4 feet, or 122 centimeters. Females and males are similar in appearance, but females are 25% larger than males. This kind of sexual dimorphism, where females are larger than males, is common in birds of prey. Mass is reported from 795 to 1224 grams, with mass varying by sex, season, and geographically. Red-tailed hawks range from light auburn to deep brown in color. Their underbelly is lighter than the rest of the body, with a dark band across it. The cere (the soft skin at the base of the beak), the legs and the feet are all yellow. The tail is brownish-red, and it is this trait that gives red-tailed hawks their name.

Immature red-tailed hawks look similar to adults, but... Immatures also have yellowish-gray eyes that become dark brown as adults.

There are at least 14 subspecies of Buteo jamaicensis. These subspecies are separated based differences in their color and differences in where they breed and spend the winter.

Range mass: 795 to 1224 g.

Range length: 45 to 65 cm.

Average wingspan: 122 cm.

Other Physical Features: endothermic ; bilateral symmetry ; polymorphic

Sexual Dimorphism: female larger

Length: 56 cm

Weight: 1224 grams

• Terrestrial

Red-tailed hawks inhabit a wide range of habitats over a wide range of altitudes. These habitats are typically open areas with scattered, elevated perches, and include scrub desert, plains and montane grasslands, agricultural fields, pastures, urban parks, patchy coniferous and deciduous woodlands, and tropical rainforests. Red-tailed hawks prefer to build their nests at the edge of forests, in wooded fence rows, or in large trees surrounded by open areas.

Habitat Regions: temperate ; tropical ; terrestrial

Terrestrial Biomes: desert or dune ; savanna or grassland ; forest ; rainforest ; scrub forest

Other Habitat Features: urban ; suburban ; agricultural ; riparian

Comments: Wide variety of open woodland and open country with scattered trees, rarely in denser forest (AOU 1983), but nests in forest and takes prey from forest canopy in Puerto Rico (Recher and Recher 1966, Santana 1988). Elevated perches are important element of habitat.

Nests in trees to 37 m above ground, frequently high in tallest tree near edge of woods; also, in treeless country, in top of shrub, cactus, or on cliff. Often returns to same nesting area in successive years.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Northern populations mainly migratory (some breeders resident on or near territories all year), generally arrive in northern breeding areas in March and April (yearlings may still be migrating as late as May and June), depart by September-October (Bent 1937), may continue southward movement into December. Migrations may be influenced by food supply. Most migrants from north migrate no farther south than northern Mexico (Palmer 1988).

Red-tailed hawks feed on a wide variety of prey, using their powerful claws as weapons. Eighty to eighty-five percent of their diet consists of small rodents. Mammals as large as eastern cottontail rabbits may also taken. Reptiles and other birds make up the rest of the diet. Male red-winged blackbirds are common prey because they are so visible when guarding their nests. Red-tailed hawks do most of their hunting from a perch. They are not known to store food.

Animal Foods: birds; mammals; reptiles

Primary Diet: carnivore (Eats terrestrial vertebrates)

Comments: Opportunistic. Rodents, lagomorphs, birds, and reptiles common in diet but also eats various other vertebrates and sometimes invertebrates as available. Among several hunting methods, perch-and-wait most common and yields greatest success (Palmer 1988). Also perches and hunts along highways.

Red-tailed hawks play an important role in local ecosystems by helping to control the populations of small mammals, including rodents and rabbits. They also provide habitat for some small bird species, including house sparrows, that live in active red-tailed hawk nests.

Red-tailed hawks have antagonistic relationships with many bird species. Some smaller bird species mob hawks. Red-tailed hawks also steal prey and have prey stolen by other large birds, including golden eagles, bald eagles and ferruginous hawks.

Ecosystem Impact: creates habitat

Commensal/Parasitic Species:

• house sparrow

Adult red-tailed hawks are large formidable birds, and have few predators. Most predation on this species occurs to eggs and nestlings. Great horned owls are known predators of red-tailed hawk nestlings. Corvids are known predators of eggs and nestlings.

Known Predators:

• great horned owls (Bubo virginianus)
• crows (Corvus)

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

10,000 to >1,000,000 individuals

Breeding density (pairs /sq. km) varies from 0.03 (Utah) to 0.78 (California); mostly less than 0.025 (but 0.2-0.6 pairs/sq. km in different habitats in Puerto) (Santana 1988, Rothfels and Lein 1983). In Puerto Rico, remains paired and defends territory throughout the year (Santana 1988). Also territorial in winter in at least some parts of the U.S. In a largely sedentary population in Wisconsin, mean seasonal home ranges varied as follows: fall male 390 ha (n=1), female 123 ha (n=2); winter male 157 ha (n=3), female 167 ha (n=6); spring male 163 ha (n=2), female 85 ha (n=6); summer male 117 ha (n=1), female 117 ha (n=5) (Petersen 1979). Most forage within 3 kilometers of the nest (Kochert 1986). See Palmer (1988) for discussion of interactions with other hawks and Great Horned Owl.

Adult red-tailed hawks make what is called a horse scream, "kee-eeee-arrr." It is often described as sounding like a steam whistle. The length and pitch of this call varies with the age, gender, and geographic region of the individual red-tailed hawk.

Young red-tailed hawks communicate with their parents by making soft, low "peep"-ing sounds. As they get older, they sounds they make deepen in tone, and are usually sounds of hunger.

Red-tailed hawks also communicate through body language. In an aggressive posture, the body and head of the  red-tailed hawk are held upright and its feathers are standing up. In submission, the hawk's head is lower to the ground and the feathers are smooth. Red-tailed hawks also display many aerial behaviors. In the talon-drop, during courtship, they swoop down trying to touch one another with their talons. Undulating-flight is an up and down movement that is mainly used in territorial display. Finally, in the dive-display the bird performs a steep dive. This is also a territorial display.

Red-tailed hawks have extraordinarily keen vision, which allows them to detect prey movements at great distances.

Communication Channels: visual ; acoustic

Comments: Rain and fog reduce flying activity and foraging time in forest birds in Puerto Rico (Santana 1988).

Red-tailed hawks are relatively long-lived birds. While many of these birds die young (most live less than two years), those that survive the first few years can live for many years. The oldest known wild red-tailed hawk lived to at least 21.5 years old. In captivity, red-tailed hawks have lived for at least 29.5 years.

Range lifespan

Status: wild: 29.5 (high) years.

Range lifespan

Status: captivity: 29.5 (high) years.

Average lifespan

Status: wild: 346 months.

Red-tailed hawks usually begin breeding when they are three years old. They are monogamous, and mate with the same individual for many years. In fact, red-tailed hawks usually only change mates when their original mate dies. During courtship, the male and female soar together in circles, with flights lasting 10 minutes or more. Mating usually takes place following these flights. The male and female land on a perch and preen each other. The female then tilts forward, allowing the male to mount her. Copulation lasts 5 to 10 seconds.

Mating System: monogamous

Red-tailed hawk nests are usually 28 to 38 inches in diameter. They are sometimes used for several years, and can be up to 3 feet tall. The male and female both construct the nest in a tall tree, 4 to 21 meters above the ground. Where trees are scarce, they are sometimes built on cliff ledges or artificial structures such as on buildings. The nests are constructed of twigs and lined with bark, pine needles, corn cobs, husks, stalks, aspen catkins and other soft plant matter. Fresh bark, twigs, and pine needles are deposited into the nest throughout the breeding season to keep the nest clean. Owls compete with the red-tailed hawks for nest sites. Each species is known to kill the young and destroy the eggs of the other in an attempt at taking a nest site.

The female lays 1 to 5 eggs around the first week of April. The eggs are laid approximately every other day and are incubated for 28 to 35 days. Both parents incubate the eggs. Males may spend less time incubating than females, but bring food to the female while she is on the nest. The young hatch over the course of 2 to 4 days, and are altricial at hatching. During the nestling stage, the female broods the young, and the male provides most of the food to the female and the chicks. The female feeds the nestlings by tearing the food into small pieces. The chicks begin to leave the nest after 42 to 46 days. The fledgling period lasts up to 10 weeks, during which the chicks learn to fly and hunt.

Breeding interval: Red-tailed hawks breed each spring.

Breeding season: Breeding occurs in the spring.

Range eggs per season: 1 to 5.

Range time to hatching: 28 to 35 days.

Average time to hatching: 30 days.

Range fledging age: 42 to 46 days.

Range time to independence: 10 (high) weeks.

Average age at sexual or reproductive maturity (female): 3 years.

Average age at sexual or reproductive maturity (male): 3 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization

Average eggs per season: 3.

Average age at sexual or reproductive maturity (male)

Sex: male: 730 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 730 days.

Both parents incubate the eggs. Males may spend less time incubating than females, but bring food to the female while she is on the nest. The newly hatched chicks are altricial (helpless). During the nestling stage, the female broods the young, and the male provides most of the food to the female and the chicks. The female feeds the nestlings by tearing the food into small pieces. The chicks begin to leave the nest after 42 to 46 days. After they leave the nest, young red-tailed hawks usually stay in one place, close to their parents. They begin to fly about 3 weeks after they first begin to leave the nest, and begin to catch their own food 6 to 7 weeks after that. They become completely independent from their parents by about 10 weeks after fledging, at about 112 to 116 days old.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)

Clutch size commonly is 2-3. Incubation lasts about 34 days per egg, mostly by female. Young are tended by both parents, may leave nest at about 4 weeks, fly at about 6.5-7 weeks, depend on parents for food for at least a few weeks after fledging. If clutch lost, renests usually in another nest a few weeks later. Successful reproduction usually does not occur before age 2 years. Pair bond typically lifelong, at least in nonmigratory populations and probably in migrants as well.

Red-tailed hawks have extended their geographic range over the last 100 years. This expansion is most likely the result of increasing habitat of patchy woodland and open areas. As these areas become filled in with forest or more completely opened up, the amount of habitat for red-tailed hawks is expected to decline.

Currently, the greatest threats to red-tailed hawk populations are shootings, collisions with automobiles, and human interference with nesting activities. Lead poisoning from eating food items that contain lead shot also kills a number of red-tailed hawks each year.

Red-tailed hawks are protected under the U.S. Migratory Bird Act and CITES Appendix II.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: appendix ii

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5B - Secure

United States

Rounded National Status Rank: N5B,N5N : N5B: Secure - Breeding, N5N: Secure - Nonbreeding

Rounded Global Status Rank: G5 - Secure

Reasons: Large range in North and Central America; increasing or stable populations in most areas of the U.S.and Canada; no significant threats on a global scale.

Global Short Term Trend: Increase of 10 to >25%

Comments: Breeding Bird Survey data indicate a significant population increase in North America between 1966 and 1993 (Droege and Sauer 1990, Peterjohn et al. 1994, Price et al. 1995). May be decreasing in the northeastern U.S. (Bednarz et al. 1990). However, Titus and Fuller (1990) found no consistent trend in migration counts in northeastern North America, 1972-1987. Decreases in migration counts may in part reflect a larger proportion of birds wintering in the north (Kirk et al. 1995). See Walter (1990) for an account of the small but viable population of subspecies SOCORROENSIS on Soccoro Island, Mexico. See Kirk (1995 COSEWIC report) for information on status in Canada.

There are no known negative effects of red-tailed hawks on humans.

Red-tailed hawks help farmers by eating mice, moles and other rodents that disturb their crops.

Positive Impacts: controls pest population

Comments: Includes B. harlani, formerly regarded as a separate species (AOU 1998). See Mindell (1983) for information on the taxonomic status of harlani.

The phylogenetic status of the nominal subspecies needs to be evaluated with genetic techniques; do the geographic color variations represent distinct evolutionary lineages?