The grey-backed hawk (''Pseudastur occidentalis'') is an

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

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 ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

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 widespre ...

, 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 ...

. It is found in

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

and far northern

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

.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

Taxonomy and systematics

The grey-backed hawk was traditionally placed in genus ''Leucopternis'' but following a 2006 paper, taxonomists moved it and two other species to genus ''Pseudastur''.Amaral, F.S.R., Miller, M.J., Silveira, L.F., Bermingham, E. and Wajntal, A. (2006). Polyphyly of the hawk genera Leucopternis and Buteogallus (Aves, Accipitridae): multiple habitat shifts during the Neotropical buteonine diversification. BMC Evolutionary Biology. 6(10): 1–21.Clements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of birds of the world: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved November 10, 2022HBW and BirdLife International (2022) Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6b. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6b_Jul22.zip retrieved December 5, 2022 The grey-backed hawk 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 "unispec ...

Description

The grey-backed hawk is long with a wingspan. One female weighed . Females are about 10% larger than males and both sexes have the same plumage. Adults have a gray and white streaked head, nape, and mantle. They have blackish gray upperparts and a mostly white tail with a wide black band near the end. Their eye is dark brown, 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, ...

gray, and their legs and feet pale yellow. Immatures have brownish gray upperparts, a dusky-striped nape, and gray spots on the breast.Bierregaard, R. O., G. M. Kirwan, D. A. Christie, and P. F. D. Boesman (2020). Gray-backed Hawk (''Pseudastur occidentalis''), 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.gybhaw2.01 retrieved December 10, 2022

Distribution and habitat

The grey-backed hawk is found locally in western Ecuador between southern Esmeraldas and Loja provinces and slightly into Peru's

Department of Tumbes Tumbes () is a coastal department and region in northwestern Peru bordering Ecuador. Due to the region's location near the Equator it has a warm climate, with beaches that are considered among the finest in Peru. Despite its small area, the reg ...

. It inhabits subtropical and tropical

semi-deciduous Semi-deciduous or semi-evergreen is a botanical term which refers to plants that lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and sub-tropical woody spec ...

and evergreen forest,

cloudforest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...

, and

secondary forest A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. ...

. It prefers moist areas and is often found in steep ravines. In elevation it mostly ranges between but occurs as high as .

Behavior

Movement

The grey-backed hawk is sedentary.

Feeding

The grey-backed hawk's hunting method and diet are not well defined. It has been recorded hunting over streams and croplands and sometimes up to four will hunt together. Its diet includes reptiles, amphibians, crabs, rodents, birds, and large insects.

Breeding

The grey-backed hawk appears to nest at any time of the year but its breeding activity appears to be concentrated between December and April, the local rainy season. Pairs make display flights. Nothing else is known about its breeding biology.

Vocalization

During the grey-backed hawk's display flights, one bird will make a "drawn-out screeching ''keeeaaarr-keeeaaarr...'' (which rises in central portion) or, alternatively, a high-pitched ''kéééoooowww''".

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 grey-backed hawk as Threatened but since 1994 has classed it as Endangered. It has a small range and its estimated population of 250 to 1000 mature individuals is believed to be decreasing. The population is fragmented. Its forest habitat is undergoing continuing destruction for timber and agriculture. Even some nominally protected areas are illegally logged and cleared. The "combination of clearance for agriculture and timber supplies and intense grazing (by goats and cattle) in understorey has made he westernEcuadorian forests one of heworld’s most threatened ecosystems."

References

{{Taxonbar, from=Q1262047

grey-backed hawk The grey-backed hawk (''Pseudastur occidentalis'') is an Endangered species (IUCN status), Endangered species of bird of prey in subfamily Accipitrinae, the "true" hawks, of family Accipitridae. It is found in Ecuador and far northern Peru.Rems ...

Birds of Ecuador

Taxonomy articles created by Polbot