Appearance

Tinamous are pudgy, terrestrial birds with very short tails and rounded wings. The three species of Nothocercus are medium sized tinamous of humid montane forests. Highland Tinamou is a dark reddish brown tinamou; the upperparts are finely black vermiculated with black, and the underparts are cinnamon brown. The crown and sides of the head are black or blackish, while the throat is ochraceous to rufous. The sexes are similar in appearance.

Highland Tinamou is sympatric with few other species of tinamou. Tawny-breasted Tinamou (Nothocercus julius) overlaps with Highland Tinamou in the Andes from Venezuela to Peru, but is found at higher elevations, and has a white throat and dull chestnut to sooty brown (not gray or blackish) head. There is no geographic overlap with Hooded Tinamou (Nothocercus nigrocapillus), which replaces Highland Tinamou south of the Río Marañón in northern Peru; Hooded Tinamou also has a white throat. Gray Tinamou (Tinamus tao) is larger and gray, not brown. Highland Tinamou typically occurs higher in elevation than other species in its geographic range.

The following description is based on Blake (1977), and refers to nominate bonapartei; see also Geographic Variation:

Adult: Sexes alike. Crown and sides of head black or blackish, becoming dark brown on the nape and upperparts, which ere very finely vermiculated with black. Wing coverts slightly paler brown and more or less profusely spotted with buff and black. Remiges dusky, mottled and barred with cinnamon and black, especially on the outer webs. Throat ochraceous or rufous. Breast and abdomen reddish brown, paler on the belly and tibial feathers, which are obscurely barred. Flanks darker brown, the feathers with pale tips and black subterminal spots or bars.

Immature: Similar to the adult (Blake 1977); one immature from Colombia differs in having a dingier (not buffy) throat, somewhat darker and less rufescent breast, and much finer barring on the lower belly and flanks. Additionally, some feathers of the forecrown and postocular region are minutely tipped with white (Blake 1955).

Chick: Head and neck dark gray, with small white spots on nape; back dark reddish brown, finely vermiculated with black; chin with only a small whitish area; underparts pale rufous, paler on belly and undertail coverts (McKay 1980).

Undescribed?

Iris: dark brown

Bill: maxilla black; mandible black, whitish at base

Tarsi and toes: plumbeous

Bare parts color from Wetmore (1965).

Total length: 35.5-38 cm (Ridgely and Greenfield 2001b), 38 cm (Stiles and Skutch 1989), Hilty and Brown (1986), 38-41 cm (Hilty 2003)

Linear measurements (from Blake 1977):

frantzii, male:

wing length (flat): mean 212.5 mm (range 205-220 mm, n = 6)

bill length (culmen from base): mean 33 mm (range 31.2-35.4 mm, n = 8)

tarsus length: mean 69 mm (range 66.6-71.3 mm, n = 8)

frantzii, female:

wing length (flat): mean 226.8 mm (range 221-241 mm, n = 6)

bill length (culmen from base): mean 34.5 mm (range 32.7-36.8 mm, n = 10)

tarsus length: mean 72.5 mm (range 68.1-74.6 mm, n = 10)

intercedens, male (n = 8):

wing length (flat): mean 209.8 mm (range 200-218 mm)

bill length (exposed culmen): mean 29.5 mm (range 28-31 mm)

intercedens, female (n = 7):

wing length (flat): mean 213.4 mm (range 203-224 mm)

bill length (exposed culmen): mean 29.6 mm (range 25-33 mm)

bonapartei, male (n = 7):

wing length (flat): mean 215.2 mm (range 207-226 mm)

bill length (exposed culmen): mean 28.8 mm (range 26-31 mm)

bonapartei, female (n = 5):

wing length (flat): mean 222 mm (range 218-244 mm)

bill length (exposed culmen): mean 31.7 mm (range 30-33 mm)

discrepans, female (holotype; n = 1):

wing length (flat): 228 mm

bill length (exposed culmen) 32 mm

tarrsus length: ca 65 mm

plumbeiceps, male (n = 8):

wing length (flat): mean 204.5 (range 196-214 mm)

bill length (exposed culmen): mean 29 mm (range 26-32 mm)

plumbeiceps, female (n = 3):

wing length (flat): mean 218.3 mm (range 216-222 mm)

bill length (exposed culmen): mean 30.4 mm (range 26-38 mm)

Mass: Published data on mass of Highland Tinamou encompass a surprisingly wide range of values, for which there is not a ready explanation: male 500 g (n = 1), female 455 g (n = 1) (Panama, Hartman 1955); male, mean 844 ± 18.1 g (n = 4), female 1050 g (n = 1) (Panama, Hartman 1961); female, 728 g (n = 1, laying, with fully formed egg in oviduct, Colombia; Miller 1963)