Short-tailed hawks occur in the Nearctic and Neotropical regions. In the United States, short-tailed hawks reside mainly in southern Florida. In recent years they have been expanding their range northward to southern Texas, Arizona, and New Mexico, although no breeding has yet been reported in these states. Their range extends from the northern areas of Mexico to as far south as northern Argentina. A related taxon, Buteo albigula, which occurs in the temperate zone of the Andes and parts of Chile, was formerly considered a subspecies of short-tailed hawks but it is now generally given full species status.
Many populations appear to be migratory. Populations in Mexico may migrate as far south as Costa Rica. The population in Florida is disjunct by about 800 km from other populations and is partially migratory. In that population, individuals breed throughout most of the peninsula north to north-central Florida, but migrate during the winter to the southern tip of the peninsula and some of the Florida Keys. Populations from Panama and throughout South America are not known to migrate.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
occurs (regularly, as a native taxon) in multiple nations
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Short-tailed hawk is resident locally in peninsular Florida (from St. Marks and San Mateo south to southern Dade County, in winter mostly south of Lake Okeechobee; AOU 1998); and from central Sonora and Tamaulipas in mexico south through Middle America and South America west of the Andes to western Ecuador and east of the Andes to northern Argentina, Paraguay, and southern Brazil (AOU 1998). This species apparently also nests in southeastern Arizona (Troy Cormon, pers. comm., 2005).
Regularity: Regularly occurring
Type of Residency: Year-round
Short-tailed hawks, one of the smaller species of Buteo, are crow-sized birds. They are 39 to 44 cm in length with a wingspan of 83 to 103 cm. The tail grows to 132 to 340 mm. Average mass is 441 grams. Females are larger than males, weighing on average 515 grams, while males weigh 392 grams on average. Though females are larger than males, the sexes are similar in the field. They have relatively long wings for their size; when perched, the wings reach the tail tip, giving these hawks their name due to the appearance of having an unusually short tail. In reality tail length is typical of the genus. The bill is black with a bluish-black base and a cere that varies from yellow to greenish-yellow. The legs and feet are light yellow to lemon yellow while the talons are black. The iris of Florida birds are dark brown in adults and lighter brown in juveniles. Museum specimens from tropical areas have irises ranging from yellow to yellowish-brown to brownish-yellow.
Short-tailed hawks occur in distinct light and dark color morphs with no intermediates. The light morph has white, unmarked underparts and underwing coverts while the head is a very dark blackish brown except for the anterior portions of the malar region, lores, chin, and throat, creating the effect of a dark hood. The upper parts and upper wing coverts are a uniform blackish brown with small patches of rufous brown on the sides of the upper breast, sides of the rump, and the scapulars. The tibial and crural feathers are pale buff. The under surface of the flight feathers is pale grayish with many narrow brownish bars and one wide dark terminal band along the trailing edge of the wing. The primaries are palest at the base of the outer first through fifth primaries, creating a diagnostic white oval. The rectrices appear grayish-brown above and grayish-white below with 4 to 5 narrow, incomplete brown bands and a dark terminal band. The tip of the tail feathers are pale gray. Sexes are alike.
The dark morph is almost entirely blackish brown. It lacks the rufous brown on the rump and scapulars and there is a small white patch where the lore and forehead meet. The underwing coverts are dark blackish brown except for the greater secondary and primary underwing coverts, which are mottled with white. The rest of the underwing appears the same as the light morph. Sexes are alike. In Florida, the dark morph is more numerous than the white. In other parts of the species’ range, the dark morph is uncommon or nonexistent.
Immature light morph short-tailed hawks have pale buff or orange-buff on the breast, belly, crural feathers, axillaries, and underwing coverts. The dark bands on the tail are heavier and more numerous than those on the adult, they are all roughly the same width. There are dark-brown streaks on the side of the breast and the edge of the feathers of the nape, scapulars, back, rump, and wing coverts have pale-brown or pale-buffy coloration. Instead of the hood of the adult, light-morph juveniles have ear coverts finely streaked with buff or pale ocher. Dark morph immature hawks have white spots and streaks on their chin, throat, belly, breast, axillaries, and under wing coverts.
There are two recognized subspecies of Buteo brachyurus: B. b. brachyurus and B. b. fuliginosus. Buteo brachyurus brachyurus is found in in South America. It can be distinguished from Buteo brachyurus fuliginosus by having less barring on the tail and no rufous on the side of the neck. Buteo brachyurus fuliginosus is found in Panama and the rest of the North American range. Though they are considered part of the same subspecies, the population of hawks in Florida appears to be larger-bodied than those living in Central and South America. They also have more rufous on their hind neck.
Range mass: 392 to 515 g.
Average mass: 441 g.
Range length: 39 to 44 cm.
Range wingspan: 83 to 103 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic
Sexual Dimorphism: sexes alike; female larger
Length: 39 cm
Weight: 530 grams
Adult differs from other southeastern U.S. buteos in being either all black or all white below (throat, breast, belly, and wing linings). Light-morph immature resembles immature broad-winged hawk and may not be separable in the field (Johnsgard 1990).
Habitat and Ecology
Short-tailed hawks breed mainly in tall, dense, wet forest patches near water, such as mangrove and cypress swamps. When not breeding, individuals can be found near coastal areas, forests, forested edges, pine savannas, pastures, suburban areas, and open country. They are not usually found in dense, closed forest. While they often roost and nest in larger trees, they hunt primarily in open country and on forest edges, where wind conditions are best for their unique style of hunting. Buteo brachyurus occurs primarily in lowland and foothill habitats, typically up to 2000 m elevation and occasionally to 3000 m. Robinson et al. (1994) reports short-tailed hawks inhabiting a wide range of habitats in Amazonian Peru, including lake, rivers, pantanal (seasonally flooded wetlands mainly in southern Brazil), transitional forests, and upland forests, though they were considered rare in all of these except pantanal, where they were considered uncommon.
Range elevation: 3000 (high) m.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; rainforest ; scrub forest
Aquatic Biomes: coastal
Other Habitat Features: suburban ; riparian ; estuarine
Comments: This species occurs in a wide range of habitats. Generally it occupaies open country, from mangrove and cypress swamps to open pine-oak woodland, avoiding heavily forested situations (AOU 1983). It is most common in mixed woodland-savanna habitats (Terres 1980). It hunts over open land.
Nests are in the tops of cypress, pine, or other trees, or in top of mangroves (Terres 1980). Nests may be in dense or open stands of tall trees in either flooded or upland locations, in tall straight trees near near edge of, or at small clearings in, woodlands, or near the tops of trees taller than the surrounding canopy (Palmer 1988), usually at a fork along the major trunk or larger lateral branch. Individuals build a new nest each year or, less often, reuse the same nest in successive years (Palmer 1988).
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Migratory in northern part of range in Florida, but moves only to southern Florida (during October and early November); disappears from wintering areas in southern Florida during February-March (Palmer 1988). Some migratory movement is suspected (but not well documented) in Mexico and Central America.
Short-tailed hawks feed mostly on smaller birds. In Florida, over half their bird diet is made up of eastern meadowlarks (Sturnella magna) and red-winged blackbirds (Agelaius phoeniceus), likely due to the conspicuousness of these species. They prey on adults of these species and have not been observed feeding on nestlings. When hunting, they hover or soar 50 to 300 meters high, with outstretched wings and head held down. From this position, they can dive on birds below. They also prey on lizards, snakes, rodents, and occasional insects (wasps and grasshoppers). They can catch prey on the wing, as well as when the prey is on a conspicuous perch. Ogden et al. (1974) report hunting success to be relatively low (~11%) with only 12 of 107 attempts being successful over the course of 30 hours of observation. Nestlings produce pellets of indigestible material about 30x12 mm in size.
Animal Foods: birds; mammals; reptiles; insects
Primary Diet: carnivore (Eats terrestrial vertebrates)
Comments: Florida: specialized hunter of small birds (mostly warbler to mourning dove size); mostly open terrain species; small rodents also recorded. Diet may be more varied in more tropical parts of range, though birds predominate; nonavian items include lizards, snakes, tree frogs, and insects (Palmer 1988). Hunts over forest canopy, along woodlands edges, and well out over adjacent marshes, rough pastures, or prairies; in Florida, hunts over large area, as much as 2-2.5 km in diameter; often searches ground from nearly stationary position in midair (Palmer 1988).
Short-tailed hawks are important predators, especially of birds, in the ecosystems they inhabit.
There are no known predators of adult short-tailed hawks. Crows have been known to rob the nest of eggs.
- American crows (Corvus brachyrhynchos)
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: This species is represented by a large number of occurrences (subpopulations) throughout the wide range. About 43 breeding season locations indicative of nesting have been documented in Florida since 1951 (Millsap et al. 1996).
100,000 to >1,000,000 individuals
Comments: Total population size has been estimated at 500,000-5,000,000 (Rich et al. 2004). This hawk is fairly common in Mexico and northern Central America (Howell and Webb 1995), generally uncommon elsewhere.
Rare and local in Florida. In southern Florida, this species is less numerous than red-tailed and red-shouldered hawks. State population may be fewer than 500.
Life History and Behavior
The voice of Buteo brachyurus is described as a high-pitched, prolonged “keeeea” and it is often given when humans approach the nest. They also give a "keeee" call at the nest site, especially when males return to incubating females. A "squeee" call is also given before or after copulation and sometimes by a female when she is receiving food from a male. During the non-breeding period, these birds are usually silent. Newly hatched chicks give chip calls singly or in series of 2 to 4. After about four days they will call for food with soft squeals.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Comments: In Florida, perches until conditions suitable for effortless soaring; may spend much of remainder of day in air; aerial activity ceases 1-2 hours before sunset, when bird returns to woodland to roost (Palmer 1988).
There is no information on lifespan or survivorship in short-tailed hawks. Recorded causes of death include being shot, as well as being hit by cars. Habitat destruction, especially of winter breeding grounds in Florida, may also contribute to death in short-tailed hawks. Ironically, short-tailed hawks have increased in density in some areas due to logging that has opened up more of the forest edge habitats that it prefers (Thiollay 1999).
- Thiollay, J. 1999. Responses of an avian community to rain forest degradation. Biodiversity and Conservation, 8: 513-534.
The breeding season of short-tailed hawks is from late January to July. These birds are presumed to be monogamous. Courtship consists of the male circling and undulating above the female who is perched at the nest site. The male then presents prey or nest material to the female. They have also been observed to grasp each others’ talons in the air and tumble earthward. Copulation begins with the male descending and landing near or on the female. He proceeds to give a two-note squeal before mounting for 5 to 7 seconds. Though one male was observed to have had 2 mates over three years, there is little information on the duration of pair bonds. There is no assortative mating between the two color morphs. During the breeding season short-tailed hawks becomes quite secretive and can then be difficult to locate.
Mating System: monogamous
Females create a platform nest made of sticks, lining the interior with finer twigs and soft material such as Spanish moss during incubation and hatching. Males gather nest materials. Nests are around 0.6 to 0.9 meters wide and 0.3 meters deep. Normally, they are located towards the top of taller trees, 9 to 29 meters up, in cypress swamps or mangroves. Less often, nest sites are found in the interior of both closed and open woods and the edges of hammocks. One to three preliminary nests may be constructed before a final nest is chosen. Nests may be reused year after year, and new nests are always located around the same area as previous ones. Only one brood is raised per season.
Buteo brachyurus normally lays two eggs, although clutch size varies from one to three eggs. Typically they are an unspotted bluish-white, although some have reddish brown speckling around the larger end. The eggs are short elliptical or nearly oval shape. The length of time between eggs in a clutch is unknown. Incubation lasts between 34 and 39 days. Females incubate eggs while males provisio females with food.
At hatching, young are covered in white natal down and weigh from 35 to 55 grams. About 2.5 to 3 weeks after hatching, a second layer of gray down is grown. Nestlings are brooded almost continuously as females are absent from the nest less than 10% of the time. Chicks are fed 2 to 3 times a day by both parents. Siblicide has not been well-documented in the species, although observations in captivity suggest that it is a possibility. Length of time to fledging is unknown. One specimen had a mass of 415 grams at fledging. In an estimated 45% of nests, at least one young is successfully raised. The age at sexual maturity is unknown; however first-year birds have not been observed breeding. The timing of molts in this species is also unknown.
Breeding interval: Short-tailed hawks breed once every year.
Breeding season: Short-tailed hawks breed from January to July.
Range eggs per season: 1 to 3.
Range time to hatching: 34 to 39 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Short-tailed hawk males and females both care for their young until they are fledged and independent.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
In southern Florida, nest building occurs primarily early from February to mid-March, most pairs completing nests by mid- to late March. In northern Florida, nest completion may extend into April. In Florida, most eggs are laid from mid-March to mid-April. Elsewhere, reported egg dates include March and May in Trinidad, April and October in Panama, March in Chiapas, and February and early April in Veracruz. Clutch size usually is 2, rarely 3. Incubation lasts about 5 weeks, by female (male provides food). Young are tended by both parents. Limited evidence suggests that at least some yearling females may attempt to nest.
Molecular Biology and Genetics
Barcode data: Buteo brachyurus
Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen.
Other sequences that do not yet meet barcode criteria may also be available.
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Statistics of barcoding coverage: Buteo brachyurus
Public Records: 1
Specimens with Barcodes: 2
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
- Least Concern (LC)
- Least Concern (LC)
- Least Concern (LC)
- Lower Risk/least concern (LR/lc)
- Lower Risk/least concern (LR/lc)
- Lower Risk/least concern (LR/lc)