Calamospiza melanocorys

BREEDING: Plains, prairies, meadows and sagebrush (AOU 1998). Use grasslands of low to moderate height with high vegetative cover and 10-15% bare ground (Wiens 1970, Creighton 1974), often with a superstory component such as shrubs (Baldwin et al. 1969, With and Webb 1993). Shrubs are especially important in savanna and sagebrush (ARTEMISIA) habitats (Woolfolk 1945). Shortgrass prairie, mixed-grass prairie, and shrubsteppe habitats support populations, as do weedy fallow croplands, minimum-tillage croplands, planted cover (e.g., Conservation Reserve Program [CRP] fields and Permanent Cover Program [PCP] fields), legume haylands, and pastures planted to either native or tame grasses (Cameron 1908; Shane 1972, in prep.; Wiens 1973; Creighton 1974; Maher 1974; Porter and Ryder 1974; Stewart 1975; Johnsgard 1980; Pleszczynska and Hansell 1980; Johnson 1981; Kantrud 1981; Kantrud and Kologiski 1983; Dunn 1986; Johnson and Schwartz 1993a,b; Lokemoen and Beiser 1997; McMaster and Davis 1998; Duncan and Davis in press). Rotenberry and Wiens (1980) found that abundance in parts of Colorado, Kansas, Montana, Nebraska, Oklahoma, South Dakota, Texas, and Wyoming was correlated positively with litter depth. BBS data indicated that Lark Buntings preferred areas dominated by wheatgrass (AGROPYRON SPP.), blue grama (BOUTELOUA GRACILIS), needle-and-thread (STIPA COMATA), and big sagebrush (ARTEMISIA TRIDENTATA) (Shane in prep.).

Nests on ground, in grass, under or near clump of vegetation or shrub. Nest usually in a depression. In portions of Colorado, Kansas, Minnesota, Nebraska, North Dakota, Oklahoma, South Dakota, and Texas, nested in mixed-grass and shortgrass areas and areas dominated by sagebrush (ARTEMISIA); they also used taller grass areas with scattered shrubs, weedy edges, retired cropland, and alfalfa (MEDICAGO SATIVA) or clover (TRIFOLIUM) fields (Johnsgard 1979). Often build nests under protective vegetation, including forbs, tall grasses, low shrubs, plains prickly pear cactus (OPUNTIA POLYACANTHA), and yucca (YUCCA GLAUCA) (Whittle 1922; Woolfolk 1945; Baumgarten 1968; Baldwin et al. 1969; Creighton 1971; Shane 1972, in prep.; Stewart 1975; Wilson 1976; Pleszczynska 1977; Johnsgard 1979). Vegetative cover may provide protection from inclement weather and from depredation (Woolfolk 1945, Baumgarten 1968, Baldwin et al. 1969, Strong 1971, Creighton 1974, Pleszczynka 1977, With and Webb 1993), as well as provide open views in one or more directions (Baldwin et al. 1969, Shane 1972, Wilson 1976).

The presence of protective cover may be a major factor in reproductive success (Strong 1971, Pleszczynska 1977). In Kansas, oriented nests adjacent to protective vegetation that allowed access to morning sunlight, adequate ventilation, and afternoon shade (Shane 1974). In Colorado shortgrass pasture, the majority of nests were placed on the northern side of vegetation (With and Webb 1993). In other studies, nests were placed on the east or southeast side of protective vegetation (Baldwin et al. 1969, Creighton 1971, Pleszczynska 1977).

Time of season may influence selection of nesting habitat. In Kansas, used stubble fields for nesting during the early part of the breeding season, and later nested in native grassland on hillsides with sparser vegetation (Wilson 1976).

Mean height of vegetation around ground nests in Colorado (Baldwin et al. 1969), Kansas (Shane 1972), and Utah (Johnson 1981) ranged from 15 to 28 centimeters. In sand-sagebrush (ARTEMISIA FILIFOLIA) grasslands in Kansas, areas in which nests were found had fewer and shorter sand sagebrush plants and had higher percent forb cover (mean of 48.2%) than areas where nests were not present (Shane 1972). Successful nests (those with young present 6 days after hatching) were adjacent to tall (mean of 30.6 centimeters) overall vegetation and tall (mean of 41.9 centimeters) forbs.

NON-BREEDING: in migration and winter also in cultivated lands, brushy areas and desert (AOU 1998).

Territory size in northcentral Colorado was 0.5-1.1 hectares (Wiens 1970, 1971; Finch et al. 1987). In South Dakota, territory size averaged about 0.2 hectares in idle mixed-grass and alfalfa fields (Pleszczynska 1977). However, territory size may be difficult to measure because unmated males will display within other males' territories (Finch et al. 1987).

Breeding begins mid- to late May (Harrison 1978). Clutch size is 3-7 (usually 4-5). Incubation lasts 12 days (Terres 1980). Nestlings are altricial and downy; young are tended by both adults. Gregarious; may nest only 30 meters apart (Terres 1980).