Appearance

Heliodoxa are medium large, heavy bodied hummingbirds with stout black bills that are more or less straight. The feathers of the forecrown extend onto the base of the maxilla, giving a somewhat tapered shape to the head. Most species are montane, and are sexually dimorphic. Most species of brilliant are mostly glittering green, but Fawn-breasted Brilliant is green only on the upperparts. The underparts of Fawn-breasted are primarily cinnamon buff, with green speckling on the throat and breast. Males have a small patch of pink on the center of the throat, but this usually is lacking in females.

Fawn-breasted Brilliant is distinctive within its range, and is unlikely to be confused with any other species: no other similarly sized hummingbird is green above and buffy below. Chestnut-breasted Coronet (Boissonneaua matthewsii) is deeper rufous below, with a green throat, and a shorter bill.

A medium large hummingbird with a long, heavy, straight bill. The following description is based on Hinkelmann (1999):

Adult male: Upperparts generally shining bronzy green; wing coverts more coppery. Rectrices coppery green and slightly forked. Chin green; center of lower throat rosy violet. Remaining underparts cinnamon buff, with scattered green disks on the throat and flanks.

Adult female: Similar to male, but chin cinnamon buff (not green), and usually lacks the rosy throat patch.

Iris: brown, dark brown, negro

Bill: black

Toes: brown, rosado

Bare parts color data from Miller (1963) and from specimens in the Field Museum of Natural History.

Total length: 11.2 cm (Hilty and Brown 1986); 10 cm (female), 11 cm (male) (Ridgely and Greenfield 2001b)

Linear measurements: 

bill length, male: mean 2.24 mm ± .08 mm (n = 5; Colwell 2000)

bill length, female: mean 2.34 mm ± 0.10 mm (n = 6; Colwell 2000)

Mass: male, mean 8.0 g ± 0.4 g (n = 5; Colwell 2000); female, mean 7.6 g ± 0.3 g (n = 6; Colwell 2000)

  female, 7.5 g (n = 1, rubinoides; Echeverry-Galvis et al. 2006)

 male, mean 7.9 g (range 7.9-8.1 g, n = 3, aequatorialis; Miller 1963); female, mean 7.7 g (range 7.3-8.0 g, n = 3, aequatorialis; Miller 1963)

 male, 6.0 g (n = 1, cervinigularis; Parker and O'Neill 1980); female, 7.0 g (n =  1; cervinigularis; Parker and O'Neill 1980)

 mean (sexes combined?), 7.74 g (n = 8; Brown and Bowers 1985)