All species › Birds of prey › Kites, Old World vultures, eagles and hawks › Grey-backed Hawk
Grey-backed Hawk | Pseudastur occidentalis
Grijsrugbuizerd | Gavilán dorsigrís | Gavião-de-costas-cinzentas
The Grey-backed Hawk is a grey-and-white forest hawk found only in western Ecuador and the far north-west of Peru. It depends on forest and has become scarce through the large-scale deforestation of this region. It is one of the characteristic species of the Tumbes region.
Voice
A hoarse, descending scream, keeeer, often in flight.
Recording: Rainforest Connection — CC BY-NC-SA 4.0 · xeno-canto
Identification
45–51 cm; the female is larger than the male. The adult is dark slate grey on the back and wings, with a white head streaked grey on the crown and hindneck. The underparts are white. The tail is white with a broad black subterminal band. The cere and legs are yellow to orange-yellow. In flight the underwing coverts are white and the flight feathers grey with dark tips. Juveniles have more streaking on the head and breast and a browner back.
Confusion species
White Hawk Pseudastur albicollis is largely white, with black in the wings, and has a black tail with a broad white band; in the guide area it lives mainly north and east of the range of Grey-backed Hawk. Semiplumbeous Hawk Leucopternis semiplumbeus is smaller, with a plain grey head and orange cere and legs. Short-tailed Hawk Buteo brachyurus has a dark head and a grey, barred tail.
Habitat
Humid and semi-humid forest, deciduous dry forest, forest edges and larger forest fragments. From sea level into the lower mountains, mainly below about 1500 m, locally higher. It soars over the forest and hunts from a perch for reptiles, small mammals, birds and large insects. The nest is a stick nest high in a tree.
Where the bird is most at home, classified by the vegetation units of the Andes and the west coast.
Range and movements
In Ecuador in the western lowlands and on the western foothills of the Andes, from Esmeraldas to El Oro and Loja. In Peru only in the far north-west, mainly in Tumbes. Not in Colombia or Bolivia. The entire range lies within the guide area.
- Resident
- dark = core range, pale = thinly spread
How and when to look
Search in the larger forest areas of western Ecuador and in the forest of Tumbes, at a viewpoint over the canopy in the morning, when the birds soar over the forest.
Conservation status
Vulnerable. The population is small and fragmented; most of the original forest within its range has been cleared or converted to farmland.
Scientific name
Pseudastur occidentalis | (Salvin, 1876) (GBIF: Leucopternis occidentalis)
Salvin described the species in 1876 as Leucopternis occidentalis; because it was later moved to another genus, the author and year stand in brackets. The genus Pseudastur was introduced in 1849 by Gray. The genus name combines Greek pseudo-, 'false', with Latin astur, 'hawk'. The species name is Latin occidentalis, 'western', after its range in western Ecuador and Peru. The specimen the first description was based on came from Western Ecuador.