The rufous crab hawk (''Buteogallus aequinoctialis'') or rufous crab-hawk, is a

Near Threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

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 predat ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...

Accipitrinae The Accipitrinae are the subfamily of the Accipitridae often known as the "true" hawks, including all members of '' Accipiter'' and the closely related genera ''Microspizias'', '' Erythrotriorchis'', and ''Megatriorchis''. The large and wide ...

, the "true" hawks, of 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 ...

.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 24 July 2022. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved July 24, 2022 It is found on

Trinidad Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...

and along the

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 sou ...

n coastline from eastern

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

to southern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 24 July 2022. Species Lists of Birds for South American Countries and Territories. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved July 24, 2022

Taxonomy and systematics

The rufous crab hawk was formally described in 1788 by the German naturalist

Johann Friedrich Gmelin , fields = , workplaces = University of GöttingenUniversity of Tübingen , alma_mater = University of Tübingen , doctoral_advisor = Philipp Friedrich Gmelin Ferdinand Christoph Oetinger , academic_advisors = , docto ...

in his revised and expanded edition of

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...

's ''

Systema Naturae ' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial ...

''. He placed it with the eagles, hawks and relatives in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

'' Falco'' and coined the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...

''Falco aequinoctialis''. Gmelin based his description on the "Aequinoctial eagle" that had been described in 1781 by the English ornithologist John Latham from a specimen that formed part of a private collection in London. The specimen had come from

Cayenne Cayenne (; ; gcr, Kayenn) is the capital city of French Guiana, an overseas region and department of France located in South America. The city stands on a former island at the mouth of the Cayenne River on the Atlantic coast. The city's m ...

. The rufous crab hawk is now one of nine species placed in the genus ''

Buteogallus ''Buteogallus'' is a genus of birds of prey in the family Accipitridae. All members of this genus are essentially neotropical, but the distribution of a single species extends slightly into the extreme southwestern United States. Many of the sp ...

'' that was introduced in 1830 by the French naturalist

René Lesson René-Primevère Lesson (20 March 1794 – 28 April 1849) was a French surgeon, naturalist, ornithologist, and herpetologist. Biography Lesson was born at Rochefort, and entered the Naval Medical School in Rochefort at the age of sixteen. H ...

. The genus name is a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of wordsButeo ''Buteo'' is a genus of medium to fairly large, wide-ranging raptors with a robust body and broad wings. In the Old World, members of this genus are called "buzzards", but " hawk" is used in the New World (Etymology: ''Buteo'' is the Latin na ...

'' introduced in 1779 by

Bernard Germain de Lacépède Bernard-Germain-Étienne de La Ville-sur-Illon, comte de Lacépède or La Cépède (; 26 December 17566 October 1825) was a French naturalist and an active freemason. He is known for his contribution to the Comte de Buffon's great work, the ' ...

for the buzzards and the genus '' Gallus'' introduced in 1760 by

Mathurin Jacques Brisson Mathurin Jacques Brisson (; 30 April 1723 – 23 June 1806) was a French zoologist and natural philosopher. Brisson was born at Fontenay-le-Comte. The earlier part of his life was spent in the pursuit of natural history; his published wo ...

for the junglefowl. The specific epithet ''aequinoctialis'' is from

Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

meaning "equinoctial". The species is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

: no

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 specie ...

are recognized.

Description

The rufous crab hawk is in overall length with a wingspan. Males weigh ; females are heavier and weigh around . Males and females have the same plumage. Adults' head, throat, and neck are sooty black and their back is dark rufous with light rufous edging. Their underparts are rufous with fine dark barring. The tail is black with a white tip and a thin white band. Their eyes are brown and their

cere The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...

and feet are yellow to dusky orange. Immatures have brown to blackish brown upperparts, a grayish tail, and white underparts with dusky streaks.Bierregaard, R. O., G. M. Kirwan, P. F. D. Boesman, and C. J. Sharpe (2020). Rufous Crab Hawk (''Buteogallus aequinoctialis''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.ruchaw1.01 retrieved December 9, 2022

Distribution and habitat

The rufous crab hawk is found on Trinidad and on the South American mainland along the coast from the

Orinoco Delta The Orinoco Delta is a vast river delta of the Orinoco River, located in eastern Venezuela. Location The Orinoco Delta is one of the eight natural regions of Venezuela. It covers the whole of Delta Amacuro State and a few square kilometers of ...

in Venezuela through

the Guianas The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France ...

and into Brazil as far as the southeastern state of Paraná. It primarily inhabits mangroves but also occurs in swamps, wet savanna, and river edges near the coast, all essentially at sea level.

Behavior

Movement

The rufous crab hawk is sedentary and usually seen in pairs.

Feeding

The rufous crab hawk's diet is mostly, and possibly entirely,

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all th ...

s (e.g. ''

Callinectes ''Callinectes'' is a genus of crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirel ...

'' and ''

Ucides ''Ucides'' is a genus of mangrove crabs in the monotypic family Ucididae, containing two species: * '' Ucides cordatus'' (Linnaeus, 1763 Events January–March * January 27 – The seat of colonial administration in the Vice ...

'').https://sta.uwi.edu/fst/lifesciences/sites/default/files/lifesciences/images/Buteogallus_aequinoctialis%20-%20Rufous%20Crab-hawk.pdf It catches them with a short dive from a low perch; it typically takes them to a favored site like a stump to consume them.

Breeding

The rufous crab hawk makes a "sky-dance" display; it is suspected that only the male performs it. Its breeding season varies geographically, for example between February and August in Suriname and apparently from September onward in southeastern Brazil. It makes a nest of twigs lined with leaves in a mangrove or other tree near water. The clutch size is usually one egg though sometimes two are laid. The incubation period and time to fledging are not known.

Vocalization

The rufous crab hawk's call is "a loud rather shrill whistle or laugh...'ke-kee-kee-kee-kew-kew'".

Status

The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

originally assessed the rufous crab hawk as being of Least Concern but since 2013 has classed it as Near Threatened. Its population size is not known and is believed to be decreasing. Ongoing destruction of its mangrove habitat is the principal threat. It varies from rare to fairly common in indifferent parts of its range. Its "restricted habitat makes it highly susceptible locally to any form of deterioration or loss of this habitat" but "this species may tolerate some mangrove disturbance and is found in suburban mangrove swamps in Pará, Brazil."

References

{{Taxonbar, from=Q1268834 rufous crab hawk Birds of the Guianas Birds of Trinidad and Tobago Birds of Brazil Birds of the Atlantic Forest Birds of prey of South America rufous crab hawk rufous crab hawk Taxonomy articles created by Polbot