Black-crowned Antpitta is a rotund, short-tailed, rather long-legged terrestrial bird. The male has a sooty black crown with rufous cheek patch, a large, strong, silvery gray bill, brown back with dark streaking, brown wings with buff spotting on the tips of the coverts and black and white "scalloped" underparts. The female is similarly plumaged but has buffier colored underparts.
Its striking appearance, however, doesn't make it any easier to see in the dim understory of the dense, primary rainforests where it occurs.
The striking black and white scalloped underparts, black crown, and plump, tail-less appearance make Black-crowned Antpitta nearly unmistakable. It shares much of its range and habitat with another short-tailed, black-headed terrestrial bird, Black-headed Antthrush (Formicarius nigricapillus), but the antthrush lacks boldly scalloped underparts and walks with its tail cocked up like a rail or sa mall chicken, instead of hopping as does the antpitta.
Black-crowned Antpitta also occurs with the similarly shaped Streak-chested Antpitta (Hylopezus perspicillatus), Thicket Antpitta (Hylopezus dives), and Scaled Antpitta (Grallaria guatimalensis), but all of these have gray on the head and plain or streaked underparts.
The following description is based on Wetmore (1972), and refers to nominate michleri; see also Geographic Variation:
Adult male: Crown and nape black. Lores white mixed with chestnut. Sides of the head chestnut. Back, rump, and uppertail coverts olive brown; feathers of the back edged with black, producing indistinct streaks. Wings chestnut brown, wing coverts with narrow spots of white or buff, bordered with black. Tertials with a terminal spot of buff. Outer webs of primaries cinnamon. Chin and and throat black, mixed with narrow shaft streaks or spots of white and chestnut. Breast and belly white, heavily barred with black. Flanks light brown. Undertail coverts buff to tawny, feathers with a subterminal circular black line.
Adult female: Resembles the male but throat rufous with black scalloping, and less distinct black markings on the underparts.
Immature: Sooty crown, face is brown and rufous, back faintly barred with black and light brown, wing bars more prominent, and fainter scalloping on underparts (Stiles and Skutch 1989).
Iris: dark brown.
Bill: maxilla black with ivory white tomia and tip; mandible ivory white.
Tarsi and toes: gray.
Bare parts color data from Wetmore (1972) and Robbins et al. (1985).
Total length: 18 cm (Garrigues and Dean 2007), 18-19 cm (Krabbe and Schulenberg 2003), 19 cm (Stiles and Skutch 1989).
Linear measurements (from Wetmore 1972):
male (n = 10)
wing length: mean 96.8 mm (range 92.3-99.8 mm)
tail length: mean 33.0 mm (range 31.5-36.3 mm)
bill length (culmen from base): mean 30.4 mm (range 28.9-31.7 mm)
tarsus length: mean 52.0 mm (range 48.7-54.2 mm)
female (n = 10)
wing length: mean 95.6 mm (range 93.4-99.4 mm)
tail length: mean 33.2 mm (range 32.0-35.0 mm)
bill length (culmen from base): mean 29.1 mm (range 27.2-30.8 mm; n = 9)
tarsus length: mean 50.3 mm (range 48.1-52.2 mm)
Mass: 99 g (n = 1, male, michleri; Wetmore 1972); 109.3 g (n = 1, sex undetermined; Karr 1971); 110 g (Stiles and Skutch 1989).