The bicolored hawk (''Accipiter bicolor'') is a species of

bird of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predators h ...

in the family

Accipitridae The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...

. It is found in forest, woodland, second growth, plantations, and wooded savanna in southeastern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

, and northern and central

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

(as far south as northern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

). Though generally uncommon, it is the most common species of ''

Accipiter ''Accipiter'' is a genus of Bird of prey, birds of prey in the family Accipitridae. With 51 recognized species it is the most diverse genus in its family. Most species are called goshawks or sparrowhawks, although almost all New World species (ex ...

'' in most of its range, but it does not occur at altitudes above such as the highest parts of the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

Description

At in length and in weight, it is significantly smaller than the

northern goshawk The northern goshawk (; ''Accipiter gentilis'') is a species of medium-large bird of prey, raptor in the Family (biology), family Accipitridae, a family which also includes other extant diurnal raptors, such as eagles, buzzards and harrier (bird) ...

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...

and North America, and somewhat smaller than the

Cooper's hawk Cooper's hawk (''Accipiter cooperii'') is a medium-sized hawk native to the North American continent and found from southern Canada to Mexico. This species is a member of the genus ''Accipiter'', sometimes referred to as true hawks, which are f ...

of North America, but among the largest ''Accipiter'' hawks in Central and South America (only the rare grey-bellied hawk is larger). As in other ''Accipiter'' 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 Rufous () is a color that may be described as reddish-brown or brownish- red, as of rust or oxidised iron. The first recorded use of ''rufous'' as a color name in English was in 1782. However, the color is also recorded earlier in 1527 as a di ...

below. The thighs are always pure rufous (not always easily seen), and the underwing

coverts A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts The ear coverts are s ...

are white in the northern subspecies and rufous in the southern. Juveniles are very variable. They can be white,

buff Buff or BUFF may refer to: People * Buff (surname), a list of people * Buff (nickname), a list of people * Johnny Buff, ring name of American world champion boxer John Lisky (1888–1955) * Buff Bagwell, a ring name of American professional ...

or rufous below, and sometimes with dark streaks. Their upperparts are browner than in adults, and the thighs are sometimes paler.

Taxonomy

The bicolored hawk is a species in the genus ''

'' and is included in the family

. Three

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

are currently recognized. The bicolored hawk is also closely related to the Cooper's hawk (''A. cooperii'') and the

Gundlach's hawk Gundlach's hawk (''Accipiter gundlachi'') is a species of bird of prey in the family Accipitridae. It is one of 21 Endemism, endemic bird species of Cuba. The common name and Latin binomial commemorate the German-Cuban ornithologist Juan Gundlac ...

(''A. gundlachi''); these three form a superspecies. Until recently, the

Chilean hawk The Chilean hawk (''Accipiter chilensis'') is a bird of prey species belonging to the typical hawks. It breeds in Andes forests from central Chile and western Argentina south to Tierra del Fuego, from sea level to 2,700 m altitude (though birds ...

(''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.Accipiter bicolor
Globalraptors.org (2012-07-27). Retrieved on 2013-04-03. Four subspecies of ''A. bicolor'' are acknowledged. These are: *''A. b. bicolor'', which is found in Southeastern Mexico and south through northern South America. Adults have a black crown, slate upper parts and a blackish tail that displays two or three pale bars. The primaries are obscurely barred. *''A. b. fidens'', which occurs in Eastern and Southern Mexico. It is morphologically similar to ''A. b. bicolor'', but is larger in size and darker in color. *''A. b. pileatus'', living in Brazil. Adults are similar to ''A. b. bicolor'', but are much paler and have a pearl-grey collar. Under-wing coverts and thighs are rufous. *''A. b. guttifer''; located in South Bolivia and northern Argentina. The underparts of the adult are grey or extensively salmon rufous with large white spots and bars.

Habitat and distribution

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, Bolivia and to Chile. It mainly resides in forest, along forest edges and in clearings in tropical and locally subtropical zones, although its habitat is none too specialized. It may also reside in rain forest, drier, thinned forest, and palm savanna with gallery forest. 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 A riparian forest or riparian woodland is a forested or wooded area of land adjacent to a body of water such as a river, stream, pond, lake, marshland, estuary, canal, sink or reservoir. Etymology The term riparian comes from the Latin word '' ...

. 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.

Behaviour

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.gavião-bombachinha-grande (Accipiter bicolor) , WikiAves – A Enciclopédia das Aves do Brasil
WikiAves (2009-07-11). Retrieved on 2013-04-03.

Vocalisations

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. A barking "''kra-kra-kra-kr-kr-kr-ka''" may also be heard from both sexes. During incubation, males give a sharp "''kek''" vocalisation upon arrival to the nest with food, to which the female replies with a nasal "''wreh''".

Diet

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. At times, the bicoloured hawk may hunt in pairs. Most commonly, it feeds on smaller birds such as

thrushes The thrushes are a passerine bird family, Turdidae, with a worldwide distribution. The family was once much larger before biologists reclassified the former subfamily Saxicolinae, which includes the chats and European robins, as Old World flycat ...

and small

doves Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...

but has also been known to consume small mammals including

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most ...

s and reptiles. Several instances where the hawks attack groups of

squirrel monkeys Squirrel monkeys are New World monkeys of the genus ''Saimiri''. ''Saimiri'' is the only genus in the subfamily Saimirinae. The name of the genus is of Tupi origin (''sai-mirím'' or ''çai-mbirín'', with ''sai'' meaning 'monkey' and ''mirím'' ...

tamarins The tamarins are squirrel-sized New World monkeys from the family Callitrichidae in the genus ''Saguinus''. They are the first offshoot in the Callitrichidae tree, and therefore are the sister group of a clade formed by the lion tamarins, Goe ...

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.

Reproduction

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 Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetra ...

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. The eggs are

brooded Egg incubation is the process by which an egg, of oviparous (egg-laying) animals, develops an embryo within the egg, after the egg's formation and ovipositional release. Egg incubation is done under favorable environmental conditions, pos ...

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.Parental Care
People.eku.edu. Retrieved on 2013-04-03. The young

fledge Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...

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.