About Leucopternis occidentalis Salvin, 1876
The grey-backed hawk (scientific name Leucopternis occidentalis Salvin, 1876) measures 45 to 52 cm (18 to 20 in) in length, with a wingspan of 104 to 116 cm (41 to 46 in). One recorded female specimen weighed 660 g (23 oz). Females are approximately 10% larger than males, and both sexes share identical plumage patterns. Adult grey-backed hawks have gray and white streaking on the head, nape, and mantle, blackish gray upperparts, and a mostly white tail with a broad black band near the tip. They have dark brown eyes, a gray cere, and pale yellow legs and feet. Immature individuals have brownish gray upperparts, a dusky-striped nape, and gray spots on the breast. This species is found locally in western Ecuador, ranging between southern Esmeraldas and Loja provinces, and extends slightly into the Department of Tumbes in Peru. It inhabits subtropical and tropical semi-deciduous forest, evergreen forest, cloudforest, and secondary forest. It favors moist locations and is often found in steep ravines. Most individuals occur between 100 and 1,400 m (330 and 4,600 ft) in elevation, though the species can be found as high as 2,900 m (9,500 ft).
