Original description: Spinites atrogularis Cabanis 1851
Taxonomic history in AOU/AOS Check-list
AOU 1 (1886): Black-chinned Sparrow, Spizella atrigularis
AOU 2 (1895): Black-chinned Sparrow, Spizella atrigularis
AOU 3 (1910): Black-chinned Sparrow, Spizella atrogularis
AOU 4 (1931): Mexican Black-chinned Sparrow, Spizella atrogularis; California Black-chinned Sparrow, Spizella atrogularis cana
AOU 5 (1957): Black-chinned Sparrow, Spizella atrogularis evura, Spizella atrogularis cana, Spizella atrogularis caurina
AOU 6 (1983): Black-chinned Sparrow, Spizella atrogularis
AOU 7 (1998): Black-chinned Sparrow, Spizella atrogularis?
IUCN Conservation Status: Of least concern
Behavior: Even where it is relatively common, the Black-chinned Sparrow can be difficult to see well. Its preference in the breeding season for steep, densely vegetated rocky slopes conceals it from all the most persistent human eyes, and even in winter, when birds can be found at lower elevations, they stay close to heavy cover, disappearing into their fastnesses as soon as they find themselves disturbed or threatened.
Feeding birds shuffle and hop on the ground or perch quietly in grass or the lowest branches of trees and small bushes. Flocks only rarely comprise more than five or six individuals—in many cases probably family groups—though in winter individual Black-chinned Sparrows may join loose assemblages of other desert and mountain sparrows. This species appears to be quite fond of water, a scarce resource over much of its range, and in winter can be seen drinking and bathing in puddles and pools low in mountain canyons in the southwest.
Black-chinned Sparrows are virtually never seen in sustained flight, though migrants can be assumed to engage in such behavior. Birds fleeing humans and other intruders slip into the nearest vegetation, hiding behind leaves and branches and moving to the next bush or upslope in low, direct flight.
Voice: Males begin to sing in late winter or early spring, in northern populations as soon as the breeding grounds are reached. They may sing from the ground, as they feed invisible beneath dense vegetation, but also perch atop short bushes in chaparral; there are occasional records of birds singing as high as 100 feet in treetops
Detailed description and measurements drawn from standard reference works
Adult Spizella atrogularis evura: Tail feathers dusky gray, edged paler gray on outer web. Upper tail coverts and rump gray to olive-gray, the upper tail coverts sometimes with faint darker shaft streaks. Back sandy or clay-brown with blackish streaks; scapulars sandy or clay-brown with pale rusty edges. Primaries and secondaries dull dusky with pale rusty edges on outer web, diffuse whitish edges on inner. Tertials slightly darker slaty with broad deep-brown or rusty edges occupying most of outer web. Greater coverts with dusky center, fairly broad buffy to dull rusty edges; median coverts with dusky center, narrow buffy to dull rusty edges and buffy tips. Marginal coverts of under wing dull whitish. Nape unmarked pale gray.
Under tail coverts, vent, and lower belly whitish with pale gray wash. Upper belly, flanks, and breast rather pale gray. Throat pale to medium gray; upper throat with small diffuse blackish patch in alternate-plumaged male.
Crown medium gray, in some with faint brownish overlay. Forehead medium gray, narrowly marked blackish in alternate-plumaged male. Ear coverts and sides of head medium to pale gray. Lores with black spot in alternate-plumaged male.
Alternate plumage is worn through the entire breeding season; black feathers of throat, forehead, and lore are continually molted from April to September. The prebasic molt of adults begins in August or September, and may still be underway on arrival on the wintering grounds, as late as November.
Slender tarsus and toes dark pinkish brown. Fine, small bill pinkish above and below, with brown tip.
Juvenile Spizella atrogularis evura: Tail feathers dusky gray, edged paler gray on outer web. Upper tail coverts and rump gray to olive-gray, the upper tail coverts with faint darker shaft streaks. Back dull gray-brown with coarse blackish streaks; scapulars sandy or clay-brown with pale rusty edges. Primaries and secondaries dull dusky with pale rusty edges on outer web, diffuse whitish edges on inner. Tertials slightly darker slaty with broad deep-brown or rusty edges occupying most of outer web. Greater coverts dark buffy brown center, broad dull rusty edges; median coverts with dark buffy brown center, narrow dull rusty edges and tips. Marginal coverts of under wing dull whitish. Nape brownish gray.
Under tail coverts, vent, and belly white; flanks and breast dull dark gray with sparse fine darker streaks. Throat pale gray. Crown, ear coverts, and sides of head brownish gray.
Juvenile plumage is worn in the first summer, with the preformative molt beginning as early as June.
Slender tarsus and toes dark pinkish brown. Fine, small bill pinkish or brownish above, pinkish below, with brown tip.
Length 124-140 mm (4.9-5.5 inches)
Wing 60-70 mm (2.4-2.8 inches)
Tail 60-68 mm (2.4-2.7 inches)
W:T 0.94
Mass 12 g
