McCown’s Longspur (Calcarius mccownii) Winter only   NMPIF level: Species Conservation Concern, Level 1 (SC1) NMPIF assessment score: 17  NM stewardship responsibility: Moderate National PIF status: Watch List New Mexico BCRs: 18, 34, 35, (16) (most in 18 and 35; all winter only) Primary Wintering Habitat(s): Chihuahuan Desert Grasslands, Agricultural Other habitats used: Plains-Mesa Grassland   Summary of Concern McCown’s Longspur is a prairie species of the northern Great Plains, wintering in the southwestern United States and portions of northern Mexico. Populations have been declining due to loss of grassland habitat in breeding and wintering areas. The small winter range of this species includes most of New Mexico.    Associated Wintering Species Burrowing Owl, Horned Lark   Distribution McCown’s Longspur has a small breeding range in the northwest Great Plains and the southern prairie provinces of Canada. It winters from western Oklahoma to southeast Arizona, and south into northern Mexico on the Plateau from northern Sonora and Chihuahua to northern Durango.  In New Mexico, McCown’s Longspur may be present in winter nearly statewide, but is more common in the southern two-thirds of the state, particularly on the eastern plains and in the Animas Valley (With 1994, Parmeter et al. 2002).   Ecology and Habitat Requirements McCown’s Longspur occupies native shortgrass prairie, or structurally similar habitats such as overgrazed pastures, plowed fields, and dry lake beds (With 1994). In western Texas, McCown’s Longspurs were most abundant on lightly grazed pastures. Vegetation was described as a Bouteloua-Buchloe matrix interspersed with other grass species and some low shrubs, with vegetation height <0.5 m (Grzybowski 1982). Grass in preferred habitat often has a "lawn-like" look. In New Mexico, McCown’s Longspur has been observed in heavily grazed habitat with considerable bare ground.  Beginning in August, Longspurs amass huge flocks en route to wintering grounds in the southwestern United States and northern Mexico. Birds arrive in New Mexico from late September through October, and remain until late February or March. Use of particular wintering sites may vary from year to year (With 1994).    Conservation Status Species Assessment   DISTRIBUTION  5  THREATS  3  GLOBAL POPULATION SIZE  3  LOCAL POPULATION TREND  3  IMPORTANCE OF NEW MEXICO TO BREEDING (WINTERING)  3  COMBINED SCORE  17 McCown’s Longspur is a Species Conservation Concern, Level 1 wintering species for New Mexico, with a total assessment score of 17. McCown’s Longspur is a national PIF Watch List Species. At the continental level, it receives maximum PIF vulnerability scores of 5 for its very small breeding and non-breeding distributions. McCown’s Longspur is a U.S. Fish and Wildlife Service (2002) national Bird of Conservation Concern.    Population Size PIF estimates a species population of 1.1 million. Size of the wintering population in New Mexico is unknown, and may be variable. Ligon (1961) noted that numbers appeared far lower than suggested by historical accounts.   Population Trend No data are available for winter populations in New Mexico. BBS data for 1966-2004 show significant long-term declines in the western region (annual trend = -9.6, p = 0.00, n = 44) though BBS coverage of this species is spotty.    Threats McCown’s Longspur is one of the few grassland species that may benefit from grazing;  higher breeding densities have been recorded on heavily grazed pastures than on less-intensely grazed ones, though response to grazing may be variable based on soil type and region (Ryder 1980). This species is vulnerable to destruction of native shortgrass prairie for agriculture and development. Declines in abundance and distribution have been attributed to land-use practices that destroy native shortgrass prairie, and possibly to restriction of uncontrolled grass fires that serve to maintain stature of breeding habitat (Oberholser 1974, With 1994).    Management Issues and Recommendations Management for McCown’s Longspur in New Mexico should focus on high quality desert grassland habitat, particularly in areas where wintering populations are known to concentrate.    NMPIF Recommendations Where appropriate and possible, seek to manage grazing to maintain high density shortgrass habitat with minimal shrub cover.  Investigate effects of fire and grazing on habitat use, and design management accordingly.    Species Conservation Objectives NMPIF Objectives Monitor statewide to assess winter population trends. Maintain or expand existing wintering populations.     Sources of Information Grzybowski, J. A. 1982. Population structure in grassland bird communities during winter. Condor 84:137-152. Ligon, J. S. 1961. New Mexico birds and where to find them. Univ. New Mexico Press, Albuquerque, NM. Oberholser, H. C. 1974. The bird life of Texas. Volume 2. Univ. Texas Press, Austin, TX. Parmeter, J., B. Neville, and D. Emkalns. 2002. New Mexico Bird Finding Guide. New Mexico Ornithological Society, Albuquerque, NM. Ryder, R. A. 1980. Effects of grazing on bird habitats. Pp. 51–66 in Management of western forests and grasslands for nongame birds (R. M. DeGraff and N. G. Tilghman, Eds.). U.S.D.A. For. Ser. General Tech. Rep. INT–86. U.S. Fish and Wildlife Service. 2002. Birds of conservation concern 2002. Division of Migratory Bird Management, Arlington, VA. 99 p. With, K. A. 1994. McCown’s Longspur (Calcarius mccownii). In The Birds of North America, No. 96 (A. Poole and F. Gill, Eds.). Philadelphia, PA: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.