Incubating red-shouldered hawk adults, nestlings and eggs are vulnerable to predation by great-horned owls and raccoons. Non-incubating adults are not usually vulnerable to predation.
Known Predators:
Red-shouldered hawks are large, broad-winged hawks with a relatively long tails and heavy bodies. They show reverse sexual size dimorphism, meaning that females are larger than males. Female red-shouldered hawks average 700 g and 48 to 61 cm in length whereas males average 550 g and 43 to 58 cm in length. Adults have a wingspan of 92 to 107 cm (average 100 cm). Adult red-shouldered hawks have a brown head, a dark brown back and reddish underparts with dark brown streaks. Juveniles appear similar to adults, but have creamy underparts with dark brown spots and streaks. Both adults and juveniles have reddish lesser secondary upper wing coverts, which give the impression of red shoulders, giving this species its name. The tail of the both immature and mature red-shouldered hawks is dark brown with white bands.
Five subspecies of Buteo lineatus are recognized. These subspecies are separated based on geography and physical characteristics. The head and breast markings of the Florida subspecies, Buteo lineatus extimus and Buteo lineatus alleni, are slightly paler than other Red-shouldered hawks. The California subspecies, Buteo lineatus elegans, and the Texas subspecies, Buteo lineatus texanus, however, have vibrant, deep red markings on the lesser secondary upperwing coverts, underwing coverts and breast.
Range mass: 550 to 700 g.
Range length: 43 to 61 cm.
Range wingspan: 92 to 107 cm.
Average wingspan: 100 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic
Sexual Dimorphism: female larger
Average basal metabolic rate: 2.11 W.
Red-shouldered hawks use physical displays, such as courtship flights, and vocalizations to communicate. Biologists recognize seven different calls given by red-shouldered hawk adults. The most common call is "kee-aah". This call is used to announce that a territory is occupied, and when the birds are alarmed.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Prior to 1900, this species was one of the most common hawks in eastern North America. Population densities declined substantially through most of the 20th century, probably due to hunting and destruction of wet hardwood forest habitat. Poisoning from insecticides and industrial pollutants and loss of habitat are major threats to this species. Disturbance of nesting pairs by human activity such as logging and climbing of nest trees also presents a serious threat to some populations.
This species is listed as threatened or endangered in several U.S. states, including Michigan. It is protected in the U.S. under the Migratory Bird Treaty Act. This species is also listed under CITES Appendix II, limiting international trade of individuals or body parts.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: appendix ii
State of Michigan List: threatened
IUCN Red List of Threatened Species: least concern
Though red-shouldered hawks primarily eat rodents and other small mammals, they occasionally attack poultry, making them a nuisance to farmers. Many of these hawks are killed annually by farmers for this reason. The nickname "hen hawk" for red-shouldered hawks comes from their tendency to take advantage of poultry farms.
Negative Impacts: crop pest
Red-shouldered hawks prey on rodents that are agricultural pests.
Positive Impacts: controls pest population
Red-shouldered hawks compete with other large birds, including golden eagles, prairie falcons, red-tailed hawks, barred owls and great-horned owls for territories. They provide food for their predators; primarily great horned owls and raccoons. They also host at least one blood parasite (Leucocytozoa) and several external parasites.
The diet of red-shouldered hawks consists primarily of small mammals, the largest of these being rabbits and squirrels. Other food items include reptiles and amphibians, such as snakes, toads, frogs and lizards, small birds and large insects. Crayfish are important prey for red-shouldered hawks in some regions.
Red-shouldered hawks search for prey while perched on a treetop or soaring over woodlands. When they sight prey, they kill it by dropping directly onto it from the air. They may cache food near their nest for later consumption.
Red-shouldered hawks use sight and hearing to hunt successfully. They do not hunt by smell. Some key characteristics that make red-shouldered hawks especially well-adapted to hunting are sharp eyesight and broad wings. The shape and structure of red-shouldered hawks’ wings allow them to soar effortlessly for extended periods of time searching for prey. The hawks’ large eyes are situated to look forward. Although this means that the birds must turn their heads in order to keep prey in view, the orientation of their eyes affords them excellent depth perception. The high concentrations of light-sensitive cone cells in red-shouldered hawks’ eyes also provide good resolving power and very sharp vision.
Animal Foods: birds; mammals; amphibians; reptiles; insects; aquatic crustaceans
Foraging Behavior: stores or caches food
Primary Diet: carnivore (Eats terrestrial vertebrates)
Red-shouldered hawks are found in the Nearctic region. They breed throughout the eastern and northeast United States into southern Canada, and west of the Sierra Nevada in California. Populations of red-shouldered hawks in the eastern U.S. and California are resident. Populations that breed in the northeast U.S. and southern Canada migrate to northern Mexico for the winter.
Biogeographic Regions: nearctic (Native )
Red-shouldered hawks usually inhabit mature deciduous or mixed deciduous-conifer forests and swamps. They build their nests 6 to 15 meters (20 to 60 feet) above the ground in the branches of deciduous trees in wet woodland areas. They prefer to have dead trees nearby, where they can perch and enjoy an unobstructed view of the forest floor.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: forest
Wetlands: swamp
Wild red-shouldered hawks live an average of 25.6 months. The oldest known red-shouldered hawk lived 19 years and 11 months.
Range lifespan
Status: wild: 20 (high) years.
Average lifespan
Status: wild: 25.6 months.
Average lifespan
Status: wild: 239 months.
Red-shouldered hawks are monogamous and territorial. Courtship displays occur on the breeding grounds, and involve soaring together in broad circles while calling, or soaring and diving toward one another. 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. These courtship flights usually occur in late morning and early afternoon.
Mating System: monogamous
Red-shouldered hawks breed once per year between April and July, with peak activity occurring between early April and mid June. They often use the same nest from year to year, refurbishing it each spring. Both the male and female build or refurbish the nest, which is large and deep, constructed from sticks, twigs, shredded bark, leaves and green sprigs.
The female lays 3 to 4 white eggs with brown or lavender blotches over the course of 2 to 3 days. Incubation begins when the first or second egg is laid, and lasts for 33 days. Hatching is asynchronous, with up to 7 days between the first and last chick. The nestlings are altricial, and are brooded nearly constantly by the female for at least a week. The male brings food to the nest for the female and nestlings during the nestling stage, which lasts approximately 6 weeks. Chicks begin to leave the nest at 6 weeks, but are fed by the parents for another 8 to 10 weeks. Chicks become independent of the parents at 17 to 19 weeks old. After becoming independent, they may still roost in or near the nest at night. Red-shouldered hawks begin breeding when they are 1 year old or older.
Breeding interval: Red-shouldered hawks breed once yearly.
Breeding season: Red-shouldered hawks breed between April and July, with peak activity occurring between early April and mid June.
Range eggs per season: 3 to 4.
Average time to hatching: 33 days.
Average fledging age: 6 weeks.
Range time to independence: 17 to 19 weeks.
Range age at sexual or reproductive maturity (female): 1 (low) years.
Range age at sexual or reproductive maturity (male): 1 (low) years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average time to hatching: 33 days.
Average eggs per season: 3.
Male and female red-shouldered hawks both protect the nest and incubate the eggs. The female broods the chicks during the nestling stage while the male does most of the hunting for the female and the chicks. Both parents feed the young during the nestling and fledgling stages.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female); post-independence association with parents
A relatively large (17-24 inches) hawk, the Red-shouldered Hawk takes its name from the large rust-colored shoulder patches visible from above or while perching. This species may also be identified by its brown back, barred white-and-black wings, and broad black tail banded with white. A pale form, with washed-out plumage on the chest, back, and head, occurs in south Florida. Like most species of raptors, females are larger than males. The Red-shouldered Hawk primarily breeds in the eastern United States and southeastern Canada, withdrawing from northern portions of its range and expanding south into northern Mexico in winter. Unusually for a North American hawk, the Red-shouldered Hawk has another population, separated from the main population by thousands of miles, that is a permanent resident along the Pacific coast of California. Eastern Red-Shouldered Hawks inhabit mature forests with deciduous or mixed deciduous and evergreen trees. Western populations also inhabit these habitat types, but are also likely to be found in human-altered environments near woods. Red-shouldered Hawks primarily eat small vertebrates, including small mammals, amphibians, and occasionally small songbirds and doves. Red-shouldered Hawks may be most easily observed while hunting, when they drop down from high perches to capture terrestrial prey with their talons. This species may also be observed perching, although this hawk’s coloration and the dense vegetation of its preferred habitat help to provide camouflage. Red-shouldered Hawks are most active during the day.
A relatively large (17-24 inches) hawk, the Red-shouldered Hawk takes its name from the large rust-colored shoulder patches visible from above or while perching. This species may also be identified by its brown back, barred white-and-black wings, and broad black tail banded with white. A pale form, with washed-out plumage on the chest, back, and head, occurs in south Florida. Like most species of raptors, females are larger than males. The Red-shouldered Hawk primarily breeds in the eastern United States and southeastern Canada, withdrawing from northern portions of its range and expanding south into northern Mexico in winter. Unusually for a North American hawk, the Red-shouldered Hawk has another population, separated from the main population by thousands of miles, that is a permanent resident along the Pacific coast of California. Eastern Red-Shouldered Hawks inhabit mature forests with deciduous or mixed deciduous and evergreen trees. Western populations also inhabit these habitat types, but are also likely to be found in human-altered environments near woods. Red-shouldered Hawks primarily eat small vertebrates, including small mammals, amphibians, and occasionally small songbirds and doves. Red-shouldered Hawks may be most easily observed while hunting, when they drop down from high perches to capture terrestrial prey with their talons. This species may also be observed perching, although this hawk’s coloration and the dense vegetation of its preferred habitat help to provide camouflage. Red-shouldered Hawks are most active during the day.
there are four subspecies of buteo lineatus :B.L.ALLENI,B.L.ELEGANS,B.L.EXTIMUS,B.L.TEXANUS.
The red-shouldered hawk (Buteo lineatus) is a medium-sized buteo. Its breeding range spans eastern North America and along the coast of California and northern to northeastern-central Mexico. It is a permanent resident throughout most of its range, though northern birds do migrate, mostly to central Mexico. The main conservation threat to the widespread species is deforestation.
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. He placed it with the eagles, hawks and relatives in the genus Falco and coined the binomial name Falco lineatus.[2] Gmelin based his account on the "barred-breasted buzzard" of John Latham and the "red shouldered falcon" of Thomas Pennant. Latham had described a preserved specimen from North America in the Leverian collection while Pennant's specimen formed part of the collection of Anna Blackburne and had come from Long Island.[3][4][5] The red-shouldered hawk is now placed with 27 other species in the genus Buteo that was introduced in 1799 by Bernard Germain de Lacépède.[6][7] The genus name Buteo is Latin for a "buzzard". The specific epithet lineatus is Latin meaning "marked with lines" or "lined".[8]
Five subspecies are recognised:[7]
Males are 38 to 58 cm (15 to 23 in) long and weigh on average 550 g (1.21 lb). Females are slightly larger at 47 to 61 cm (19 to 24 in) in length and a mean weight of 700 g (1.5 lb). The wingspan can range from 90 to 127 cm (35 to 50 in).[9][10][11][12] Adult birds can vary in mass from 460 to 930 g (1.01 to 2.05 lb). Among standard measurements, the wing bone is 28–35 cm (11–14 in) long, the tail is 16–24 cm (6.3–9.4 in) long and the tarsus is 7.5–9 cm (3.0–3.5 in).[13] 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. 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. This bird is sometimes also confused with the widespread red-tailed hawk. That species is larger and bulkier, with more even-sized, broad wings, and is paler underneath, with a reddish tail often apparent. The red-tail is also more likely to soar steadily, with wings in a slight dihedral.
An eastern population ranges west through southern Canada from southern New Brunswick and Ontario to the eastern edge of the U.S. Great Plains, south to Florida, the Gulf Coast, and eastern Mexico. Only northernmost populations are migratory. A western population breeds west of the Sierra Nevada from northern California to northern Baja California, and has recently expanded into Oregon and Arizona, and east of the Sierra Nevada in California and southern Nevada.
Eastern populations winter from southern Wisconsin, Oklahoma, Ohio, and southern New England south to the Gulf Coast, occasionally throughout breeding range. In winter, they are reported south to Jalisco and Veracruz, Mexico. Western populations are largely nonmigratory. Throughout its winter range, this species avoids higher elevations.
Eastern birds occasionally wander west (e.g., Colorado, Kansas, West Texas, Manitoba, North Dakota) in migration; western birds have strayed east to Arizona, Nevada, Idaho, and Utah, and north to Washington.[14]
In the east, individuals from the northern half of the species’ range are migratory. In the west, most populations are local. Red-shouldered hawks are short- to moderate-distance migrants, with most individuals traveling distances between 300 and 1,500 km each way. The species follows leading lines, migrating along inland ridges and coastlines. Larger numbers of red-shouldered hawks are counted at coastal watch sites than at inland sites. Juveniles often precede adults on migration in autumn, whereas adults precede juveniles in the spring. Red-shouldered hawks typically migrate alone, although they sometimes form small flocks of three or more birds. The species usually avoids crossing large bodies of water. While migrating, red-shouldered hawks are observed in soaring, gliding, and flapping flight.[15]
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.[16]
Red-shouldered hawks are forest raptors. In the east, they live in bottomland hardwood stands, flooded deciduous swamps, and upland mixed deciduous–conifer forests. They tend to live in stands with an open subcanopy, which makes hunting easier. 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. In the west, they live in riparian and oak woodlands, and also in eucalyptus groves and some residential areas.[12]
Red-shouldered hawks search for prey while perched on a treetop or soaring over woodlands. When they sight prey, they kill it by dropping directly onto it from the air. They may cache food near their nest for later consumption.[9] When in clearings, they sometimes fly high and then drop to surprise prey. Red-shouldered hawks, like most raptors, have very good vision and reasonably good sense of hearing, with talons capable of killing animals as big as their own size. Small mammals are typically the most common prey, especially rodents. Voles, gophers, mice, moles and chipmunks may locally be favored based on abundance. Slightly larger mammals, such as rabbits and tree squirrels, are also occasionally preyed on. Other prey can include amphibians, reptiles (especially small snakes), birds, fish,[17] and large insects. They will attack birds up to the size of a ruffed grouse or ring-necked pheasant. Steller's jays and blue jays, both of which being potential prey species, sometimes habitually imitate the call of the red-shouldered hawk and are known to be difficult to distinguish on voice alone.[18] During winters, red-shouldered hawks sometimes habituate to preying on birds commonly found at bird feeders. In some areas where they are common, crayfish can be important prey for this species. Unusual food items recorded for the species have included nocturnal animals such as eastern screech owls and flying squirrels and road-killed deer.[19]
The breeding habitats of the red-shouldered hawk are deciduous and mixed wooded areas, often near water. They have been known to nest near residential areas and open water but this is much less common.[20] Red-shouldered hawks select sites with greater tree species richness for nesting.[21] Like almost all raptors, the red-shouldered hawk is monogamous and territorial. While courting or defending territories, the distinctive, screaming kee-aah call (usually repeated three to four times) of this bird is heard. Courtship displays occur on the breeding grounds, and involve soaring together in broad circles while calling, or soaring and diving toward one another. 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. These courtship flights usually occur in late morning and early afternoon.
Red-shouldered hawks' mating season is between April and July, with activity usually peaking between April and mid-June. The breeding pair builds a stick nest (sometimes including shredded bark, leaves and green sprigs) in a major fork of a large tree. They often use the same nest year after year, refurbishing it annually with sticks in the spring. The clutch size is typically three to four eggs. The blotchy-marked eggs, often brown to lavender in color, measure on average 54.5 mm × 43 mm (2.15 in × 1.69 in). The incubation period can range from 28 to 33 days. Hatching is asynchronous, with the first chick hatching up to a week before the last. The hatchlings, which weigh 35 g (1.2 oz) at first, are brooded almost constantly by the female for up to 40 days. Pairs that nest earlier in the breeding season tend to lay greater numbers of eggs and have higher productivity from those eggs.[22] The male more often captures food but will also incubate and brood occasionally. 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. They may continue to roost near the nest site until the following breeding season. Breeding maturity is usually attained at 1 or 2 years of age.
Although they have lived as long as within a month of 20 years old, few live half that long and only around half survive their first year. Each year overall nesting success can be lower than 30 percent.[23] Early mortality can be due to natural causes, relating to harsh weather conditions, or more often starvation. Young hawks are often parasitized by species such as Trichomonas gallinae, Protocalliphora avium, and various species of blood parasites.[24] Humans, intentionally or unintentionally, are a threat to red-shouldered hawks, including hunting, collision with electric wires, road accidents and logging. A further common cause of mortality is natural predation. 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, northern goshawks, peregrine falcons, prairie falcons, and bald and golden eagles. In western New York, the main cause of nest failure was stated to be great horned owl predation.[25] Many of the same predators sometimes compete over territory and food with this species. 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.[26] In Florida, red-shouldered hawks sometimes collaborate and peaceably coexist with American crows (usually an enemy to all other birds because of their egg-hunting habits) so they cooperatively mob mutual predators, mainly great horned owls and red-tailed hawks.[27]
Red-shouldered hawks have hybridized with gray hawks (Buteo plagiatus), red-tailed hawks (Buteo jamaicensis) and common black hawks (Buteogallus anthracinus).[28]
Prior to 1900, the red-shouldered hawk was one of the most common North American raptors. Population densities have decreased precipitously due to the clearing of mature forests (principally the wet hardwood forest they prefer) since that time. 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).[29] 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. The DDT would cause their eggs to have thin, breakable shells, reducing their ability to reproduce. Accidental encounters with power lines and automobiles also take a toll on hawks. In spite of these dangers, habitat loss remains the biggest threat to red-shouldered hawks.[11]
John James Audubon illustrated the red-shouldered hawk in his book Ornithological Biographies.
Lighthouse Beach Park, Sanibel, Florida
Red-shouldered hawk, scanning, East Hartford, Connecticut
Red-shouldered hawk with a kill
Dunwoody, Georgia
Cloisters City Park, Morro Bay, California
Kanapaha Botanical Gardens, Gainesville, Florida
Palm Beach County, Florida
Avian Reconditioning Center, Florida
Placer County, California
Suburban Indianapolis, Indiana
The red-shouldered hawk (Buteo lineatus) is a medium-sized buteo. Its breeding range spans eastern North America and along the coast of California and northern to northeastern-central Mexico. It is a permanent resident throughout most of its range, though northern birds do migrate, mostly to central Mexico. The main conservation threat to the widespread species is deforestation.
