Red-tailed hawks are considered partial migrants, as in about the northern third of their distribution, which is most of their range in Canada and Alaska, they almost entirely vacate their breeding grounds. In coastal areas of the north, however, such as in the Pacific Northwest  to southern Alaska and in Nova Scotia on the Atlantic, red-tailed hawks do not usually migrate. More or less, any area where snow cover is nearly continuous during the winter shows an extended absence of most red-tailed hawks, so some areas as far south as Montana may show strong seasonal vacancies of red-tails. In southern Michigan, immature red-tailed hawks tended to remain in winter only when voles were abundant. During relatively long,  harsh winters in Michigan, many more young ones were reported in northeastern Mexico. To the opposite extreme, hawks residing as far north as Fairbanks, Alaska, may persevere through the winter on their home territory, as was recorded with one male over three consecutive years. Birds of any age tend to be territorial during winter but may shift ranges whenever food requirements demand it. Wintering birds tend to perch on inconspicuous tree perches, seeking shelter especially if they have a full crop or are in the midst of poor or overly windy weather. Adult wintering red-tails tend to perch more prominently than immatures do, which select lower or more secluded perches. Immatures are often missed in winter bird counts, unless they are being displaced by dominant adults. Generally, though, immatures can seem to recognize that they are less likely to be attacked by adults during winter and can perch surprisingly close to them. Age is the most significant consideration of wintering hawks' hierarchy, but size does factor in, as larger immatures (presumably usually females) are less likely to displaced than smaller ones. Dark adult red-tailed hawks appear to be harder to locate when perched than other red-tails. In Oklahoma, for example, wintering adult Harlan's hawks were rarely engaged in fights or chased by other red-tails. These hawks tended to gather in regional pockets and frequently the same ones occurred year-to-year. In general, migratory behavior is complex and reliant on each individual hawk's decision-making (i.e. whether prey populations are sufficient to entice the hawk to endure prolonged snow cover). During fall migration, departure may occur as soon as late September, but peak movements occur in late October and all of November in the United States, with migration ceasing after mid-December. The northernmost migrants may pass over resident red-tailed hawks in the contiguous United States, while the latter are still in the midst of brooding fledglings. Not infrequently, several autumn hawk watches in Ontario, Quebec, and the northern United States record 4,500–8,900 red-tailed hawks migrating through each fall, with records of up to 15,000 in a season at Hawk Ridge hawk watch in Duluth, Minnesota. Unlike some other Buteo spp., such as Swainson's hawks and broad-winged hawks, red-tailed hawks do not usually migrate in groups, instead passing by one-by-one, and only migrate on days when winds are favorable. Most migrants do not move past southern Mexico in late autumn, but a few North American migrants may annually move as far south as breeding red-tailed hawks happen to occur, i.e. in Central America to as far south Panama. However, a few records were reported of wintering migrant red-tails turning up in Colombia, the first records of them anywhere in South America. Spring northward movements may commence as early as late February, with peak numbers usually occurring in late March and early April. Seasonal counts may include up to 19,000 red-tails in spring at Derby Hill hawk watch, in Oswego, New York, sometimes more than 5,000 are recorded in a day there. The most northerly migratory individuals may not reach breeding grounds until June, even adults.
Immature hawks migrate later than adults in spring on average, but not, generally speaking, in autumn. In the northern Great Lakes, immatures return in late May to early June, when adults are already well into their nesting season and must find unoccupied ranges. In Alaska, adults tend to migrate before immatures in early to mid-September, to the contrary of other areas, probably as heavy snowfall begins. Yearlings that were banded in southwestern Idaho stayed for about 2 months after fledging, and then traveled long distances with a strong directional bias, with 9 of 12 recovered southeast of the study area- six of these moved south to coastal lowlands in Mexico] and as far as Guatemala, 4,205 km (2,613 mi) from their initial banding. In California, 35 hawks were banded as nestlings; 26 were recovered at less than 50 miles away, with multidirectional juvenile dispersals. Nestlings banded in Southern California sometimes actually traveled north as far as 1,190 km (740 mi) to Oregon, ranging to the opposite extreme as far as a banded bird from the Sierra Nevadas that moved 1,700 km (1,100 mi) south to Sinaloa. Nestlings banded in Green County, Wisconsin, did not travel very far comparatively by October–November, but by December, recoveries were found in states including Illinois, Iowa, Texas, Louisiana, and Florida.


The red-tailed hawk is carnivorous, and a highly opportunistic feeder. Nearly any small animal they encounter may be viewed as potential food. Their most common prey are small mammals such as rodents and lagomorphs, but they also consume birds, reptiles, fish, amphibians, and invertebrates. Prey varies considerably with regional and seasonal availability, but usually centers on rodents, accounting for up to 85% of a hawk's diet. In total, nearly 500 prey species have been recorded in their diet, almost as many as  great horned owls have been recorded as taking. When 27 North American studies are reviewed, mammals make up 65.3% of the diet by frequency, 20.9% by birds, 10.8% by reptiles, 2.8% by invertebrates, and 0.2% by amphibians and fish. The geometric mean body mass of prey taken by red-tailed hawks in North America is about 187 g (6.6 oz) based on a pair of compilation studies from across the continent, regionally varying at least from 43.4 to 361.4 g (1.53 to 12.75 oz). Staple prey (excluding invertebrates) has been claimed to weigh from 15 to 2,114 g (0.033 to 4.661 lb), ranging roughly from the size of a small mouse or lizard to the size of a black-tailed jackrabbit (Lepus californicus). The daily food requirements range from 7 to 11.2% of their own body weight, so that about three voles or the equivalent weight are required daily for a typical range adult.
The talons and feet of red-tailed hawks are relatively large for a Buteo hawk; in an average-sized adult red-tail, the "hallux-claw" or rear talon, the largest claw on all accipitrids, averages about 29.7 mm (1.17 in). In fact, the talons of red-tails in some areas averaged of similar size to those of ferruginous hawks which can be considerably heavier and notably larger than those of the only slightly lighter Swainson's hawk. This species may exert an average of about 91 kg/cm² (1,290 lbf/in²) of pressure through its feet. Owing to its morphology, red-tailed hawks generally can attack larger prey than other Buteo hawks typically can, and are capable of selecting the largest prey of up to their own size available at the time of hunting, though in all likelihood numerically most prey probably weighs on average about 20% of the hawk's own weight (as is typical of many birds of prey). Red-tailed hawks usually hunt by watching for prey activity from a high perch, also known as still hunting. Upon being spotted, prey is dropped down upon by the hawk. Red-tails often select the highest available perches within a given environment, since the greater the height they are at, the less flapping is required and the faster the downward glide they can attain toward nearby prey. If prey is closer than average, the hawk may glide at a steep downward angle with few flaps, if farther than average, it may flap a few swift wingbeats alternating with glides. Perch hunting is the most successful hunting method generally speaking for red-tailed hawks and can account for up to 83% of their daily activities (i.e. in winter). Wintering pairs may join together and aseasonally may join forces to group hunt agile prey that they may have trouble catching by themselves, such as tree squirrels. This may consist of stalking opposites sides of a tree, to surround the squirrel and almost inevitably drive the rodent to be captured by one after being flushed by the other hawk.
The most common flighted hunting method for red-tail is to cruise around 10 to 50 m (33 to 164 ft) over the ground with flap-and-glide type flight, interspersed occasionally with harrier-like quarters over the ground. This method is less successful than perch hunting, but seems relatively useful for capturing small birds and may be show the best results while hunting in hilly country. Hunting red-tailed hawks readily use trees, bushes, or rocks for concealment before making a surprise attack, even showing a partial ability to dodge among trees in an Accipiter-like fashion. Among thick stands of spruce in Alaska, a dodging hunting flight was thought to be unusually important to red-tails living in extensive areas of conifers, with hawks even coming to the ground and walking hurriedly in prey pursuit especially if the prey was large, a similar behavior to goshawks. Additional surprisingly swift aerial hunting has reported in red-tails that habitually hunt bats in Texas. Here, the bat-hunting specialists  stooped with half-closed wings, quite falcon-like, plowing through the huge stream of bats exiting their cave roosts, then zooming upwards with a bat in its talons. These hawks also flew parallel closely to the stream, then veer sharply into it and seize a bat. In the neotropics, red-tails have shown the ability to dodge amongst forest canopy whilst hunting. In Kansas, red-tailed hawks were recorded sailing to catch flying insects, a hunting method more typical of a Swainson's hawk. Alternately, they may drop to the ground to forage for insects like grasshoppers and beetles as well as other invertebrates and probably amphibians and fish (except by water in the latter cases). Hunting afoot seems to be particularly prevalent among immatures. Young red-tailed hawks in northeastern Florida were recorded often extracting earthworms from near the surface of the ground and some had a crop full of earthworms after rains. Ground hunting is also quite common on Socorro Island, where no native land mammals occur, and invertebrates are more significant to their overall diet. A red-tailed hawk was observed to incorporate an unconventional killing method, which was drowning a heron immediately after capture. One red-tailed hawk was seen to try to grab a young ground squirrel and, upon missing it, screamed loudly, which in turn caused another young squirrel to break into a run, wherein it was captured. Whether this was an intentional hunting technique needs investigation. Upon capture, smaller prey is taken to a feeding perch, which is almost always lower than a hunting perch. Among small prey, rodents are often swallowed whole, as are shrews and small snakes, while birds are plucked and beheaded. Even prey as small as chipmunks may take two or three bites to consume. Larger mammals of transportable size are at times beheaded and have part of their fur discarded, then leftovers are either stored in a tree or fall to the ground. Large prey, especially if too heavy to transport on the wing, is often dragged to a secluded spot and dismantled in various ways. If they can successfully carry what remains to a low perch, they tend to feed until full and then discard the rest.


Rodents are certainly the type of prey taken most often by frequency, but their contribution to prey biomass at nests can be regionally low, and the type, variety and importance of rodent prey can be highly variable. In total, well over 100 rodent species have turned up the diet of red-tailed hawks. Rodents of extremely varied sizes may be hunted by red-tails, with species ranging in size from the 8.2 g (0.29 oz) eastern harvest mouse (Reithrodontomys humulis) to marmots (Marmota ssp.), weighing some 3,300 g (7.3 lb) in spring, although whether they can take full grown marmots is questionable. At least some attacks on adult marmots like groundhogs (Marmota monax) are abortive. At times, the red-tailed hawk is thought of as a semi-specialized vole-catcher, but voles are a subsistence food that are more or less are taken until larger prey such as rabbits and squirrels can be captured. In an area of Michigan, immature hawks took almost entirely voles but adults were diversified feeders. Indeed, the 44.1 g (1.56 oz) meadow vole (Microtus pennsylvanicus) was the highest frequency prey species in 27 dietary studies across North America, accounting for up to 54% of the food at nests by frequency. It is quite rare for any one species to make up more than half of the food at any dietary study for red-tailed hawks. In total about 9 Microtus species are known in the overall diet, with 5 other voles and lemmings known to be included in their prey spectrum. Another well-represented species was the 27.9 g (0.98 oz) prairie vole (Microtus ochrogaster), which were the primary food, making up 26.4% of a sample of 1322, in eastern Kansas. While crepuscular in primary feeding activity, voles are known to be active both day and night, and so are reliable food for hawks than most non-squirrel rodents, which generally are nocturnal in activity. Indeed, most other microtine rodents are largely inaccessible to red-tailed hawks due to their strongly nocturnal foraging patterns, even though 24 species outside of voles and lemmings are known to be hunted. Woodrats are taken as important supplemental prey in some regions, being considerably larger than most other crictetid rodents, and some numbers of North American deermouse (Peromyscus maniculatus) may turn up. The largest representation of the latter species was contributing 11.9% of the diet in the Great Basin of Utah, making them the second best represented prey species there. Considering this limited association with nocturnal rodents, the high importance of pocket gophers in the diet of red-tailed hawks is puzzling to many biologists, as these tend to be highly nocturnal and elusive by day, rarely leaving the confines of their burrow. At least 8 species of pocket gopher are included in the prey spectrum (not to mention 5 species of pocket mice). The 110 g (3.9 oz) northern pocket gopher (Thomomys talpoides) is particularly often reported and, by frequency, even turns up as the third most often recorded prey species in 27 American dietary studies. Presumably, hunting of pocket gophers by red-tails, which has possibly never been witnessed, occurs in dim light at first dawn and last light of dusk when they luck upon a gopher out foraging.
By far, the most important prey among rodents are squirrels, as they are almost fully diurnal. All told, nearly 50 species from the squirrel family have turned up as food. In particular, where they are distributed, ground squirrels are doubly attractive as a primary food source due to their ground dwelling habits, as red-tails prefer to attack prey that is terrestrial. There are also many disadvantages to ground squirrels as prey: they can escape quickly to the security of their burrows, they tend to be highly social and they are very effective and fast in response to alarm calls, and a good deal of species enter hibernation that in the coldest climates can range up to a 6 to 9-month period (although those in warmer climates with little to no snowy weather often have brief dormancy and no true hibernation). Nonetheless, red-tailed hawks are devoted predators of ground squirrels, especially catching incautious ones as they go out foraging (which more often than not are younger animals). A multi-year study conducted on San Joaquin Experimental Range in California, seemingly still the largest food study to date done for red-tailed hawks with 4031 items examined, showed that throughout the seasons the 722 g (1.592 lb) California ground squirrel (Otospermophilus beecheyi) was the most significant prey, accounting for 60.8% of the breeding season diet and about 27.2% of the diet for hawks year-around. Because of the extremely high density of red-tailed hawks on this range, some pairs came to specialize on diverse alternate prey, which consisted variously of kangaroo rats, lizards, snakes or chipmunks. One pair apparently lessened competition by focusing on pocket gophers instead despite being near the center of ground squirrel activity. In Snake River NCA, the primary food of red-tailed hawks was the 203.5 g (7.18 oz) Townsend's ground squirrel (Urocitellus townsendii), which made up nearly 21% of the food in 382 prey items across several years despite sharp spikes and crashes of the ground squirrel population there. The same species was the main food of red-tailed hawks in southeastern Washington, making up 31.2% of 170 items. An even closer predatory relationship was reported in the Centennial valley of Montana and south-central Montana, where 45.4% of 194 prey items and 40.2% of 261 items, respectively, of the food of red-tails consisted of the 455.7 g (1.005 lb) Richardson's ground squirrel (Urocitellus richardsonii). Locally in Rochester, Alberta, Richardson's ground squirrel, estimated to average 444 g (15.7 oz), were secondary in number to unidentified small rodents but red-tails in the region killed an estimated 22–60% of the area’s ground squirrel, a large dent in the squirrel’s population. Further east, ground squirrels are not so reliably distributed, but one study in southern Wisconsin, in one of several quite different dietary studies in that state, the 172.7 g (6.09 oz) thirteen-lined ground squirrel (Ictidomys tridecemlineatus) was the main prey species, making up 29.7% of the diet (from a sample of 165).
In Kluane Lake, Yukon, 750 g (1.65 lb) Arctic ground squirrels (Spermophilus parryii) were the main overall food for Harlan’s red-tailed hawks, making up 30.8% of a sample of 1074 prey items. When these ground squirrels enter their long hibernation, the breeding Harlan’s hawks migrate south for the winter. Nearly as important in Kluane Lake was the 200 g (7.1 oz) American red squirrel (Tamiasciurus hudsonicus), which constituted 29.8% of the above sample. Red squirrels are highly agile dwellers on dense spruce stands, which has caused biologists to ponder how the red-tailed hawks are able to routinely catch them. It is possible that the hawks catch them on the ground such as when squirrels are digging their caches, but theoretically the dark color of the Harlan’s hawks may allow them to more effectively ambush the squirrels within the forests locally. While American red squirrel turn up not infrequently as supplementary prey elsewhere in North America, other tree squirrels seem to be comparatively infrequently caught, at least during the summer breeding season. It is known that pairs of red-tailed hawks will cooperative hunt tree squirrels at times, probably mostly between late fall and early spring. Fox squirrels (Sciurus niger), the largest of North America’s tree squirrels at 800 g (1.8 lb), are fairly regular supplemental prey but the lighter, presumably more agile 533 g (1.175 lb) eastern gray squirrel (Sciurus carolinensis) appears to be seldom caught based on dietary studies. While adult marmot may be difficult for red-tailed hawks to catch, young marmots are readily taken in numbers after weaning, such as a high frequency of yellow-bellied marmot (Marmota flaviventris) in Boulder, Colorado. Another grouping of squirrels but at the opposite end of the size spectrum for squirrels, the chipmunks are also mostly supplemental prey but are considered more easily caught than tree squirrels, considering that they are more habitual terrestrial foragers. In central Ohio, eastern chipmunks (Tamias striatus), the largest species of chipmunk at an average weight of 96 g (3.4 oz), were actually the leading prey by number, making up 12.3% of a sample of 179 items.
Outside of rodents, the most important prey for North American red-tailed hawks is rabbits and hares, of which at least 13 species are included in their prey spectrum. By biomass and reproductive success within populations, these are certain to be their most significant food source (at least in North America). Adult Sylvilagus rabbits known to be hunted by red-tails can range from the 700 g (1.5 lb) brush rabbit (Sylvilagus bachmani) to the Tres Marias rabbit (Sylvilagus graysoni) at 1,470 g (3.24 lb) while all leporids hunted may range the 421.3 g (14.86 oz) pygmy rabbit (Brachylagus idahoensis) to hares and jackrabbits potentially up twice the hawk’s own weight. While primarily crepuscular in peak activity, rabbits and hares often foraging both during day and night and so face almost constant predatory pressure from a diverse range of predators. Male red-tailed hawks or pairs which are talented rabbit hunters are likely have higher than average productivity due to the size and nutrition of the meal ensuring healthy, fast-growing offspring. Most widely reported are the cottontails, which the three most common North America varieties softly grading into mostly allopatric ranges, being largely segregated by habitat preferences where they overlap in distribution. Namely, in descending order of reportage were: the eastern cottontail (Sylvilagus floridanus), the second most widely reported prey species overall in North America and with maximum percentage known in a given study was 26.4% in Oklahoma (out of 958 prey items), the mountain cottontail (Sylvilagus nuttallii), maximum representation being 17.6% out of a sample of 478 in Kaibab Plateau, Arizona and the desert cottontail (Sylvilagus audubonii), maximum representation being 22.4% out of a sample of 326 in west-central Arizona. Black-tailed jackrabbits (Lepus californicus) are even more intensely focused upon as a food source by the hawks found in the west, particularly the Great Basin. This species is likely the largest prey routinely hunted by red-tails, and the mean prey size where jackrabbits are primarily hunted is the highest known overall. When jackrabbit numbers crash, red-tailed hawk productivity tends to decline as well. In northern Utah, black-tailed jackrabbits made up 55.3% by number of a sample of 329. Elsewhere, they are usually somewhat secondary by number. Mean sizes of jackrabbits taken can range up to approximately 2,114 g (4.661 lb), but probably quantitatively mostly juvenile and yearling jackrabbits are caught. Prime adult jackrabbits, with weights at times exceeding 2,700 g (6.0 lb), are difficult and taken infrequently, short of by particularly large and aggressive female red-tails. Other even larger species are sometimes taken as prey such as the white-tailed jackrabbit (Lepus townsendii), but whether this includes healthy adults, as they average over 3,200 g (7.1 lb), is unclear.
In the boreal forests of Canada and Alaska, red-tails are fairly dependent on the snowshoe hare (Lepus americanus), falling somewhere behind the great horned owl and ahead of the northern goshawk in their regional reliance on this food source. The hunting preferences of red-tails who rely on snowshoe hares is variable. In Rochester, Alberta, 52% of snowshoe hares caught were adults, such prey estimated to average 1,287 g (2.837 lb), and adults, in some years, were six times more often taken than juvenile hares, which averaged an estimated 560 g (1.23 lb). 1.9–7.1% of adults in the regional population of Rochester were taken by red-tails, while only 0.3–0.8 of juvenile hares were taken by them. Despite their reliance on it, only 4% (against 53.4% of the biomass) of the food by frequency here was made up of hares. On the other hand, in Kluane Lake, Yukon, juvenile hares were taken roughly 11 times more often than adults, despite the larger size of adults here, averaging 1,406.6 g (3.101 lb), and that the overall prey base was less diverse at this more northerly clime. In both Rochester and Kluane Lake, the number of snowshoe hares taken was considerably lower than numbers of ground squirrels taken. The differences of average characteristics of snowshoe hares that were hunted may be partially due to habitat (extent of bog openings to dense forest) or topography. Another member of the Lagomorpha order has been found in the diet, the much smaller American pika (Ochotona princeps), at 150 g (5.3 oz), but is not known to be common prey.
A diversity of mammals may be consumed opportunistically outside of the main food groups of rodents and leporids, but usually occur in low numbers. At least five species each are taken of shrews and moles, ranging in size from their smallest mammalian prey, the cinereus (Sorex cinereus) and least shrews (Cryptotis parva), which both weigh about 4.4 g (0.16 oz), to Townsend's mole (Scapanus townsendii), which weighs about 126 g (4.4 oz). A respectable number of the 90 g (3.2 oz) eastern mole (Scalopus aquaticus) were recorded in studies from Oklahoma and Kansas. Four species of bat have been recorded in their foods. The red-tailed hawks local to the large cave colonies of 12.3 g (0.43 oz) Mexican free-tailed bats (Tadarida brasiliensis) in Texas can show surprising agility, some of the same hawks spending their early evening and early morning hours in flight patrolling the cave entrances in order to stoop suddenly on these flighted mammals. Larger miscellaneous mammalian prey are either usually taken as juveniles, like the nine-banded armadillo (Dasypus novemcinctus), or largely as carrion, like the Virginia opossum (Didelphis virginiana). Small carnivorans may be taken, usually consisting of much smaller mustelids, like the 150.6 g (5.31 oz) long-tailed weasel (Neogale frenata), which was surprisingly widely taken as a supplemental prey species. Adult ringtails (Bassariscus astutus), which are about the same weight as a red-tailed hawk at 1,015 g (2.238 lb), are taken as prey occasionally. Larger carnivoran remains are sometimes found amongst their foods, but most are likely taken as juveniles or smaller range adults, or otherwise consumed only as carrion. Some of the relatively larger carnivorans red-tailed hawks have been known to eat have included red fox ( Vulpes vulpes), kit fox (Vulpes macrotis), white-nosed coati (Nasua narica), raccoon (Procyon lotor), striped skunk (Mephitis mephitis) and domestic cats (Felis catus). A red-tailed hawk was filmed killing a small cat in a city area. Many of these medium-sized carnivorans are probably visited as roadkill, especially during the sparser winter months, but carrion has turned up more widely than previously thought. Some nests have been found (to the occasional "shock" of researchers) with body parts from large domestic stock like sheep (Ovis aries), pigs (Sus domesticus), horses (Equus caballus ) and cattle (Bos taurus) (not to mention wild varieties like deer), which red-tails must visit when freshly dead out on pastures and take a couple talonfuls of meat. In one instance, a red-tailed hawk was observed to kill a small but seemingly healthy lamb. These are born heavier than most red-tails at 1,500 g (3.3 lb) but in this case, the hawk was scared away before it could consume its kill by the rifle fire of the shepherd who witnessed the instance.


Like most (but not all) Buteo hawks, red-tailed hawks do not primarily hunt birds in most areas, but can take them fairly often whenever they opportune upon some that are vulnerable. Birds are, by far, the most diverse class in the red-tailed hawk’s prey spectrum, with well over 200 species known in their foods. In most circumstances where birds become the main food of red-tailed hawks, it is in response to ample local populations of galliforms. As these are meaty, mostly terrestrial birds which usually run rather than fly from danger (although all wild species in North America are capable of flight), galliforms are ideal avian prey for red-tails. Some 23 species of galliforms are known to be taken by red-tailed hawks, about a third of these being species introduced by humans. Native quails of all five North American species may expect occasional losses. All 12 species of grouse native to North America are also occasionally included in their prey spectrum. In the state of Wisconsin, two large studies, from Waupun and Green County, found the main prey species to be the ring-necked pheasant (Phasianus colchicus), making up 22.7% of a sample of 176 and 33.8% of a sample of 139, respectively. With a body mass averaging 1,135 g (2.502 lb), adult pheasants are among the largest meals that male red-tails are likely to deliver short of adult rabbits and hares and therefore these nests tend to be relatively productive. Despite being not native to North America, pheasants usually live in a wild state. Chickens (Gallus gallus domesticus) are also taken throughout North America, with all Wisconsin studies also found large numbers of them, making up as much as 14.4% of the diet. Many studies reflect that free-ranging chickens are vulnerable to red-tailed hawks although somewhat lesser numbers are taken by them overall in comparison to nocturnal predators (i.e. owls and foxes) and goshawks. In Rochester, Alberta, fairly large numbers of ruffed grouse (Bonasa umbellus) were taken but relatively more juveniles were taken of this species than the two other main contributors to biomass here, snowshoe hare and Townsend’s ground squirrel, as they are fairly independent early on and more readily available. Here the adult grouse was estimated to average 550 g (1.21 lb) against the average juvenile which in mid-summer averaged 170 g (6.0 oz).
Beyond galliforms, three other quite different families of birds make the most significant contributions to the red-tailed hawk’s avian diet. None of these three families are known as particularly skilled or swift fliers, but are generally small enough that they would generally easily be more nimble in flight. One of these are the woodpeckers, if only for one species, the 131.6 g (4.64 oz) northern flicker (Colaptes auratus), which was the best represented bird species in the diet in 27 North American studies and was even the fourth most often detected prey species of all. Woodpeckers are often a favorite in the diet of large raptors as their relatively slow, undulating flight makes these relatively easy targets. The flicker in particular is a highly numerous species that has similar habitat preferences to red-tailed hawks, preferring fragmented landscapes with trees and openings or parkland-type wooded mosaics, and often forage on the ground for ants, which may make them even more susceptible. Varied other woodpecker species may turn up in their foods, from the smallest to the largest extant in North America, but are much more infrequently detected in dietary studies. Another family relatively often selected prey family are corvids, which despite their relatively large size, formidable mobbing abilities and intelligence are also slower than average fliers for passerines. 14 species of corvid are known to fall prey to red-tailed hawks. In the Kaibab Plateau, the 128 g (4.5 oz) Steller's jay (Cyanocitta stelleri) were the fourth most identified prey species (10.3% of the diet). 453 g (0.999 lb) American crows are also regularly detected supplemental prey in several areas. Even the huge common raven (Corvus corax), at 1,050 g (2.31 lb) at least as large as red-tailed hawk itself, may fall prey to red-tails, albeit very infrequently and only in a well-staged ambush. One of the most surprising heavy contributors are the icterids, despite their slightly smaller size and tendency to travel in large, wary flocks, 12 species are known to be hunted. One species pair, the meadowlarks, are most often selected as they do not flock in the same ways as many other icterids and often come to the ground, throughout their life history, rarely leaving about shrub-height. The 100.7 g (3.55 oz) western meadowlark (Sturnella neglecta), in particular, was the third most often detected bird prey species in North America. Red-winged blackbirds (Agelaius phoeniceus) which are probably too small, at an average weight of 52.4 g (1.85 oz), and fast for a red-tailed hawk to ever chase on the wing (and do travel in huge flocks, especially in winter) are nonetheless also quite often found in their diet, representing up to 8% of the local diet for red-tails. It is possible that males, which are generally bold and often select lofty perches from which to display, are most regularly ambushed. One bird species that often flocks with red-winged blackbirds in winter is even better represented in the red-tail’s diet, the non-native 78 g (2.8 oz) European starling (Sturnus vulgaris), being the second most numerous avian prey species and seventh overall in North America. Although perhaps most vulnerable when caught unaware while calling atonally on a perch, a few starlings (or various blackbirds) may be caught by red-tails which test the agile, twisting murmurations of birds by flying conspicuously towards the flock, to intentionally disturb them and possibly detect lagging, injured individual birds that can be caught unlike healthy birds. However, this behavior has been implied rather than verified.
Over 50 passerine species from various other families beyond corvids, icterids and starlings are included in the red-tailed hawks' prey spectrum but are caught so infrequently as to generally not warrant individual mention. Non-passerine prey taken infrequently may include but are not limited to pigeons and doves, cuckoos, nightjars, kingfishers and parrots. However, of some interest, is the extreme size range of birds that may be preyed upon. Red-tailed hawks in Caribbean islands seem to catch small birds more frequently due to the paucity of vertebrate prey diversity here. Birds as small as the 7.7 g (0.27 oz) elfin woods warbler (Setophaga angelae) and the 10 g (0.35 oz) bananaquit (Coereba flaveola) may turn up not infrequently as food. How red-tails can catch prey this small and nimble is unclear (perhaps mostly the even smaller nestlings or fledglings are depredated). In California, most avian prey was stated to be between the size of a starling and a quail. Numerous water birds may be preyed upon including at least 22 species of shorebirds, at least 17 species of waterfowl, at least 8 species of heron and egrets and at least 8 species of rails, plus a smaller diversity of grebes, shearwaters and ibises. These may range to as small as the tiny, mysterious and "mouse-like" black rail (Laterallus jamaicensis), weighing an average of 32.7 g (1.15 oz), and snowy plover (Charadrius nivosus), weighing an average of 42.3 g (1.49 oz) (how they catch adults of this prey is not known), to some gulls, ducks and geese as heavy or heavier than a red-tailed hawk itself.
How large of a duck that red-tailed hawks can capture may be variable. In one instance, a red-tailed hawk failed to kill a healthy drake red-breasted merganser (Mergus serrator), with this duck estimated to weigh 1,100 g (2.4 lb), later the same red-tail was able to dispatch a malnourished red-necked grebe (Podiceps grisegena) (a species usually about as heavy as the merganser), weighing an estimated 657 g (1.448 lb). However, in interior Alaska, locally red-tailed hawks have become habitual predators of adult ducks, ranging from 345 g (12.2 oz) green-winged teal (Anas carolinensis) to 1,141 g (2.515 lb) mallard (Anas platyrhynchos). Even larger, occasionally adult Ross's goose (Chen rossii), weighing on average 1,636 g (3.607 lb), have been killed as well. Also, a non-native Egyptian goose (Alopochen aegyptiaca), in which adults average 1,762 g (3.885 lb), was killed by a red-tail in Texas. There are several known instances of predation on adult greater sage grouse (Centrocercus urophasianus), although mainly females are reported taken, these averaging 1,200 to 1,745 g (2.646 to 3.847 lb) depending on region. Some adult male sage grouse may have been attacked but, as these average from 2,100 to 3,190 g (4.63 to 7.03 lb), this needs verification. Even larger, in at least once case a grown hatch-year bird was caught of the rare, non-native Himalayan snowcock (Tetraogallus himalayensis), this species averaging 2,428 g (5.353 lb) in adults. Red-tailed hawks are a threat to the poults typically of the wild turkey (Meleagris gallopavo). However, in one instance, an immature red-tail was observed trying to attack an adult female turkey, which would weigh about 4,260 g (9.39 lb) (on average). However this red-tail was unable to overpower the turkey hen. Additionally, young domestic turkeys, weighing up to at least 1,500 g (3.3 lb) or more, have been killed by red-tailed hawks. Other than wild turkeys, other larger birds occasionally lose young to red-tails such as trumpeter swans (Cygnus buccinator), sandhill cranes (Grus canadensis) and great blue herons (Ardea herodias).


As easily one of the most abundant of all American raptorial birds, red-tailed hawks have been recorded as interacting with every other diurnal bird of prey. Due to the extreme dietary plasticity of red-tails, the food habits of other birds of prey regularly overlap considerably with red-tails. Furthermore, due to its ability to nest in varied habitats, home ranges also frequently abut those of other raptor species. The most obvious similar species in their range are other Buteo hawks, especially larger species with a similar ecological niche. Two of the larger, more widespread other Buteos are the Swainson's hawk and the ferruginous hawks and, as with many other birds of prey, red-tailed hawks occur in almost the entirety of these birds' breeding ranges. These species have broadly similar breeding season diets, especially the ferruginous and red-tailed hawks. In some areas, such as Snake River NCA the diets of the two species consist of more than 90% of the same species and body mass of prey taken was similar. Therefore, all three large Buteo hawks defend their territories from each other with almost the same degree of dedication that they defend from others of their own species. In some cases, territorial clashes of Swainson's hawks and red-tailed hawks can last up to 12 hours, however, the birds involved are usually careful to avoid physical contact. Due to the similarities of the foods and their aggressive dispositions towards one another, these Buteos need some degree of partitioning in order to persist alongside one another and this usually is given by habitat preferences. The ferruginous hawk prefers open, practically treeless prairie while of these, the red-tailed hawks prefers the most wooded areas with large trees, while the Swainson's hawk prefer roughly intermediate areas. Where the habitat is more open, such as in Cassia County, Idaho, the Swainson's and ferruginous hawks have the advantage in numbers and red-tails are scarce. However, habitat alterations by humans, such as fire suppression and recovering pasture, usually favor the red-tailed hawk and are to the detriment of the other two species. These practices have caused range expansions of many other species of birds but declines in many others. Of these three Buteo species, the Swainson's hawk is most dissimilar, being a long-distance migrant which travels to South America each winter and, for much of the year, prefers to prey on insects (except for during breeding, when more nutritious food such as ground squirrels are mainly fed to the young). It also breeds notably later than the other two species. Surprisingly, although it's slightly smaller in body mass and has notably smaller (and presumably weaker) feet than ferruginous and red-tailed hawks, the Swainson's is actually usually (but not invariably) dominant in territorial conflicts over the other two. Part of this advantage is that the Swainson's hawk is apparently a superior flier both in long and short-distance flights, with its more pointed wing shape and lower wing loading allowing it more agile, sustained and speedier flight that the bulkier hawks cannot match. Therefore, in north-central Oregon, Swainson's hawks were shown to be more productive, in prairie located trees, and partially displaced prior-breeding red-tails several times, although overall breeding success rates were not perceptibly decreased in the latter hawk. In the Chihuahuan Desert of Mexico, Swainson's hawks usually nested in lowlands and red-tails nested in highlands but interspecies conflicts nevertheless were apparently quite frequent. Usually, the habitat preferences of red-tailed hawks and ferruginous hawks are discrepant enough to keep serious territorial conflicts to a minimum. However, red-tailed hawks and ferruginous hawks occasionally engaged in kleptoparasitism towards one another, usually during winter. Red-tails may be somewhat dominant based on prior reports in food conflicts but the ferruginous hawk may also win these. Where they overlap, the hawk species may adjust their daily routine to minimize contact, which tends to be costly of time and energy and may cause the hawks to abandon their nests for long stretches of time, which in turn leaves their young vulnerable to predation. When habitats change rapidly, often due to human interference, and they nest more closely than natural partitioning would allow, in all three nesting success can decline significantly.
Beyond the Swainson's and ferruginous hawks, six other Buteos co-occur with red-tailed hawks in different parts of North America. Many of these are substantially smaller than red-tails and most serious territorial conflicts with them are naturally mitigated by nesting in deeper wooded areas. One other larger species, the rough-legged buzzard, mostly nests far north of the breeding range of red-tailed hawks. However, in Alaska they sometimes nest in the same areas. The rough-legged buzzards are both cliff and tree nesters and areas used by the two species are not necessarily mutually exclusive but each seems to avoid the other, in part by differing breeding schedules. Wintering rough-legged buzzards may regularly come into conflict over food with red-tailed hawks and seem to be subordinate to the red-tails, with several records of them being chased off both kills and carrion by the red-tailed hawks. During winter their hunting habits may keep them somewhat separate, the rough-legged being a much more aerial hunter, but rough-legged buzzards usually withdrew if a red-tailed hawk flew towards them. There is at least one case, however, of a rough-legged buzzard being the victor of a conflict over a kill with a red-tailed hawk. Red-tailed hawks are conspicuously more aggressive and tend to be dominant over slenderer, medium-sized Buteos such as red-shouldered hawks and zone-tailed hawks (Buteo albonotatus). In Massachusetts, red-shoulder hawks used mixed forests and hardwoods as nesting habitat while red-tails most often used in pitch pine and stunted oaks on Cape Cod. Nesting range overlap here most often occurred on white pine forests. As habitat has opened over time, red-tailed hawks frequently took over former red-shouldered hawk territories, even using their nests in two cases. In north-central Florida, it was found during winter that red-shouldered and red-tailed hawk habitat usage blurred and, because the local habitat favors red-shouldered hawks, they easily outnumbered the number of red-tailed hawks in the area. Therefore, again with sufficient habitat partitioning, the two species can live near one another without negatively effecting one another. In the American southwest and Texas, two relatively large buteonine hawks also live alongside red-tailed hawks, the Harris's hawk (Parabuteo unicinctus) and the white-tailed hawk (Geranoaetus albicaudatus). Usually, habitat preferences kept conflicts to a minimum, with the red-tailed hawk favoring taller, more isolated saguaro cactus for nesting, whereas the other species outnumbered red-tails in areas that were denser and more shrubby. The Harris's hawk was determined to be a superior aerial hunter over red-tailed hawks, and could take down flying birds more routinely.
Hawks and kites from outside the buteonine lineage are usually substantially smaller or at least different enough in diet and habitat to largely avoid heavy conflict with red-tailed hawks. On occasion, northern harriers (Circus hudsonius) which have much lower wing loading, will mob red-tailed hawks out of their home ranges but in winter the red-tails seem to be dominant over them in conflicts over food. Among Accipiter hawks, the most similar to the red-tailed hawk in diet and size is the northern goshawk. In some areas, the prey species of these can be very similar and North American populations of goshawks take many more squirrels and leporids than their Eurasian counterparts do. It was found that the feet and striking force of hunting goshawks was more powerful than that of the red-tailed hawk, despite the red-tails being up to 10% heavier in some parts of North America. Therefore, wild goshawks can dispatch larger prey both on average and at maximum prey size, with some victims of female goshawks such as adult hares and galliforms such as turkey and capercaillie weighing up to or exceeding roughly 4,000 g (8.8 lb). In a comparative study in the Kaibab Plateau of Arizona, however, it was found that red-tailed hawks had several population advantages. Red-tails were more flexible in diet, although there was a very broad overlap in prey species selected, and nesting habitat than the goshawks were. As red-tailed hawks in conflict with other more closely related Buteo hawks rarely (if ever) result in mortality on either side, goshawks and red-tailed hawks do seem to readily kill one another. Adults of both species have been shown to be able to kill adults of the other.
The great horned owl occupies a similar ecological niche nocturnally to the red-tailed hawk. There have been many studies that have contrasted the ecology of these two powerful raptors. The great horned owl averages heavier and larger footed, with northern populations averaging up to 26% heavier in the owl than the hawk. However, due in part to the red-tail’s more extensive access to sizable prey such as ground squirrels, several contrasting dietary studies found that the estimated mean prey size of the red-tailed hawk, at 175 g (6.2 oz), was considerably higher than that of the great horned owl, at 76 g (2.7 oz). Also, the diet of red-tailed hawk seems to be more flexible by prey type, as only just over 65% of their diet is made of mammals, whereas great horned owls were more restricted feeders on mammals, selecting them 87.6% of the time. However, the overall prey spectrum of great horned owls includes more species of mammals and birds (but far less reptiles) and the great horned owl can attack prey of a wider size range, including much larger prey items than any taken by red-tailed hawks. Mean prey weights in different areas for great horned owls can vary from 22.5 to 610.4 g (0.79 to 21.53 oz), so is far more variable than that of red-tailed hawks (at 43.4 to 361.4 g (1.53 to 12.75 oz)) and can be much larger (by about 45%) than the largest estimated size known for the red-tailed hawk's mean prey weight but conversely the owl can also subsist on prey communities averaging much smaller in body size than can support the hawk. Some prey killed by great horned owls was estimated to weigh up to 6,800 g (15.0 lb). Great horned owls and red-tailed hawks compete not only for food but more seriously over nesting areas and home ranges. Great horned owls are incapable of constructing nests and readily expropriate existing red-tail nests. The habitat preferences of the two species are quite similar and the owl frequently uses old red-tail nests, but they do seem to prefer more enclosed nest locations where available over the generally open situation around red-tailed hawk nests. Sometimes in warmer areas, the owls may nest sufficiently early to have fledged young by the time red-tails start to lay. However, when there is a temporal overlap in reproductive cycles, the owl sometimes takes over an occupied red-tail nest, causing desertion. Red-tailed hawks have an advantage in staple prey flexibility as aforementioned, while great horned owl populations can be stressed when preferred prey is scarce, especially when they rely on leporids such as hares and jackrabbits. For example, in Alberta, when snowshoe hares were at their population peak, red-tailed hawks did not increase in population despite taking many, with only a slight increase in mean clutch size, whereas the owls fluctuated in much more dramatic ways in accordance with snowshoe hare numbers. The red-tails migratory behavior was considered as the likely cause of this lack of effect, whereas great horned owls remained through the winter and was subject to winter-stress and greater risk of starvation. As a nester, great horned owl has the advantage in terms of flexibility, being somewhat spread more evenly across different habitats whereas in undisturbed areas, red-tailed hawks seem to nest more so in clusters where habitat is favorable. Predatory relationships between red-tailed hawks and great horned owls are quite one-sided, with the great horned owl likely the overall major predator of red-tails. On the other hand, red-tailed hawks are rarely (if ever) a threat to the great horned owl. Occasionally a red-tailed hawk can strike down an owl during the day but only in a few singular cases has this killed an owl. Most predation by the owls on the hawks is directed at nestlings at the point where the red-tails' nestlings are old enough that the parents no longer roost around the nest at night. Up to at least 36% of red-tailed hawk nestlings in a population may be lost to great horned owls. Adult and immature red-tailed hawks are also occasionally preyed upon at night by great horned owls in any season. In one case, a great horned owl seemed to have ambushed, killed and fed upon a full-grown migrating red-tail even in broad daylight. Occasionally, both red-tails and great horned owls will engage each other during the day and, even though the red-tailed hawk has the advantage at this time of day, either may succeed in driving away the other. Despite their contentious relations, the two species may nest quite close to one another. For example, in Saskatchewan, the smallest distance between nests was only 32 to 65 m (105 ft 0 in to 213 ft 3 in). In these close proximity areas all owl nests succeeded while only two red-tail nests were successful. In Waterloo, Wisconsin, the two species were largely segregated by nesting times, as returning red-tailed hawks in April–June were usually able to successfully avoid nesting in groves holding great horned owls, which can begin nesting activities as early as February. In Delaware County, Ohio and in central New York state, divergence of hunting and nesting times usually allowed both species to succeed in nesting. In all three areas, any time the red-tails tried to nest closer to great horned owls, their breeding success rates lowered considerably. It is presumable that sparser habitat and prey resources increased the closeness of nesting habits of the two species, to the detriment of the red-tails. Due to nesting proximity to great horned owls, mature red-tails may have losses ranging from 10 to 26%.
Red-tailed hawks may face competition from a very broad range of predatory animals, including birds outside of typically active predatory families, carnivoran mammals and some reptiles such as snakes. Mostly these diverse kinds of predators are segregated by their hunting methods, primary times of activity and habitat preferences. In California, both the red-tails and western diamondback rattlesnakes (Crotalus atrox) live mainly on California ground squirrel, but the rattlesnake generally attacks the squirrels in and around their burrows, whereas the hawks must wait until they leave the burrows to capture them. Hawks have been observed following American badgers (Taxidea taxus) to capture prey they flush and the two are considered potential competitors, especially in sparse sub-desert areas where the rodent foods they both favor are scarce. Competition over carcasses may occur with American crows, and several crows, usually about six or more, working together can displace a hawk. Another avian scavenger, the turkey vulture (Cathartes aura), is dominated by red-tails and may be followed by red-tails in order to supplant a carcass found by the vulture with their keen sense of smell. In some cases, red-tailed hawks may be considered lessened as food competitors by their lack of specialization. For instance, no serious competition probably occurs between them and Canada lynx (Lynx canadensis) despite both living on snowshoe hares.
Distinguishing territorial exclusionary behavior and anti-predator behavior is difficult in raptorial birds. However, as opposed to other medium to largish hawks which chase off red-tails most likely as competition, in much smaller raptors such as kestrels and smaller Accipiter hawks, their aggressive reaction to red-tailed hawks is almost certainly an anti-predator behavior. Although less prolific than goshawks, some eagles and, especially, great horned owls, red-tailed hawks can and do prey upon smaller birds of prey. The following species of accipitrid have been known to fall prey to red-tailed hawks, potentially including nestlings, fledglings, immatures and/or adults: swallow-tailed kite (Elanoides forficatus), Mississippi kite (Ictinia mississippiensis), white-tailed kite (Elanus leucurus), northern harrier (Circus hudsonius), sharp-shinned hawk (Accipiter striatus), Cooper's hawk (Accipiter cooperii), goshawks, gray hawk (Buteo plagiatus), red-shouldered hawk and broad-winged hawk (Buteo platypterus). These species range from the 135.7 g (4.79 oz) sharp-shinned hawk, the smallest North American accipitrid, to the goshawk, which at 956 g (2.108 lb) is nearly red-tailed hawk sized. Additionally, there are records of red-tailed hawks hunting 9 species of owl, ranging in size from the 104.2 g (3.68 oz) northern saw-whet owl (Aegolius acadius) to juveniles of the 1,079 g (2.379 lb) great gray owl (Strix nebulosa) and seemingly adults of the 717 g (1.581 lb) barred owl (Strix varia). Red-tails will also hunt falcons including adult American kestrels (Falco sparverius) and merlins (Falco columbarius) and presumed nestlings of the peregrine falcon (Falco peregrinus). When hunting other raptorial birds, red-tailed hawks seem to ambush them from a perch, diving suddenly and unexpectedly upon spotting the quarry and tend to have the greatest success when the raptorial prey is distracted, such as those migrating on windy days, feeding on their own prey and tending to their nest.
In turn, red-tailed hawks may engage in behavior that straddles territorial exclusion and anti-predator behavior to the two much larger raptors in North America which actively hunt, the eagles. Red-tails are most commonly seen flying towards and aggressively displacing both flying bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos), but may also, to the contrary, unobtrusively duck down out of flight to an inconspicuous perch when an eagle is spotted. The behavioral variation is probably related to the activity of hawks, which may feel the need to protect their nests and food resources while actively breeding but are not usually willing to risk their lives in attacking an eagle while migrating or wintering. At times mobbing behavior of smaller raptors may cause both eagles to turn over and present their large talons to their attacker, which can be dangerous for the smaller hawk. Besides the great horned owl, the two eagle species are the only known animals known to regularly threaten red-tailed hawks of any age. In particular, the golden eagle is probably the greatest daytime threat to fledged immature and adult red-tails, as these have turned up in many dietary studies of the powerful eagle. Less efficient as a predator of red-tails, bald eagles nonetheless have been recording killing adults in some cases or, more often, depredating red-tailed hawk nests. On occasion, this may result in the bald eagle bringing the nestling red-tails to their own nest and, for some reason, not killing them. In some cases, the bald eagles inadvertently actually raise the nestling red-tails themselves and the baby red-tailed hawks may successfully fledge. In one case, a red-tailed hawk was observed to kill a bald eagle chick, whether this was predatory or competitive, it quickly abandoned the dead nestling after the eagle’s parents returned. On several tropical islands, which are often shared only with other hawks, owls and falcons of only medium or small size and typically lack larger raptors or carnivorans, the red-tailed hawk may be the largest native predator and will, in these cases, be considered the apex predator. Other than large birds of prey, extensive records of predation on red-tailed hawks is surprisingly poor, in spite of several populations recording nestlings and eggs disappearing through presumed acts of natural predation. The most likely major predator of eggs and nestlings that disappear is the raccoon which, during its nocturnal foraging, is a notorious enemy of nearly any kind of birds nest. It is also known that unidentified large snakes, probably consisting of the same species that the red-tails so readily predate during broad daylight, will prey upon nestling red-tails. In California, common ravens were recorded preying on the downy young of red-tailed hawks. Other corvids, including blue jays (Cyanocitta cristata), California scrub jays (Aphelocoma californica) and crows, are known to feed on eggs and small nestlings either when nest attendance is atypically low by the hawks or when they can successful harass the parent hawks via mobbing so severely that they temporarily leave the nest. Blackflies (Simulium canonicolum) have been recorded as killing several red-tail chicks through blood loss. There are also several cases of possible prey turning the tables on red-tailed hawks and either maiming or killing them. This is especially true of snakes, with some prey species of Pituophis, Pantherophis and Coluber known to overpower and nearly kill, often the hawk survives only if by human intervention. Not infrequently prey such as coral snakes and rattlesnakes may succeed in killing red-tailed hawks with their venom, even if they themselves are also killed and partially consumed. Peregrine falcons are also known to kill red-tailed hawks that have come too close to their nests by stooping upon them.


The pair constructs a stick nest most often in a large tree 4 to 21 m (13 to 69 ft) off the ground. They may too nest on virtually any man-made structures with some variety of ample ledges or surface space and good views of the surrounding environment (i.e. powerline poles, radio transmission towers, skyscraper buildings). Much variation is recorded in nest usage behavior, many red-tails build new nests every year despite prior nests sometimes being in good standing and unoccupied, some may reuse a nest in subsequent years or may leave a nest for a year and then come back to it the following year. A red-tailed hawk nest is typically located in a gradient zone between woods with tall, mature trees, if available, and openings whether this is composed of shrubland, grassland or agricultural areas. Nest sites vary greatly in topography and vegetative composition. While tree nests are largely preferred, occasionally they nest on cliff ledges may be utilized even where other nest sites are presumably available. Cliff nests may be located at 35 m (115 ft) or higher above the nearest flat ground. At times, unlike great horned owls, red-tailed hawks have been recorded nesting in surprisingly unbroken forests. In North Dakota, nest sites tend to be concentrated along wooded river drainages. Compared to Swainson's hawks and ferruginous hawks, red-tailed hawk nests are usually in taller trees and are closer to waterways. In Puerto Rico, nests are most often found in transitional zone between dry lowlands and mountainous cloud forests, with trees typically taller than their neighbors to allow views of more than half of their home ranges. More than 21 tree species were recorded used in Puerto Rico. Tree species is seemingly unimportant to red-tailed hawks. In some parts of Arizona, saguaro cactus were used exclusively as nesting sites. Alternately, old nests of other Buteo hawks, corvids, golden eagles and even leaf nests of tree squirrels have also been used by red-tailed hawks. Both members of the pair will build the nests but the female spends more time forming the bowl, with the greatest activity often in the morning and nest building completed in a week or less. The nest is generally 71 to 97 cm (28 to 38 in) in diameter, with a mean of roughly 76 cm (30 in), and can be up to 96 cm (38 in) tall after several years use. The inner bowl averages about 37 cm (15 in) wide and 13 cm (5.1 in) deep. The nest is constructed of twigs, and lined with bark, pine needles, corn cobs, husks, stalks, aspen catkins, or other plant lining matter. Lining the nest may be for warning other red-tails of the active use of a nest. In moderate to northern climes, red-tailed hawks tend to face to the south or west, presumably to make them less vulnerable to strong northeasterly storm winds.


In most of the interior contiguous United States the first egg is laid between mid-March and early April, ranging from 3 to 5 weeks after the nest is constructed, with the clutch completed 2 to 5 days after the initial egg is laid. The average date of the laying the first egg can be variable: peaking mid-January in Puerto Rico, averaging 9 March in Arizona, 26 March in the Front Range Urban Corridor and 1 May in Alberta. The mean initiation of clutches may bump weeks later if 10 cm (3.9 in) or more of snow is still on the ground in Wisconsin during March. A clutch of one to three eggs is laid in March or April, depending upon latitude, with four eggs being uncommon and five and perhaps even six increasingly rare. Clutch size depends almost exclusively on the availability of prey for the adults. At the species level, body size also determines clutch size. For example, while the total clutch weighs up to 18% of the females weight and the clutch size averages 2 to 3, a larger raptor like the golden eagle lays a smaller clutch, usually not more than two, that weighs less than 10% in total of the female’s body mass, whereas a smaller raptor like the kestrel lays a larger clutch averaging five that weighs 50% of the females weight. Average clutch size vary from 1.96 in Alaska when prey populations were low up to 2.96 in Washington. Eggs are laid approximately every other day. Average egg sizes in height and width (each with a sample size of 20) are in the following subspecies- B. j. borealis: 59.53 mm × 47.49 mm (2.344 in × 1.870 in); B. j. calurus: 60.04 mm × 47.1 mm (2.364 in × 1.854 in); B. j. fuertesi: 59.42 mm × 46.99 mm (2.339 in × 1.850 in). The eggs of red-tailed hawks are mostly white, sometimes with a faint buffy wash; at times the eggs manifest a sparsely or heavily marked with blotches of buff, pale reddish-brown, dark brown, or purple. The markings often appear indistinctly and may combine to form a fine speckling. They are incubated primarily by the female, with the male substituting when she leaves to hunt or merely stretch her wings. Rarely do the males incubate more than four hours of daylight. The male brings most food to the female while she incubates.


After 28 to 35 days of incubation (averaging about three days longer in the Caribbean as does fledgling as compared to North American red-tails), the eggs hatch over 2 to 4 days. Like most raptorial birds, the nestlings are altricial and nidicolous at hatching. Hatchlings average 58 g (2.0 oz) in body mass with no difference in sizes of the sexes until the young are about 29 days old for mass and 21 days or so for external linear standard measurements such as bill and talon size. The female broods them while the male provides most of the food to the female and the young, which are also known as eyasses (pronounced "EYE-ess-ez"). The female feeds the eyasses after tearing the food into small pieces. The young red-tails are active by the second day when they issue soft peeping calls, bounce, and wave continuously with their wings. By day 7, the bouncing and peeping begin to wane, and young start to peck at prey in their nest. Nestlings emit high whistling notes (usually in response to adults overhead) by day 10, sit up on tarsometatarsi by day 15, become aggressive toward intruders by day 16, strike out with talons and wings by day 21, begin to stretch wings and exercise regularly by day 30. After 42 to 46 days, the eyasses begin to leave the nest and tear apart prey for themselves. The amount of food brought to the nest daily varies considerably, based on brood size and prey availability. In Alberta, an average of 410 to 730 g (14 to 26 oz) is brought each day for 1 to 3 nestlings while in Washington, it was estimated a minimum of 520 g (1.15 lb) per day for 1 surviving nestling and in Wisconsin, an estimated 219 g (7.7 oz) was needed for 1 nestling and 313 g (11.0 oz) for 2. Brooding is strenuous for parent red-tails and both members of the pair usually lose some weight, especially the female. Some females may lose over 100 g (3.5 oz) between hatching and fledging. During brooding the female may become aggressive to intruders, including humans. In the east, red-tailed hawk females rarely defend nests from humans but historically in California and quite often still in Alaska, some female will dive repeatedly and "savagely", sometimes snapping off large branches in her temper, occasionally stunning herself or inadvertently knocking down her own youngster if it is attempting to fledge. Apparently, the less extensive prior exposure they have to humans may make mature females more aggressive towards humans near the nest. Although development is asynchronical in most nests, runting may sometimes be recorded and even siblicide may occur, with the parents feeding the weaker, younger chicks less so and both the siblings and parents occasionally aggressively pecking the "runts" of the nest. Ultimately, the runt in such cases does not usually survive and may be either found crushed in the nest, discarded out of the nest after starvation or consumed by the parents or the siblings. However, as a whole, such killings are fairly rare and only occur when food supplies are extremely low, often this being in sync with poor spring weather (such as overly rainy or cold conditions). If there is too much food, such as California ground squirrels in California, the parents will discard remains after a day or two since decomposition of their prey invites infection, other diseases and blood-sucking insects to the nest that may endanger the nestlings. However, after about four weeks, the female often stops discarding leftover prey and the increased presence of flies may form somewhat of a risk to disease in the young but may also merely get the young to leave the nest sooner. One nest in California had two females and one male attended to; the male performed his usual function but both females would brood and tend to the nest. Additionally, bald eagles have been recorded to occasionally adopt red-tail fledglings into their nests. As recorded in Shoal Harbor Migratory Bird Sanctuary located near Sydney, British Columbia, on 9 June 2017, a juvenile red-tailed hawk was taken by a pair of bald eagles back to their nest, whereupon the chick, originally taken as prey, was accepted into the family by both the parents and the eagles' three fledglings. After surviving six weeks amongst the eagles, the fledgling, nicknamed "Spunky" by birdwatchers, had successfully begun learning to hunt and fly, showing that the aggressive hawk was able to survive amongst a nest of much larger adoptive siblings.


Young typically leave the nest for the first time and attempt their first flights at about 42–46 days after hatching but usually they stay very near the nest for the first few days. During this period, the fledglings remain fairly sedentary, though they may chase parents and beg for food. Parents deliver food directly or, more commonly, drop it near the young. Short flights are typically undertaken for the first 3 weeks after fledgling and the young red-tails activity level often doubles. About 6 to 7 weeks after fledging, the young begin to capture their own prey, which often consists of insects and frogs that the young hawks can drop down to onto the ground with relative ease. At the point they are 15 weeks old, they may start attempts to hunt more difficult mammal and bird prey in sync with their newly developed skills for sustained flight, and most are efficient mammal predators fairly soon after their first attempts at such prey. Shortly thereafter, when the young are around 4 months of age, they become independent of their parents. In some extreme cases, juvenile red-tails may prolong their association with their parents to as long as they are half a year old, as was recorded in Wisconsin. After dispersing from the parental territory, juveniles from several nests may congregate and interact in a juvenile staging area. Although post-fledgling siblings in their parents care are fairly social, they are rarely seen together post distribution from their parents range. Usually, newly independent young hawks leave the breeding area and migrate, if necessary, earlier than adults do, however the opposite was true in the extreme north of Alaska, where adults were recorded to leave first. Immature hawks in migratory populations tend to distribute further in winter than adults from these populations do. Immatures attempting to settle for the winter often are harassed from territory to territory by older red-tails, settling only in small, marginal areas. In some cases, such as near urban regions, immatures may be driven to a small pockets of urban vegetation with less tree cover and limited food resources. When a distant adult appears, immatures may drop from a prominent perch to a more concealed one. In some cases, hungry immature red-tails have been recorded making attempts at hunting prey beyond their capacities, expending valuable energy, such as healthy adults of larger carnivorans such as coyotes (Canis latrans), foxes and badgers and healthy flying passerines. There are some cases of red-tailed hawks, presumably younger than two years of age, attempting to breed, often with an adult bird of the opposite sex. Such cases have been recorded in Alberta, Arizona and Wisconsin, with about half of these attempts being successful at producing young. However, while adult plumage and technically sexual maturity is attained at two years old, many red-tails do not first successfully breed until they are around 3 years of age.


Breeding success is variable due to many factors. Estimated nesting success usually falls between 58% and 93%. Nesting success rates are probably drive primarily by prey populations, regional habitat composition, competition levels with other red-tailed hawks, predation rates (often due to great horned owls or perhaps raccoons) and human disturbance levels. In Oregon specifically, nesting success varied primarily based on "dispersion and density of perches" secondarily to ground squirrel abundance and whether the nest of other pairs red-tails was directly visible from a nest. Repeated disturbances at the nest early in the nesting cycle may cause abandonment of eggs or nestlings in some cases, but seemingly pairs are less likely to abandon the young later in the season in cases of human disturbance. 30% of nesting deaths in a study from Wisconsin were from nestlings falling to their death or the nest collapsing. In Puerto Rico, habitat appeared to be the primary driver of breeding success, as in lowland pastures nesting success was 43% producing a mean number of fledglings of 1.5 whereas in cloud forest success was 34% producing a mean of 0.7 fledglings. A modelling study in Puerto Rico showed that, apart from adult survival, nestling survival had the second greatest influence on population growth. In Wyoming, 12 pairs on a 12 square mile tract produced an average of 1.4 young per pair. In comparison, the mean number of fledglings was 0.96 in Michigan, 1.36 in Montana and was 1.4 in the Appalachians. In Wisconsin, the number of young successfully to fledge ranged from 1.1 to 1.8 from year to year probably depending on staple prey numbers. The record lifespan in wild for a red-tailed hawk is 25 years and 5 months from banding studies. In comparison, lifespans of up to 29.5 years have been recorded in captivity. In the wild, other red-tailed hawks have lived for at least 25 years, for example, Pale Male was born in 1990, and in Spring 2014 is still raising eyasses. However, of 5195 banded wild red-tailed hawks in one bander’s recordings, only 31 were reported to have survived to 17 years of age and only 11 survived for 20 years. The average mortality rate at 1 year of age for red-tails is 54% and thereafter is around 20% from banding sources. The estimated average lifespan of red-tailed hawks who attain maturity, per Palmer (1988), was claimed as only 6 to 7 years. The main causes of mortality considered as electrocution on power lines, other collisions, shooting, consumption of poisoned baits set for other animals and collision with vehicles and other crafts. While most mortality of young red-tails is at least mainly due to natural causes, mortality of fledged or older red-tails is now mostly attributable to human killing, accidental or intentional, as well as flying into manmade materials. Hawks in urban areas are threatened by the use of rat traps and poisoned bait to kill rodents. This generally consists of warfarin cookies which induce internal bleeding in rats and mice, and a hawk that ingests rodents who have consumed rat poison can itself be affected. Red-tailed hawks are also vulnerable to fatal bacterial infections include peritonitis, myocarditis, granulamotous, sarcocystosis and mycobateriosis as well as some forms of viral infection, to which immature hawks especially, as they often have less access to coverage in poor weather conditions, are most vulnerable. Neither this nor other Buteo hawks were found to be highly susceptible to long-term DDT egg-shell thinning due to being part, generally, of relatively short, terrestrial-based food chains.


The red-tailed hawk is a popular bird in falconry, particularly in the United States where the sport of falconry is tightly regulated; this type of hawk is widely available and is frequently assigned to apprentice falconers. Red-tailed hawks are highly tameable and trainable, with a more social disposition than all other falcons or hawks other than the Harris's hawk. They are also long lived and fairly disease resistant, allowing a falconer to maintain a red-tailed hawk as a hunting companion for potentially up to two decades. There are fewer than 5,000 falconers in the United States, so despite their popularity any effect on the red-tailed hawk population, estimated to be about one million in the United States, is negligible.
Not being as swift as falcons or accipiters, red-tailed hawks are usually used to hunt small game such as rabbits and squirrels, as well as larger quarry such as Hares. However, some individuals may learn to ambush game birds on the ground before they are able to take off and accelerate to full speed, or as they have fly into cover after a chase. Some have even learned to use a falcon-like diving stoop to capture challenging game birds such as pheasants in open country.
In the course of a typical hunt, a falconer using a red-tailed hawk most commonly releases the hawk and allows it to perch in a tree or other high vantage point. The falconer, who may be aided by a dog, then attempts to flush prey by stirring up ground cover. A well-trained red-tailed hawk will follow the falconer and dog, realizing that their activities produce opportunities to catch game. Once a raptor catches game, it does not bring it back to the falconer. Instead, the falconer must locate the bird and its captured prey, "make in" (carefully approach) and trade the bird off its kill in exchange for a piece of offered meat.


The feathers and other parts of the red-tailed hawk are considered sacred to many indigenous people and, like the feathers of the bald eagle and golden eagle, are sometimes used in religious ceremonies and found adorning the regalia of many Native Americans in the United States; these parts, most especially their distinctive tail feathers, are a popular item in the Native American community. As with the other two species, the feathers and parts of the red-tailed hawk are regulated by the eagle feather law, which governs the possession of feathers and parts of migratory birds.


The rough-legged buzzard or rough-legged hawk (Buteo lagopus) is a medium-large bird of prey. It is found in Arctic and Subarctic regions of North America, Europe, and Russia during the breeding season and migrates south for the winter. It was traditionally also known as the rough-legged falcon in such works as John James Audubon's The Birds of America.
Nests are typically located on cliffs, bluffs or in trees. Clutch sizes are variable with food availability, but three to five eggs are usually laid. These hawks hunt over open land, feeding primarily on small mammals. Along with the kestrels, kites, and osprey, this is one of the few birds of prey to hover regularly.


The rough-legged hawk is a member of the genus Buteo, a group of moderately large raptors exhibiting broad wings, short tails and wide robust bodies. This group is known as hawks in North America but referred to as buzzards in Europe.
There are at least three recognized subspecies of Buteo lagopus:
B. l. lagopus is the nominate subspecies. It breeds in northern Europe and Asia and has relatively dark plumage. The dorsal feathers are a homogeneous brown colour, contrasting well with the paler head.
B. l. sanctijohannis breeds in North America. It has pale, speckled dorsal plumage and is slightly smaller than B. l. lagopus.
B. l. kamtchatkensis breeds from north Siberia to Pacific North America. It has paler plumage when compared with B. l. sanctijohannis and it is, on average, the largest of the three subspecies.


The rough-legged hawk breeds in tundra and taiga habitats of North America and Eurasia between the latitudes of 61° and 76° N. Rough-legged hawks occurring in North America migrate to southern Canada and into the central United States for the winter, while Eurasian individuals migrate to southern Europe and Asia. It is the only member of its diverse genus found in both of the Northern continents and has a complete circumpolar distribution. During these winter months, from November to March, preferred habitats include marshes, prairies and agricultural regions where rodent prey is most abundant.
Breeding sites are usually located in areas with plenty of unforested, open ground. Depending on snow conditions, migrants arrive at breeding grounds during April and May. Home ranges vary with food supply but are commonly reported to be 10–15 km² (3.9–5.8 sq mi) during the winter, but little is known about home ranges during the breeding season. Although frequently attacked in skirmishes by other highly territorial birds such as gyrfalcons and skuas, the rough-legged hawk is not strongly territorial. However, wintering rough-legged hawks seems to behave aggressively towards common buzzards in Sweden and both species with try to keep the other off a fixed hunting range.


This species is carnivorous, typically feeding on small mammals, which make up 62–98% of its diet. Lemmings and voles are the major prey items of this species, seasonally comprising up to 80–90% of their prey, but this varies with seasonal availability. Some evidence suggests that these hawks may be able to see vole scent marks which are only visible in the ultraviolet range, allowing them to cue in on prey. Despite generally preying on rodents, a 2015 paper reported the species breeding on rodent-free Kolguev Island in Arctic Russia with goslings a main prey. In the North-West of Russia, rough-legged hawks could feed on small rodents, in the years when rodent density is high, and shift for alternative prey (ptarmigans and hares) in the years when small rodents are scarce. The rough-legged hawk will also supplement its diet with mice, rats, gerbils, pikas, shrews, squirrels of the genera Spermophilus and Tamias, and insects. Besides mammals, birds are the second most favored type of prey for rough-legs. Most avian prey species are small passerines such as snow buntings (Plectrophenax nivalis), Lapland longspur (Calcarius lapponicus) and American tree sparrow (Spizelloides arborea). However, they will also prey on birds slightly larger than the passerines typically targeted, especially ptarmigan (Lagopus ssp.), as well as waterfowl, shorebirds (such as ruffs (Philomachus pugnax)) and short-eared owls (Asio flammeus). They usually target bird prey which are young and inexperienced, with relatively large avian prey often being snatched in their fledging stage. When small mammals are scarce, the rough-legged hawk will also feed on larger, medium-sized mammals including prairie dogs (Cynomys ssp.), ground squirrels, muskrats (Ondatra zibethicus), weasels (Mustela ssp.), and even adult black-tailed jackrabbits (Lepus californicus) of approximately twice their own weight. During winter, shrub-steppe habitats seem to encourage a strong dependence on rabbit prey. In developed areas of England, wintering rough-legged buzzards have been recorded preying most regularly on relatively large prey such as common wood pigeon (Columba palumbus) and invasive European rabbits (Oryctolagus cuniculus).
This avian predator hunts opportunistically, occasionally supplementing their diet with carrion, but focusing primarily on the most locally abundant small vertebrates. Rough-legged hawks will steal prey from other individuals of the same species as well as other species such as the red-tailed hawk, hen harrier (Circus cyaenus), American kestrel (Falco sparverius), and common raven (Corvus corax). Prey sizes typically range from 6.5–2,587 g (0.23–91.25 oz) and adults require 80–120 g (2.8–4.2 oz) of food daily, around the body mass of the largest species of vole or lemming although most species weigh a bit less. These raptors hunt during the daytime. Like most Buteos, rough-legged hawks have been reported both still-hunting (watching for prey from a perch and then stooping) and watching for prey while in flight. Unlike most other large raptors, they may engage in hovering flight above the ground while search for prey.


Sexual maturity is reached at about two years old. Breeding generally occurs during May but is variable depending upon dates of arrival at breeding grounds. The rough-legged hawk is thought to be monogamous, mating with a single individual for multiple years. No evidence currently suggest otherwise.
Rough-legged buzzards look for suitable nesting territory not in spring, like most migratory birds, but in advance - in autumn. After the breeding season, they make long-distance prospecting flights, look for a suitable habitat with high rodent numbers, and return to that place the following year.
Nests are built soon after arrival to breeding grounds and require 3–4 weeks to complete. Twigs, sedges, and old feathers are used as building materials. Nests are 60–90 cm (24–35 in) in diameter and 25–60 cm (9.8–23.6 in) in height. Cliff ledges and rocky outcroppings are preferred nesting sites. Females can lay 1–7 eggs but will typically lay 3–5. Average egg size is 56.4 mm (2.22 in) in length by 44.7 mm (1.76 in) in width. Minimum incubation period is 31 days, provided almost exclusively by the female. The male feeds the female during this incubation period. After hatching, young require 4–6 weeks before fledging the nest. Fledglings depend on parents to provide food for 2–4 weeks after leaving the nest.
Rough-legged hawks could nest in association with Peregrine falcons (Falco peregrinus). Peregrines chasing away small rodent predators from their nesting territory and Rough-legged Hawks could use these hot spots as a nesting territory.


Rough-legged hawks that survive to adulthood can live to an age of 19 years in the wild. One female being kept in an Idaho zoo is over 25 years of age and there is a female that is a minimum of 38 years old living in Redding, CA as of 2015. However, perhaps a majority of individuals in the wild do not survive past their first two years of life. The threats faced by young rough-legs can include starvation when prey is not numerous, freezing when Northern climes are particularly harsh during brooding, destruction by humans, and predation by various animals. The chances of survival increase incrementally both when they reach the fledging stage and when they can start hunting for themselves. Death of flying immatures and adults are often the result of human activity, including collisions with power lines, buildings, and vehicles, incidental ingestion of poison or lead from prey or illegal hunting and trapping.
Most predation recorded on this species is on the young at the nest. Arctic foxes (Vulpes lagopus), brown bears (Ursus arctos), and wolverines (Gulo gulo) have all eaten eggs and young of this species if they are capable of accessing nests on foot. Avian scavengers, especially maurading groups of common ravens, will also readily prey on eggs and nestlings, as will skuas (Stercorarius ssp.). Snowy owls (Bubo scandiacus) are a potential predator at the nest as well. Adults, being a large raptorial bird, have fewer natural predators but may die in conflicts, especially if they are defending their own nests and are occasionally preyed on by other large raptorial birds. Raptors who prey on rough-legged hawks of most ages at varied times of year may include numerous eagles (especially the golden eagle (Aquila chrysaetos), though also sometimes other Aquila in Eurasia and seldom Haliaeetus eagles) as well as large falcons. While wintering, rough-legged buzzards or hawks may be vulnerable to predation by night to Eurasian eagle-owls (Bubo bubo) or great horned owls (Bubo virginianus) and rarely, during day, other large Buteo hawks, including those of their own species.
Besides predation, it could be other reasons for nestling mortality among rough-legged buzzards. Nestlings in their first two weeks have a lousy temperature regulation. In the tundra landscape, they nest on the ground and during hot weather, they could go out of the nest seeking shelter from the sun. If weather then rapidly changes to the thunderstorm (which is common in the Arctic) nestlings could die without parent protection in a short time in 3–5 m from the nest. Other reasons for nestling mortality are earth-slides of the river-banks, where rough-legged buzzards often build their nests, and chilling.


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.
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.
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.
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.


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. 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, 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. 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.


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. Red-shouldered hawks select sites with greater tree species richness for nesting. 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. 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. 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. 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 predate 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. 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. 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.
Red-shouldered hawks have hybridized with gray hawks (Buteo plagiatus), red-tailed hawks (Buteo jamaicensis) and common black hawks (Buteogallus anthracinus).


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). 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.


The gray hawk (Buteo plagiatus) or Mexican goshawk is a smallish raptor found in open country and forest edges. It is sometimes placed in the genus Asturina as Asturina plagiata. The species was split by the American Ornithological Society (AOU) from the gray-lined hawk. The gray hawk is found from Costa Rica north into the southwestern United States.
The gray hawk is 46–61 cm (18–24 in) in length and weighs 475 g (16.8 oz) on average. The adult has a pale gray body, the tail is black with three white bands and the legs are orange. It is a solid, unpatterned gray on the upper parts.
Immature birds have dark brown upperparts, a pale-banded brown tail, brown-spotted white underparts and a brown streaked buff head and neck. This species is quite short-winged, and has a fast agile flight for a Buteo. The call is a shrill whistled kleee-ooo.
Gray hawks feed mainly on lizards and snakes, but will also take small mammals, birds and frogs. It usually sits on an open high perch from which it swoops on its prey, but will also hunt from a low glide. The nest is of sticks and built high in a tree. The usual clutch is one to three, usually two white to pale blue eggs. The young take about 6 weeks to fledging.