Breeding Habitat:Grassland
Nest Type:Open-cup nesting passerine
Migration Status:Short distance migrant
Nest Location:Ground-low nesting
The McCown's Longspur is a characteristic summer resident of short-grass prairie communities on the western Great Plains of North America. In addition to native prairies, they also regularly occur in overgrazed habitats where the vegetation is very short (Andrews and Righter 1992). They prefer more xeric habitats with shorter vegetation than Chestnut-collared Longspurs.
Along BBS routes, this species is most numerous in southwestern Saskatchewan and locally in Montana and Wyoming (Relative Abundance Map). Its winter range is primarily in the remaining grasslands of the southwestern U.S. from west Texas into Arizona.
As is true for many grassland birds, McCown's Longspur populations have undergone noticeable declines during historic times. Their population declines were most apparent during the first decades of the twentieth century, especially 1905-1930 in North Dakota when these longspurs disappeared from most of their range in the state (Stewart 1975). Similar declines were apparent in the winter range during this period, especially in portions of Arizona and Texas (Phillips et al. 1964, Oberholser 1974). Another sharp decline was apparent in the Texas panhandle after 1940.
The most significant population declines occurred prior to the initiation of the BBS. Since 1966, BBS data suggest McCown's Longspur population trends are generally mixed non-significant increases and declines (Trend List). However, these trend estimates are relatively imprecise and should be veiwed with caution. Considerable annual fluctuations in abundance and inconsistent coverage of routes contribute to the imprecision of these estimates. Small sample sizes preclude detailed analyses of trends within states/provinces and physiographic strata. The trend map shows a mixed pattern of increases and declines, perhaps with increases predominating (Trend Map). The survey-wide indices are variable, especially prior to 1970 but show an increasing tendency during the later years (Survey-wide Annual Indices). Trends in the U.S. are largely reflected in these survey-wide indices. Indices for states/provinces and strata are quite variable and show no consistent temporal patterns. Similar annual fluctuations are apparent in the CBC data. Hence, those trend estimates should also be viewed with caution.
Habitat loss was believed to be primarily responsible for the historic declines in McCown's Longspur populations, especially the conversion of short-grass prairies to cultivated fields (Stewart 1975). Some populations are still affected by this habitat loss. However, factors on the wintering grounds undoubtedly contributed to these declines, as breeding pairs have even disappeared from suitable native short-grass prairies (Stewart 1975). Their winter ecology is poorly understood, as are the historic factors affecting these longspurs on their winter range.
Andrews, R., and R. Righter. 1992. Colorado birds. Denver Mus.
Natur. Hist., Denver, CO. 442 pp.
Phillips, A., J. Marshall, and G. Monson. 1964. Birds of Arizona.
Univ. of Arizona Press, Tucson, AZ. 212 pp.
Oberholser, H.C. 1974. The bird life of Texas, Vol. 2. Univ. of
Texas Press, Austin, TX. 538 pp.
Stewart, R.E. 1975. Breeding birds of North Dakota. Harrison
Smith, Lund Press, Minneapolis, MN. 295 pp.