Bicolored hawk | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Accipitriformes |
Family: | Accipitridae |
Genus: | Astur |
Species: | A. bicolor |
Binomial name | |
Astur bicolor (Vieillot, 1817) | |
Subspecies [2] | |
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The bicolored hawk (Astur bicolor) is a species of bird of prey in the family Accipitridae. It is found in forest, woodland, second growth, plantations, and wooded savanna in southeastern Mexico, Central America, and northern and central South America (as far south as northern Argentina). [3] Though generally uncommon, it is the most common species of Astur in most of its range, but it does not occur at altitudes above 2,700 metres (8,900 ft) such as the highest parts of the Andes. [4]
The bicolored hawk was formally described in 1817 by the French ornithologist Louis Vieillot under the binomial name Sparvius bicolor. He specified Cayenne in French Guiana as the type locality. [5] [6] The bicolored hawk was formerly placed in the large and diverse genus Accipiter . In 2024 a comprehensive molecular phylogenetic study of the Accipitridae confirmed earlier work that had shown that the genus was polyphyletic. To resolve the non-monophyly, Accipiter was divided into five genera. [7] [8] The genus Astur was resurrected to accommodate 9 species, including the bicolored hawk, that had previously been placed in Accipiter. The resurrected genus had been introduced in 1799 by the French naturalist Bernard Germain de Lacépède. [9] The genus name is from Latin astur, asturis meaning "hawk". [10]
The bicolored hawk is also closely related to the Cooper's hawk (A. cooperii) and Gundlach's hawk (A. gundlachi); these three form a superspecies. [11] Until recently, the Chilean hawk (A. chilensis) from the colder, southernmost South America was treated as a race of A. bicolor but due to its differences in habitat preferences and plumages from the bicolored hawk, A. chilensis is now considered a full species. [12]
Four subspecies are recognised: [9]
At 34–45 centimetres (13–18 in) in length and 200–450 grams (7.1–15.9 oz) in weight, it is significantly smaller than the northern goshawk of Eurasia and North America, and somewhat smaller than the Cooper's hawk of North America, but it is among the largest hawks in Central and South America (only the rare grey-bellied hawk is larger). [4] As in other hawks, the female is far larger than the male. Adults are grey above with darker wings and crown, and a banded tail. The underparts typically vary from dark grey to very pale grey, but the southern subspecies can sometimes be rufescent below. The thighs are always pure rufous (not always easily seen), and the underwing coverts are white in the northern subspecies and rufous in the southern. [4] Juveniles are very variable. They can be white, buff or rufous below, and sometimes with dark streaks. Their upperparts are browner than in adults, and the thighs are sometimes paler. [4]
The bicolored hawk is widespread but uncommonly observed. Its range extends from Mexico to west Ecuador, the Guianas to Colombia, south to east Peru, through Amazonian Brazil to Paraguay, north-northwestern Argentina,north of Uruguay,Bolivia and to Chile. [15] It mainly resides in forest, along forest edges and in clearings in tropical and locally subtropical zones, [14] although its habitat is none too specialized. It may also reside in rain forest, drier, thinned forest, and palm savanna with gallery forest. [11]
Forest disturbance and fragmentation negatively affect the habitat and quantity of the bicolored hawk, which is most abundant in primary undisturbed forest or riparian forest. There are fewer hawks in disturbed habitats such as forests that have been logged, and even fewer in those fragmented habitats that provide greater than 66% forest cover. These hawks are rarely present in forests that provide less than 66% forest cover. [16]
The bicolored hawk is difficult to detect due to its shyness and inconspicuousness. Because of this behaviour, the bicolored hawk may be more common than it seems. [17]
Its vocalisations are mainly subdued and unnoticeable. Males have been heard to give a soft, clear whistle and females can emit a loud "cac cac cac" when around the nest and young. [13] A barking "kra-kra-kra-kr-kr-kr-ka" may also be heard from both sexes. [18] During incubation, males give a sharp "kek" vocalisation upon arrival to the nest with food, to which the female replies with a nasal "wreh". [19]
These hawks capture prey in a stealthy manner by flying through dense vegetation to ambush unsuspecting prey. They may also capture prey through aerial pursuit after inconspicuously sitting and watching their target. [20] At times, the bicoloured hawk may hunt in pairs. Most commonly, it feeds on smaller birds such as thrushes, mockingbirds and small doves, but has also been known to consume small mammals, including bats, as well as reptiles and large insects. [4] [21] [19] Southern race individuals (or females) are also known to take Chilean pigeons. [4] Several instances where the hawks attack groups of squirrel monkeys or tamarins have been witnessed. In addition, these hawks may follow groups of monkeys in order to feed on the insects that are exposed by the monkeys. [11]
Bicolored hawks breed in forest areas, choosing to build nests on tree branches and occasionally hanging vines. The nest is built in cooperation between the male and female and is constructed from dried sticks and leaves. Each breeding pair will normally build a new nest at the beginning of each breeding year. Copulation occurs after breeding activities such as feeding and nest building have been completed. Egg laying takes place approximately five weeks after copulation and the dull white eggs measure an average of 47.1 mm × 36.5 mm; clutches average 1–3 eggs. [22] The eggs are brooded for about three weeks by the female while the male forages for food. Bicolored hawk chicks are categorized as semi-altricial; the eyes are open at hatching but the chicks are not immediately mobile and are fed by the parents. [23] The young fledge around 30–36 days after hatching and the fledgling period spans nearly seven weeks, during which the young will return to the nest frequently for food until they become independent. [19]
The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds of prey with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-sized mammals, with a number feeding on carrion and a few feeding on fruit. The Accipitridae have a cosmopolitan distribution, being found on all the world's continents and a number of oceanic island groups. Some species are migratory. The family contains 255 species which are divided into 70 genera.
The Accipitrinae are the subfamily of the Accipitridae often known as the "true" hawks, including all members of Accipiter and the closely related genera Erythrotriorchis, and Megatriorchis. The large and widespread genus Accipiter includes goshawks, sparrowhawks, the sharp-shinned hawk and others. They are primarily woodland birds that hunt by sudden dashes from a concealed perch, with long tails, broad wings and high visual acuity facilitating this lifestyle. In light of recent genetic research, the kites of the traditional subfamily Milvinae may also belong to this group.
The shikra is a small bird of prey in the family Accipitridae found widely distributed in Asia and Africa where it is also called the little banded goshawk. The African forms may represent a separate species but have usually been considered as subspecies of the shikra. The shikra is very similar in appearance, as well as behavior, at least to some degree, to other species including the Chinese sparrowhawk, Eurasian goshawk and Eurasian sparrowhawk. They have a sharp two note call and have the typical flap and glide flight. Their calls are imitated by drongos and the common hawk-cuckoo resembles it in plumage. This species was formerly placed in the genus Accipiter.
The crested goshawk is a bird of prey in the family Accipitridae that is widely distributed in tropical Asia. It was formerly placed in the genus Accipiter.
The Levant sparrowhawk is a small bird of prey. It measures 32–38 cm (13–15 in) in length with a wingspan of 65–75 cm (26–30 in). The female is larger than the male, but the difference is not as marked as with Eurasian sparrowhawk. The adult male is blue-grey above, with dark wingtips, and barred reddish below.
The plumbeous kite is a bird of prey in the family Accipitridae that is resident in much of northern South America. It is migratory in the northern part of its range which extends north to Mexico. It feeds on insects which it catches either from a perch or while in flight.
The ornate hawk-eagle is a fairly large bird of prey from the tropical Americas. Formerly, some authorities referred to this species as the crested hawk-eagle, a name that may cause some confusion as it is more commonly used for an Asian eagle species. Like all eagles, it is in the family Accipitridae. This species has a feathered tarsus that marks it as a member of the Aquilinae or booted eagle subfamily. This species is notable for the vivid colors and bold markings of adults, which differ considerably from the far more whitish plumage of the juvenile bird. The ornate hawk-eagle ranges from central Mexico south through much of Central America and in a somewhat spotty but broad overall range into South America, including in the west apart from the Andes and broadly on the Atlantic side especially Brazil down to as far as Southeast Brazil and northern Argentina. This species is found largely in primary forests with tall trees, although can be found in many forest types.
Frances's sparrowhawk is a small bird of prey. This species was formerly placed in the genus Accipiter. The nominate subspecies, T. f. francesiae, is endemic to Madagascar, and the other subspecies are found in the Comoro Islands. The Anjouan sparrowhawk, also known as the Anjouan Island sparrowhawk, Ndzuwani goshawk or Joanna Island goshawk, was thought to be extinct until searches in the 1980s and in 2005 confirmed that it is still extant.
The grey goshawk is a strongly built, medium-sized bird of prey in the family Accipitridae that is found in eastern and northern Australia. The white morph of this species is known as the white goshawk. This species was formerly placed in the genus Accipiter.
The tiny hawk is a small diurnal bird of prey found in or near forests, primarily humid, throughout much of the Neotropics. It is primarily a bird-eater, and is known to prey on hummingbirds.
The red-thighed sparrowhawk, alternatively known as the red-legged sparrowhawk or western little sparrowhawk, is a species of sparrowhawk in the family Accipitridae from western and northern central Africa. This species was formerly placed in the genus Accipiter.
Gundlach's hawk is a species of bird of prey in the family Accipitridae. It is one of 21 endemic bird species of Cuba. The common name and Latin binomial commemorate the German-Cuban ornithologist Juan Cristobal Gundlach (1810–1896). It is threatened by habitat loss and human persecution.
Henst's goshawk is a species of bird of prey in the family Accipitridae. It is a large, diurnal bird endemic to the island of Madagascar. It is an obligate forest species that occurs at very low densities on the island and is rarely seen. It can only occupy the primary and secondary forests found within the island. Its natural habitats are subtropical or tropical dry forest, subtropical or tropical moist lowland forest, subtropical or tropical moist montane forest, and plantations.
The Madagascar sparrowhawk is a species of bird of prey in the family Accipitridae.
The black-mantled goshawk is a species of bird of prey in the family Accipitridae. It is found in the highlands of New Guinea. Its natural habitat is subtropical or tropical moist lowland forests. This species was formerly placed in the genus Accipiter.
The grey-bellied hawk or grey-bellied goshawk is a fairly large and rare species of forest-dwelling South American bird of prey in the family Accipitridae.
The rufous-breasted sparrowhawk, also known as the rufous-chested sparrowhawk and as the red-breasted sparrowhawk, is a species of bird of prey in the family Accipitridae. It is found in Angola, Democratic Republic of the Congo, Eritrea, Eswatini, Ethiopia, Kenya, Lesotho, Malawi, Mozambique, Rwanda, South Africa, South Sudan, Tanzania, Uganda, Zambia, and Zimbabwe.
The scissor-tailed kite, also known as African swallow-tailed kite or fork-tailed kite, is a bird of prey in the family Accipitridae. It is the only species placed in the genus Chelictinia. It is widespread in the northern tropics of Africa.
The Chilean hawk is a bird of prey species belonging to the family Accipitridae. It breeds in Andes forests from central Chile and western Argentina south to Tierra del Fuego, from sea level to 2,700 m altitude. Some winter apparently in the lowlands of NW Argentina.
Astur is a genus containing hawks, goshawks and sparrowhawk in the family Accipitridae. The species were formerly placed in the genus Accipiter.