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“Whether on its winter range or summer breeding ground, McCown’s Longspur is a bird of the plains, of the ‘big sky’ country where the land flattens to the blue haze of mesa or plateau; where distance is the hawk’s flight from a line of craggy ‘breaks’ to the horizon. Amid the features of such a vast landscape it was first collected about 1851, as much by accident as by design. ‘I fired at a flock of Shore Larks,’ wrote Capt. John P. McCown, U.S. (1851), ‘and found this bird among the killed.’”
So wrote Herbert Krause (1968), in opening his life history of the McCown’s Longspur in A. C. Bent’s series, which preceded this one. Characteristic of the shortgrass prairie, the McCown’s Longspur favors the open wind-swept plains and sparse vegetation provided by native shortgrass prairie, or structurally similar habitats such as overgrazed pastures. In its striking Aerial Display, the male flutters upward to a height of about 10 m and then descends, teetering on outstretched wings held back to display the vivid white lining, with its white-and-black “T”-patterned tail fanned, and issuing a tinkling, warbling song.
These longspurs arrive on their breeding grounds in the northwestern fringe of the Great Plains and the southern edge of the Canadian Prairie Provinces in April, and establish territories by means of this Aerial Display. Females build compact nests in the ground beside cactus pads, clumps of grass, or beneath shrubs. Females lay two to five eggs and incubate them for about 12 days; both parents feed and brood nestlings. Young fledge at about 10 days. Longspurs begin flocking in August, and amass huge flocks en route to wintering grounds in the southwestern United States, Texas, and northern Mexico.
Although this is one of the few grassland species that may actually benefit from grazing, other disruptions of habitat—plowing, use of pesticides, and control of grassland fires that maintain shortgrass prairie—have reduced its numbers and its distribution.
Some aspects of the biology and natural history of McCown’s Longspurs have received study and are reasonably well-known, including growth and development of young (Mickey 1943), habitat associations (Krause 1968, Creighton and Baldwin 1974, Grzybowski 1982, Smith et al. 2004), diet and foraging behavior (Baldwin and Creighton 1972, Maher 1974), breeding behavior (DuBois 1923, 1935; Mickey 1943, Krause 1968), nest-site selection and reproductive success (Felske 1971, With and Webb 1993, With 1994), territoriality (Giezentanner 1970, Felske 1971) and breeding density (Giezentanner 1970, Porter and Ryder 1974, Greer and Anderson 1989).
Other aspects of the life history of this species remain much less well know. There have been few attempts to investigate the impact of human disturbances on longspurs, for example, including pesticide use (McEwen and Ells 1975), land-management practices (Ryder 1980, With 1994, Smith et al. 2004), and physiological stress (Lynn et al. 2003). Such information is crucial given the substantial declines this species has seen in its historical range and population levels. No formal demographic analysis has been performed to evaluate population viability or uncover factors contributing to ongoing declines. Such efforts will be hampered by a lack of data on dispersal and demographic rates, especially survivorship. Little is known about this species’ migratory ecology.