The male Lark Bunting in his striking black and white breeding plumage stands out from other North American sparrows, especially its more cryptically-colored compatriots on the Great Plains. This breeding plumage is acquired by a complete molt in late winter and early spring. In late summer the male returns to a typical sparrow plumage similar to that of the year-round appearance of the female. In their non-breeding plumage both sexes do have much white on their wing-coverts and some black in the throat (Pyle 1997, Shane 2000)
The breeding season of Lark Buntings is short and probably timed to a peak in insect abundance when nestlings can be stuffed with this high protein food for rapid growth and the shortest time in their vulnerable ground nest for the young birds (Shane 2000).
DISTRIBUTION. During the 1987-1992 field work seasons of the TBBA project, atlasers found most confirmed breeding sites for Lark Buntings in the northern High Plains as well as 14 probable and 9 possible sites north of the 33rd parallel. Other breeding sites occur in the Trans-Pecos and Edwards Plateau regions (see the region map in Lockwood and Freeman ). The map based on North American Breeding Bird Survey (BBS) data from 1994-2003 indicates these buntings breed in the Texas Panhandle at the southern end of their summer range at relative abundances as high as 3-10 individuals per route (Sauer et al. 2007).
Elsewhere most Lark Buntings breed in a swath on the western Great Plains from southern Alberta and Saskatchewan to northeast New Mexico and west Oklahoma at relative abundances as high as 100 buntings per BBS route (Sauer et al. 2007). The species winters from Texas west to southern Arizona and Baja California and south to central Mexico (Howell and Webb 1995, Shane 2000. Lockwood and Freeman 2004).
SEASONAL OCCURRENCE. While Lark Buntings are present somewhere in Texas at any time of the year, they are most common during winter and migration seasons when they are abundant to uncommon in the western half of the state. Spring migrants are present from late March to early May. Breeding occurs in May and June, based on egg dates of May 24 to June 8. Southbound migrants are present from mid-July to late November (Oberholser 1974, Lockwood and Freeman 2004).
BREEDING HABITAT. In Texas Lark Buntings breed from 330-730 m (1100-2400 ft) in dry short-grass prairies (Oberholser 1974). In Oklahoma, atlasers mention short- and mixed-grass prairies and fallow fields with enough plant growth to shelter the nests (Shane 2004). In Colorado about 95% of breeding sites were in grassland habitats (Kingery 1998).
The nest site. selected by the female is usually adjacent to shrub or grass stems and with plant foliage overhead. The nest is built in a depression in the ground with the rim level with or slightly above the ground. The female excavates the depression with her feet while the male gathers grasses and forb stems which are used by the female in construction. In the nest the female usually lats 3-5 (range 2-6) light bluish or greenish eggs, indistinguishable from eggs of Dickcissel (Spiza americana). She incubates the eggs for about 12 days and the young birds leave the nest 8-9 days after hatching while still incapable of flight. They may be fed by their parents near the nest for at least 17 days (Harrison 1979, Shane 2000).
STATUS. Breeding in the Panhandle has apparently increased since Oberholser (1974) described breeding there as rare and irregular The map Oberholser shows numerous summer records in the Panhandle, but very few breeding records in the state. Lockwood and Freeman (2004) describe this species as an uncommon and irregular summer resident in the Panhandle. BBS data from 14 routes during the period 1980-2006 suggest an annual population change of about +5.0% per year, even larger than a trend of about +3.5% in Oklahoma, derived from 16 routes in that state (Sauer et al. 2007). This impressive annual increase is a good omen for the future of this large sparrow as a breeding bird in west Texas. Text by Robert C. Tweit (2008)
Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA.
Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M University Press, College Station.
Shane, T. G. 2004. Lark Bunting (Calamospiza melanocorys). In Oklahoma breeding bird atlas, pp. 410-411 (D. L. Reinking, ed.). University of Oklahoma Press, Norman.