SPECIES

Red-tailed Hawk Buteo jamaicensis Scientific name definitions

C. R. Preston and R. D. Beane
Version: 1.0 — Published March 4, 2020
Text last updated May 20, 2009

Diet and Foraging

Feeding

Main Foods Taken

Small to medium-sized mammals: rodents (Microtus spp., Peromyscus spp., Spermophilus spp.); rabbits (Sylvilagus spp.) and hares (Lepus spp.). Birds: pheasants (Phasianus colchicus) and quail (Colinus virginianus). Reptiles: bullsnakes (Pituophis spp.) and rattlesnakes (Crotalus spp.).

Microhabitat for foraging

See Habitat. Perch availability and prey vulnerability key factors determining foraging distribution (Preston 1990), although uplifts may be important when hunting from the air, especially above unbroken forest canopy in Puerto Rico (Snyder et al. 1987c, Santana and Temple 1988).

Food Capture And Consumption

Most hunting (60%–80%) in North America is done from an elevated perch, visually searching surrounding area for prey (Fitch et al. 1946b, Thiollay 1981a, Ballam 1984). More time spent hunting while flying above canopy than while perched in highland forests of Puerto Rico (Snyder et al. 1987c, Santana and Temple 1988). Small prey is typically taken to a feeding perch, where mammals are swallowed whole and birds are beheaded, plucked, and eaten (Brown and Amadon 1968) . Larger items are partially plucked and eaten on the ground, the remains often brought to a perch for continued feeding (Fitch et al. 1946b). Large carcasses are usually abandoned after several hours of feeding, but may be revisited for up 3–4 d in cold weather. Trees are favored hunting and feeding perches, but utility poles and wires, and fences 0-3 m and 6-12 m above ground level also used frequently (Cox 1978, Bohall and Collopy 1984, Langley 1999, Applegate et al. 2004). Reliance on perch-and-wait hunting method presumably relates to the relatively low length-width ratio in Red-tail wings, making this species poorly adapted for hunting in flight (Janes 1985). In nw. Arkansas, dark morphs use more densely covered perch sites than light morphs during winter (Preston 1980). Also hunts by cruising (alternate wingbeats and glides, often termed flap-and-glide) 10–50 m over open areas, soaring at higher altitudes, and occasionally, hovering (Bent 1937b, Palmer 1988f, Santana and Temple 1988). Soars more often during sunny, windy days (Preston 1981). When prey detected (usually on ground), hawk glides or flaps-and-glides downward, thrusts legs forward when about 3 m from prey, and usually makes impact with one foot slightly in front of the other. During the ensuing struggle, mammalian prey frequently bite the toes and legs of hawks (especially juveniles); many Red-tails bear scars of these encounters. Snakes usually seized near mid-body, then quickly bitten in the neck and head until dead (see Figure 3).

In thick spruce stands in interior Alaska, uses Accipiter-like hunting maneuvers, and may run on the ground to capture prey (Lowe 1978). At cave openings in Edwards Plateau region of Texas, captures Mexican Free-tailed Bats (Tadarida brasiliansis) by flying parallel to the bat stream, then setting wings, extending legs with open talons and stooping into the bat stream (Sprunt 1950b, Baker 1962b, Lee and Kuo 2001). At Frio Cave, Uvalde County, Texas most (90%) predation occurred during evening emergence; on average each hawk caught 2.8 bats per evening and 0.5 bats per morning (Lee and Kuo 20011). Sometimes uses sailing techniques to capture flying insects (Goss 1891). Also frequently hunts afoot for grounded insects Bent 1937b).

In rain and cloud forests of Puerto Rico, most attacks on Scaly-naped Pigeons (Columba squamosa) and other prey in or below canopy initiated from flight at least 35 m above canopy (Santana and Temple 1988). Similarly, most attacks on prey in lowlands of Puerto Rico initiated from flight (Santana and Temple 1988).

Cooperative hunting, whereby two hawks guard opposite sides of a tree, may sometimes be used to catch tree squirrels (Bent 1937b), and some individuals may steal, or “pirate” food from other Red-tails and other species, including Sharp-shinned Hawk, Rough-legged Hawk, and Northern Harrier (Palmer 1988f, Wilson 1994a, RDB). May occasionally be cannibalistic (Baxter 1906, Hagar 1957, Steffen 1977). Commonly feeds on fresh carrion, including domestic livestock, road-killed ungulates, hares, rabbits, and prairie dogs, especially in winter (Langley 2001, Palmer 1988f, Prior and Weatherhead 1991a). May cue on behavior of magpies, crows, ravens, and other raptors and generally displaces smaller scavengers from carcasses (Langley 2001, Prior and Weatherhead 1991a, CRP, RDB).

Diet

Major Food Items

In e. and midwesterm North America, voles (Microtus), mice (Peromyscus spp., Reithrodontomys spp., Mus musculus), rats (Sigmodon hispidus, Oryzomys palustris), and cottontails (Sylvilagus spp.) make up the bulk of the diet, but Ring-necked Pheasant (Phasianus colchicus), Northern Bobwhite (Colinus virginianus), and other birds and reptiles (e.g., Elaphe obsoleta) also taken regularly (Fischer 1893, Errington 1933, McAtee 1935, Craighead et al. 1969, Orians and Kuhlman 1956, Gates 1972, Sherrod 1978, Petersen 1979a, Preston 1990). Snowshoe hares (Lepus americanus), black-tailed jackrabbits (Lepus californicus), and ground squirrels (Spermophilus spp.) dominate the diet in w. and n. parts of North America (Fitch et al. 1946b, Craighead et al. 1969, Meslow and Keith 1966, Luttich et al. 1970, Smith and Murphy 1973a, Mcinvaille and Keith 1974, Adamcik et al. 1979, Palmer 1988f).

Other important prey include pocket gophers (Geomys spp., Thomomys spp.), waterfowl (Anas spp.), small birds (Sturnus vulgaris, Agelaius phoeniceus, Sturnella spp.), and snakes (Pituophis melanoleucus, Elaphe spp., Thamnophis spp., Crotalus spp.; Knight and Erickson 1976, Fitch and Bare 1978, Lowe 1978, and Millsap 1981). Compared with the frequency of nonvenomous snakes in the diet, and their relative abundance in the environment, venomous snakes are taken with less frequency than expected (Fitch et al. 1946b). The proximate causes for this are unknown, but Bent (Bent 1937b) reported an incident where a Red-tail was bitten and killed by a “rattlesnake”, and a Red-tail was found dead with a coral snake (Micrurus sp.) in its talons (Brugger 1989).

Tree squirrels (Sciurus spp., Tamiasciurus hudsonicus), chipmunks, amphibians, and insects are less important prey, and bats, shrews, and moles are taken rarely. Land crabs are a mainstay of the diet of soccorensis (on Soccoro I. Mexico; Brown and Amadon 1968). Mammals, including rodents (Mus musculus, Rattus rattus, Rattus norvegicus) and mongoose (Herpestes auropunctatus) dominate diet in all habitats in Puerto Rico, but incidence of birds (Bubulcus ibis, Butorides virescens, Rallus longirostris, Crotophaga ani, Asio flammeus, Numida meleagris, Gallus gallus, Columba squamosa, Zenaida aurita, Columbina passerina, Mimus polyglottos, Margarops fuscatus, Coereba flaveola, Quiscalus niger, Tiaris bicolor), reptiles and amphibians (Anolis cristatellus, A. cuvieri, A. evermanni, A gundlachi, Ameiva exsul, Alsophis portoricensis, Eleutherodactylus sp., Bufo marinus), and arthropods (Epilobocera sinuatifrons, Scolopendra sp., Orthocrycus arboreus) has been higher in highland than in lowland habitats in Puerto Rico (Santana and Temple 1988). Fresh carrion is readily eaten when available, especially in temperate winters.

Quantitative analysis

Dietary composition varies greatly among regions, seasons, and even among individuals. Diet has been quantified mainly from examination of pellets and prey remains at roost and nest sites. More easily digested prey, especially amphibians and most invertebrates, are presumably underestimated by these methods.

The following regional summaries of pellets and prey remains provide an overview of the relative importance of various prey items. In Wisconsin, winter dietary biomass: 44% cottontails (3–yr range 34%–59%), 28% (19%–38%) voles and mice (mostly Microtus pennsylvanicus, Peromyscus maniculatus, and Peromyscus leucopus), and 10% (0%–13%) Ring-necked Pheasants (Petersen 1979a). Spring: 38% (4–yr range 25%–48%) cottontails, 23% (12%–38%) Ring–necked Pheasants, 14% (11%–17%) squirrels (Sciurus spp., Tamiasciurus hudsonicus) and muskrats (Ondatra zibethicus), 10% (6%–17%) passerines and other small birds, and only 7% (3%–9%) voles and mice.

In North Dakota, birds (mostly waterfowl) and mammals (mostly ground squirrels) account for 63.3% and 32.7% of summer diet by frequency (Murphy 1997). In Utah, black-tailed jackrabbits 92%–95% (total mammals 99% of prey biomass consumed by breeders; Smith and Murphy 1973a). In Arizona, 72.6% mammals, mostly Nuttall's cottontail (Sylvilagus nuttallii) and golden-mantled ground squirrel (Spermophilus lateralis) and 26.6% birds (mostly Northern Flicker (Colaptes auratus) and Steller's Jay (Cyanocitta stelleri) by frequency in May-October diet (Gatto et al. 2005). Snakes 50% of dietary biomass in n.-central Washington, where there were few lagomorphs and no ground squirrels (Knight and Erickson 1976). In Alberta, 66% mammals (32% Spermophilus richardsonii, 17% Lepus californicus) and 34% birds (12% ducks; Luttich et al. 1970). In California, spring diet 61% (frequency) ground squirrels (Spermophilus beecheyi), 13% pocket gophers (Thomomys bottae), and 10% cottontails (Sylvilagus auduboni; Fitch et al. 1946b).

Generally, vertebrate prey size varies from 15 g (e.g., small mice, birds) to 2,000 g (black-tailed jackrabbit). Snakes up to 1.5 m long (400 g) are captured. In Puerto Rico dry and moist lowland habitats, 88% and 72% mammals, respectively. In Puerto Rican rain forest, 41% mammals, 27% birds, 12% reptiles and amphibians, and 20% arthropods, while in cloud forest 10% mammals, 29% birds, 47% reptiles and amphibians, and 13% arthropods (Santana and Temple 1988).

Food Selection and Storage

Opportunistic predator, focusing on largest prey (up to jackrabbit size) that is readily available (Brown and Amadon 1968; see Diet). Experimental evidence suggests that body size, activity, and “formidability” of potential prey may influence prey selection (Snyder 1975). In field experiments with a trained Red-tailed Hawk, a higher percentage of inferior individuals (e.g., smaller, lighter, leaner, lower packed-cell volume, more physical defects, more parasites) were captured from a prey species difficult to capture (gray squirrel, Sciurus carolinensis) than from a species that was relatively easy to capture (eastern chipmunk, Tamias striatus) (Temple 1987).

Adults may bring more food to the nest than young can eat, but excess food is usually carried away within a day or two (Brown and Amadon 1968, Preston 2000). Prey items too large to be carried to a feeding perch may be dragged to a protected site, partially consumed, and abandoned (Preston 2000).

Nutrition and Energetics

A caged adult Red-tailed Hawk ingested an average of 140 g/day, or 17% of its body weight (Palmer 1988f). Males consumed an average of 147 g/d (13% of body weight), and females an average of 136 g/d (11% of body weight) during fall–winter (Craighead et al. 1969). Males ingested only 82 g/d (7% of body weight), females only 85 g/day (7%) during spring-summer. Assuming an average winter daily intake of 135–145 g of prey, mostly small mammals, and a caloric density of 1.50 kcal/g live weight for small mammals, daily average energy intake for Red-tailed Hawks in winter is 202–218 kcal (Craighead et al. 1969). The daily average energy intake for summer may be as low as 123 kcal/kg/d in Wyoming (Craighead et al. 1969) and 102 kcal/kg/d in the Santa Monica Mountains of California (Soltz 1984). Estimated average adult energy expenditure in Missouri 128.9 kcal/kg/d in winter, 110.3 kcal/kg/d in summer (Diesel 1983).

Metabolism and Temperature Regulation

Daily metabolizable energy intake by captive Red-tails varied between 156-184 kcal/BW (Tabaka et al. 1996). Basal metabolic rate estimated in winter: 39.8 (Diesel 1983) to 44.5 (Wasser 1979) kcal/kg/d; in summer: 69.7 kcal/kg/d (Diesel 1983). Average heart rate of a female monitored for 10 d was 202 beats/min during the day, 134 beats/min at night; maxima immediately after sunrise and immediately before sunset (Busch et al. 1984). Mean body temperature of telemetered Red-tails over a 24–h period was 41.1°C, with an increased difference in body temperature between active and inactive periods in winter. Nighttime body temperatures were 3.2°C lower than during the day in response to food deficiency (Chaplin et al. 1984). At low ambient temperatures, Red-tails erect or “fluff” plumage and retract one leg into feathers; at high ambient temperatures (27°C) they seek shade and become inactive (Ballam 1984). Panting maintains a stable body temperature at ambient temperatures up to 34°C if no body movement occurs (Hayes 1978).

Drinking, Pellet-Casting, and Defecation

No information on drinking. Generally, one pellet cast/d, but one wild bird was observed to cast 21 pellets in 61 d (Fitch et al. 1946b). Mean number of cast regurgitated per day by captive hawks fed to satiety ranged from 0.3 to 1.4, with dry matter comprising 2-8% of total dry matter consumed (Tabaka et al. 1996). In an experimental situation, a minimum of 17 h 45 min elapsed between ingestion and pellet egestion (Fuller et al. 1979). No information on defecation rates available.

Red-tailed Hawk Figure 3. Red-tailed Hawk with prey.
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Figure 3. Red-tailed Hawk with prey.

In western states, this hawk catches and eats many species of snakes. By J. Schmitt.

Red-tailed Hawk Juvenile Red-tailed Hawk with Northern Flicker prey. Colorado Springs, CO. October.
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Juvenile Red-tailed Hawk with Northern Flicker prey. Colorado Springs, CO. October.

This image came from CLO's Birdshare Flickr Pool. The following link is to this contributer's Flickr stream or website. http://www.flickr.com/photos/dziegler/, Oct 13, 2008; photographer Darin Ziegler

Recommended Citation

Preston, C. R. and R. D. Beane (2020). Red-tailed Hawk (Buteo jamaicensis), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.rethaw.01