Appearance

Chachalacas (Ortalis) are small cracids. All species have long tails, fairly long and stout tarsi, long necks, and loud raucous calls. West Mexican Chachalaca is a relatively large chachalaca. The upperparts and upper breast generally are grayish brown, but the head and upper neck are grayer. The lower breast and belly are white, with cinnamon undertail coverts. The tips of the tail feathers are broadly tipped with creamy buff. The sexes are similar.

Rufous-bellied Chachalaca (Ortalis wagleri) is a similar species that occurs in western Mexico from southern Sonora to extreme northern Jalisco, and so apparently replaces West Mexican Chachalaca very abruptly. The most distinctive feature of Rufous-bellied Chachalaca is its rufous belly and rufous tips to the rectrices. The status of these two species is unclear, as some hybrids or intergrades have been reported. In areas where the two species approach one another, West Mexican Chachalaca occurs at higher elevations in more humid forests.

White-bellied Chachalaca (Ortalis leucogastra) overlaps narrowly with West Mexican Chachalaca in Chiapas. White-bellied Chachalaca is smaller than West Mexican Chachalaca, with broader and whiter tips to the rectrices, whitish (not cinnamon) undertail coverts, and usually occurs at lower elevations.

Plain Chachalacas (Ortalis vetula) replaces West Mexican Chachalaca on the Atlantic Slope of eastern Mexico, but both species overlap in a small area near Pijijiapan in Chiapas. Plain Chachalacas are slightly smaller, with a buffy brown belly.

The following description is based on Ridgway and Friedmann (1946) and

Adult: Sexes similar. Forecrown, crown and nape dull brownish gray. Upperparts otherwise pale brownish olive. Rectrices slightly grayer with broad pale tips, pale to dark ochraceous buff. Breast grayish olive. Belly whitish, washed to a greater or lesser degree with pale ochraceous buff, this wash stronger on the flanks and tibial feathers. Undertail coverts ochraceous buff.

Juvenile: Generally similar to the adult; rectrices more pointed.

Undescribed for West Mexican Chachalaca. Presumably follows the complex basic molt strategy, as does Plain Chachalaca (Ortalis vetula) (Pyle 2008).

Iris: hazel brown

Bare orbital and gular skin: carmine

Bill: pale gray

Tarsi and toes: ashy gray

Bare parts color data from Ridgway and Friedmann (1946).

Total length: 58.5-68.5 cm (Howell and Webb 1995)

Linear measurements (from Ridgway and Friedmann 1946):

male (n = 15)

wing length: mean 248.4 mm (range 235-263 mm)

tail length: mean 283.2 mm (range 263-310 mm)

bill length (exposed culmen): mean 29.8 mm (range 26-33 mm)

tarsus length: mean 71.5 mm (range 68-77 mm)

female (n = 6)

wing length: mean 244 mm (range 229-263 mm)

tail length: mean 276 mm (range 247-304 mm)

bill length (exposed culmen): mean 70.1 mm (range 66-72 mm)

tarsus length: mean 70.1 mm (range 66-72 mm)

Mass: 760 g (n = 1, male; Dunning 2008)