Original description: Haemophila humeralis Cabanis 1851
Taxonomic history in AOU/AOS Check-list
AOU 6 (1983): Black-chested Sparrow, Aimophila humeralis
AOU 7 (1998): Black-chested Sparrow, Aimophila humeralis
IUCN Conservation Status: Of least concern
Behavior: Usually seen in pairs, Black-chested Sparrows feed on the ground, in low vegetation, and, especially, in trees, where they hunt vireo-like along horizontal branches; they have also been observed hovering to take prey from the undersides of leaves. The long tail “may be used as a balancing device as the birds clamber through the vegetation.” Black-chested Sparrows foraging on the ground move with short hops.
Voice: The calls of this species include a decisive ascending tzeep and a soft, prolonged liquid chatter. There is also a stuttering, rising pititit or pitza, given by perched birds and in flight.
Wolf distinguished two song types in the Black-chested Sparrow, one probably given only by the male and the other a “chatter duet.” The first song type is given beginning at dawn, but gradually replaced after sunrise by chatter duets; it comprises “an introductory figure or phrase followed by a trill of varying length.” The introduction varies from a simple downslurred bisyllabic squeak to a series of two or three cardinal-like notes, while the trill tends to be slow and loose, with the bright, cheerful tone of an Eastern Towhee’s song.
In the chatter duet, sung by mated pairs, the male and the female each produce different syllables or phrases; Wolf suspected that the male’s contributions were more variable than the female’s.
Detailed description and measurements drawn from standard reference works
Adult: Tail feathers dusky with grayish brown edges. Upper tail coverts light grayish brown with paler grayish brown tips; rump light grayish brown. Back and scapulars mostly bright rusty with black streaking. Primaries and secondaries dusky with buffy-chestnut edges. Tertials blackish with dull buffy edges. Greater coverts largely blackish, with buffy to chestnut edgings on outer webs and narrow but distinct white tips, forming fine, clear wing bar; median coverts blackish with broad whitish tips and edges, forming clear wing bar. Lesser coverts cinnamon to rusty. Nape unstreaked dark gray, sharply set off from black-streaked rust of back.
Under tail coverts and flanks buffy brown. Vent, belly, and lower breast dull whitish. Upper breast dusky or blackish, fading slightly into dark gray of sides of head. Throat white, separated from broad white jaw stripe by dusky or blackish lateral throat stripe. Ear coverts and lore dusky, gradually darkening to blackish at upper edge of jaw stripe.
Crown dusky, darker towards base of bill. Small triangular white spot above lore.
Tarsus and toes pale dull pink. Thick-based bill black above, bluish below.
Juvenile: Tail feathers dusky with grayish brown edges. Upper tail coverts light grayish brown with paler grayish brown tips; rump light grayish brown. Back and scapulars brown with faint dark brown streaking. Primaries and secondaries dusky with buffy-chestnut edges. Tertials blackish with dull buffy edges. Greater coverts dark brown, with buffy brown edgings on outer webs and narrow buffy tips, forming fine wing bar; median coverts brown with whitish tips and edges, forming narrow wing bar. Lesser coverts brown. Nape buffy gray.
Under tail coverts and flanks buffy brown with darker streaks. Vent, belly, and lower breast dull whitish brown. Upper breast variably buffy to dusky brown, with variably strong dark brown streaks. Throat whitish, very inconspicuously separated from broad whitish jaw stripe by very faint dusky lateral throat stripe. Ear coverts and lore brownish gray.
Crown brownish gray with fine darker streaking. Very small, poorly defined white spot above lore.
Tarsus and toes pale dull pink. Thick-based bill gray above, bluish gray below.
Length 141-160 mm (5.6-6.3 inches)
Wing 59-71 mm (2.3-2.8 inches)
Tail 68-80 mm (2.7-3.1 inches)
Mass 19-26 g