Medium-sized cathartid vulture common to large, undisturbed tracts of primary forest in northern and central South America. The plumage of Greater Yellow-headed Vulture is blackish overall, with pale gray undersides to the outer primaries and secondaries, but dark undersides to the inner primaries. The head and upper neck are bare and brightly colored, with a bright yellow head and deep blue crown and lores. Greater Yellow-headed Vulture has longer rectrices than the smaller, sympatric Lesser Yellow-headed Vulture (Cathartes burrovianus), and its wing coverts have a more obvious green to purple iridescent sheen.
Greater Yellow-headed Vulture was not recognized as a distinct species until Wetmore (1964) clarified the differences between it and the more widespread Lesser Yellow-headed Vulture (Cathartes burrovianus). The two species can be distinguished in the field by the deeper yellow- to orange head of Lesser Yellow-headed Vulture and the absence of yellow on its throat. Lesser Yellow-headed also has pale undersides to all of the remiges, whereas Greater Yellow-headed has dark inner primaries, contrasting with the pale undersides to the secondaries and outer primaries. The upper surface of the wing of Lesser Yellow-headed has white or whitish shafts to the outer primaries; Greater Yellow-headed lacks these pale shafts. The species also occupy different habitats and have different flight profiles, with Lesser Yellow-headed Vulture preferring open savanna and wetland habitats, where it often forages very low to the ground, while Greater Yellow-headed Vulture forages almost exclusively restricted to undisturbed primary forest, where it typically soars above the canopy (Amadon 1977, Hiilty and Brown 1986, Graves 2016).
May also be confused with Turkey Vulture (Cathartes aura). Greater Yellow-headed Vulture lacks the red head of the Turkey Vulture , has broader wings and blacker plumage, and the undersurface of the outer primaries is dark, with only the outer primaries and the secondaries having pale undersides. In flight Greater Yellow-headed Vulture holds its wings nearly level, whereas both Turkey and Lesser Yellow-headed vultures fly with wings held in a slight dihedral (V-shape) (Hilty and Brown 1986, Sick, 1993).
Adult: Sexes similar. Head and upper neck bare, and brightly colored; see Bare Parts. Plumage generally deep black, with an iridescent sheen that typically is greenish, but that can appear dull bluish from some angles. Undersurfaces of remiges and rectrices brownish gray, except for darker (blackish) inner primaries.
No data exists for Greater Yellow-headed Vulture.; probably follows the Simple Basic Molt strategy. Presumably also follows a stepwise pattern of wing molt, as in the other species of cathartid vultures (Pyle 2008, Howell 2010).
Head and upper neck: Facial skin generally vibrant lemon yellow to chrome yellow, from the base of the bill posterior to the auricular region, and down to the throat. Crown and nape flesh, pale grayish purple, or pale pinkish purple, and studded with white, pinkish white, or pale pink caruncles; sides of the crown behind the eye are slate blue, shading to pinkish purple distally. Patches of grayish skin, covered with short black filoplumes, on the face anterior to the eye, and from the lower eyelid to the ear opening in the auricular region.
Bill: flesh (Wetmore 1964), ivory
Bare parts color data from Wetmore (1964) and Graves (2016).
Total length: 63.5-75 cm (Blake 1977), 74-81 cm (Hilty and Brown 1986)
Linear Measurements (from Wetmore 1964) unless otherwise specified):
wing length: mean 505.7 mm (range 488–530 mm, n = 8)
tail length: mean 264.4 mm (range 252–275 mm, n = 9)
bill length (culmen from cere): mean 24.6 mm (range 23.9–25.5 mm, n = 8))
tarsus length: mean 70.7 (range 69.3–72.5 mm, n = 9)
width of central rectrix: mean 63.4 mm (range 59-70 mm, n = 9)
wing length: mean 511 mm (range 510–512 mm, n = 2)
tail length: mean 279 mm (range 272–285, n = 3)
bill length (culmen from cere): mean 24.6 mm (range 23.9–25.5 mm, n = 3)
tarsus length: mean 70.9 mm (range 69.3–72.5 mm, n = 3)
width of central rectrix: mean 64.3 mm (range 60-67 mm, n = 3)
Mass: mean 1488 g (range 1300-1750 g, n = 11, sexes combined; Marín et al. 1992, Graves 2016)