Original description: Fringilla bicolor Townsend 1837
Taxonomic history in AOU/AOS Check-list
AOU 1 (1886): Lark Bunting, Calamospiza melanocorys
AOU 2 (1895): Lark Bunting, Calamospiza melanocorys
AOU 3 (1910): Lark Bunting, Calamospiza melanocorys
AOU 4 (1931): Lark Bunting, Calamospiza melanocorys
AOU 5 (1957): Lark Bunting, Calamospiza melanocorys
AOU 6 (1983): Lark Bunting, Calamospiza melanocorys
AOU 7 (1998): Lark Bunting, Calamospiza melanocorys
IUCN Conservation Status: Of least concern
Behavior: Wintering birds and migrants are occasionally “tame and unsuspicious,” crouching at the observer’s feet or simply continuing to feed with apparent unconcern. On the breeding grounds, however, Lark Buntings can be decidedly shy; more than one early collector found them “very wary and difficult to shoot,” though their gregarious habits somewhat counteracted their shyness: Adolphus Heermann records having taken fourteen individuals at once, and his colleague Caleb Kennerly observed that
“when on the wing they keep very close together, so that a single discharge of small shot will sometimes bring down twenty or thirty.”
Survivors of such encounters fly off fairly low, undulating above the vegetation, landing in the middle distance on wires or bushes, where they perch in dense packs with very little space separating individuals. Unstressed flocks often fly very low through open areas in a rolling, leapfrogging wave, birds at the front of the flock taking off first, only to be overtaken by birds from behind.
Feeding birds hop and walk on the ground beneath sparse vegetation or on open sand and gravel, sometimes scampering briefly in search of animal prey. Usually silent while foraging, they can be surprisingly inconspicuous on the ground, and at least in winter and migration tend to crouch when startled rather than immediately flush. Patient observers can get good views, even in the breeding season, by backing up a step and sitting down quietly as the birds resume their feeding.
Sustained flight in this species is strong and swooping. Song flight, in contrast, is exaggeratedly slow and buoyant. The males emerge from the grass at a sharp angle, and ascend to ten or twenty feet in the air, singing all the while, before tracing a slow lazy circle on deep wing beats and returning to the ground. The slow wing action, in which the wings appear to be beaten in alternation is traditionally described as “butterfly-like” or, more imaginatively, as “a survival of the alternate leg motion of their reptilian ancestors.”
Voice: The distinctive flight call, heard from flocks and individuals at all times of the year, is a hollow, breathy hoot, trailing off at the end; some observers on the southwestern wintering grounds find this note remarkably like one of the calls of the Phainopepla. Adult Lark Buntings are generally quiet when perched, giving an occasional hoot or faint buzz.
The Lark Bunting is justly celebrated for its flight song, first described by John Kirk Townsend:
“While the flock is engaged in feeding, the males are frequently observed to rise suddenly to a considerable height, and poising themselves over their companions, with their wings in constant and rapid motion, they become nearly stationary. In this situation, they pour forth a number of very lively and sweetly modulated notes, and at the expiration of about a minute, descend to the ground, and course about as before.”
Townsend’s field companion Thomas Nuttall called the bird “one of the sweetest songsters of the prairie,” while Joel Asaph Allen compared the Lark Bunting’s performance to that of another gifted singer, the Yellow-breasted Chat; Allen and his collectors “naturally applied to it the cognomen of the ‘Black Chat’.”
As Allen’s comparison aptly suggests, the Lark Bunting’s song comprises three to eight phrases at different pitches and of different tonal qualities, most of them slow but following one on the other without significant pauses. The phrase types, not all of which are sung by every male, include slurred, cardinal-like “sweet,” “cher-wheat,” and “weeta” notes; lower-pitched, chat-like “chug,” “chut,” “toot,” “churt,” and “chew” notes; and trills ranging from low buzzes to high, insect-like tremolos. Songs given by perched birds are usually shorter than those delivered in flight; singing birds often strike a distinctive pose with lowered head, as if scanning the ground beneath their perch.
Detailed description and measurements drawn from standard reference works
Adult female: Tail feathers gray brown. Outermost tail feathers with whitish buffy edge to outer web, others with narrow whitish buffy edges; all but central pair with buffy white tip on inner web, increasing in extent from inner to outermost rectrices (“minor white markings are conspicuous only in fresh plumage and disappear with abrasion, being therefore usually absent in midsummer”). Upper tail coverts, rump, back, scapular, and nape grayish brown with sparse dusky streaks. Primaries and secondaries dull blackish with narrow buffy edges and tips, whiter on outer primaries; edges of central secondaries rusty in basic plumage. Tertials conspicuously edged buffy white on outer web. Outer greater and median coverts mostly buffy, inner greater and median coverts with buffy outer webs. Marginal coverts of under wing blackish.
Under tail coverts, vent, belly, flanks, breast, and throat off-white, buffier in basic plumage; flanks and breast sides with brown tinge. Throat, breast, and flanks with moderate blackish streaks, finest on throat and sometimes coalescing into large, ragged central breast spot. Throat sometimes with black blotches in alternate plumage; separated from creamy or buffy jaw stripe by narrow dark lateral throat stripe. Jaw stripe extends to curve behind brown ear coverts; ear coverts faintly streaked, bordered below by faint, incomplete blackish whisker and above by faint brownish line extending behind eye. Creamy or buffy supercilium poorly defined; continues to nearly base of bill, joining with grayish buffy lore. Crown brown with blackish streaks. Narrow white eye ring, often incomplete behind eye.
Tarsus and toes brown. Heavy, swollen-based bill pale gray above and below, tip dark brown to black.
Adult male, alternate plumage (March to July): Tail feathers black. Outermost tail feathers with white edge to outer web, others with narrow whitish edges; all but central pair with white tip on inner web, increasing in extent from inner to outermost rectrices (“minor white markings are conspicuous only in fresh plumage and disappear with abrasion, being therefore usually absent in midsummer”). Upper tail coverts black with narrow white edges. Rump, back, and nape black or, especially rump and back, grayish black. Scapulars, and sometimes back, with narrow white tips. Primaries and secondaries blackish with narrow white tips, the inner secondaries with narrow irregular white edges on outer web. Tertials conspicuously edged white on outer web. Outer greater coverts whitish, inner greater coverts whitish to buffy with broad blackish centers increasing in width on innermost coverts. Median coverts buffy, the outermost whiter, with inner webs more extensively dark on innermost coverts. mostly or entirely white, inner greater and median coverts with white outer webs. Marginal coverts of under wing blackish.
Under tail coverts black with broad white tips when fresh. Vent, belly, flanks, breast, and throat black, with narrow white tips and edges when fresh. Head black.
Tarsus and toes brown. Heavy, swollen-based bill dark bluish above and below, tip dark brown to black.
Adult male, basic plumage (August to March): Tail feathers black with fairly broad whitish buffy edges; all but central pair with buffy tip on inner web, increasing in extent from inner to outermost rectrices. Upper tail coverts, rump, back, and nape grayish with sparse dusky streaks; scapulars bright buffy with blackish centers. Primaries and secondaries blackish with narrow buffy edges and tips, whiter on outer primaries; edges of central secondaries rusty. Tertials conspicuously edged buffy white on outer web. Outer greater coverts mostly or entirely buffy white, inner greater and median coverts buffy with black centers. Marginal coverts of under wing blackish.
Under tail coverts off-white with bold black centers. Vent, belly, flanks, and breast off-white; flanks and breast sides with browner tinge and heavy dark brown streaks, breast and belly with heavy black streaks and spots, often coalescing into large, ragged central breast spot. Throat black with narrow white feather edges. Buffy jaw stripe extends to curve behind brown ear coverts; ear coverts faintly streaked, bordered below by faint, incomplete blackish whisker and above by faint brownish line extending behind eye. Supercilium very poorly defined or, most often, absent. Crown brown with blackish streaks. Narrow white eye ring, often incomplete behind eye.
Tarsus and toes brown. Heavy, swollen-based bill dark bluish above and below, tip dark brown to black.
Juvenile: Tail feathers brown. Outermost tail feathers with buffy edge to outer web, others with narrow buffy edges; all but central pair with buffy white tip on inner web, increasing in extent from inner to outermost rectrices. Upper tail coverts, rump, back, scapular, and nape buffy brown with fairly coarse dusky streaks. Primaries and secondaries dull blackish with narrow buffy edges and tips. Tertials conspicuously edged buffy on outer web. Outer greater and median coverts buffy, inner greater and median coverts with buffy outer webs. Marginal coverts of under wing dusky.
Under tail coverts, vent, belly, flanks, breast, and throat buffy. Throat, breast, and flanks with well-defined brownish or blackish streaks, finest on throat and sometimes coalescing into large, ragged central breast spot. Throat separated from buffy jaw stripe by narrow dark lateral throat stripe. Jaw stripe extends to curve behind brown ear coverts; ear coverts faintly streaked, bordered below by faint, incomplete blackish whisker and above by faint brownish line extending behind eye. Creamy or buffy supercilium poorly defined; continues to nearly base of bill, joining with buffy lore. Crown buffy with dark brown streaks. Narrow white eye ring, often incomplete behind eye.
Tarsus and toes brown. Heavy, swollen-based bill pale gray-brown above and below, tip dark brown to black.
Length: 140-180 mm (5.5-71. Inches)
Wing: 82-92 mm (3.2-3.6 inches)
Tail: 61-71 mm (2.4-2.8 inches)
W:T 1.28
Mass 38 g
