Calcarius ornatus (Townsend, 1837)
Basis for Listing
The chestnut-collared longspur occurs across the northern Great Plains and the southern Prairie Provinces of Canada. Within this range, the species tends to be localized in abundance, or semicolonial. Chestnut-collared longspur populations in Minnesota and Nebraska have been greatly reduced, and the species no longer breeds in Kansas, where it was once considered abundant. In North Dakota, the chestnut-collared longspur population declined by about 33% from 1967 to 1993 (Igl and Johnson 1997). During the nineteenth century, the chestnut-collared longspur occurred throughout the dry, upland western prairie of Minnesota, from Jackson County north to the Canadian border. It was most abundant in the southwestern counties, where more suitable dry prairie habitat was available. As settlement progressed, however, the chestnut-collared longspur rapidly disappeared from that quarter of the state, and by 1930 it was found in only a few isolated colonies on the Glacial Lake Agassiz beach ridges of the Red River Valley (Roberts 1932).
Chestnut-collared longspurs are named for the long, slender claw on their hind toe and the rusty color on the nape of their neck. In male chestnut-collared longspurs, the black crown and underparts contrast sharply with the buffy face and chestnut collar. The female's plumage is dull brownish, with some dark mottling on the breast and belly, and only a trace of chestnut on the nape. Both sexes have a distinctive largely white tail, with a central dark triangle. The male's song is similar to that of the western meadowlark (Sturnella neglecta), although not as loud or musical. The flight song, a two-syllable kittle, is also diagnostic.
The chestnut-collared longspur prefers native prairie, establishing breeding territories in well-drained sites away from trees and shrubs. In Minnesota, it occurs almost exclusively in relatively dry, moderately grazed prairie. Elsewhere in its breeding range, the species is typically found on grazed, hayed, or mowed mixed-grass prairies, or other areas with short, sparse vegetation and little or no litter accumulation. Although chestnut-collared longspurs are not known to nest on agricultural lands, these areas serve as important foraging sites, particularly when planted with wheat or sunflowers (Wyckoff 1986a).
Biology / Life History
Chestnut-collared longspurs overwinter on grasslands in the southern U.S. and northern Mexico, and usually return to Minnesota around April 15th. Males exhibit a high degree of site fidelity, and tend to return to the same nesting site in consecutive years. They defend circular territories of less than 1 ha (2.5 ac.), although territory size may increase if habitat is marginal. Nests are constructed in a depression on the ground, usually under a clump of grass, and lined with soft grasses and animal hair. An average of four eggs are laid, which females incubate for around 10 days. The chicks leave the nest about 10 days after hatching, and begin to fly several days later. The parents continue to feed the young for up to two weeks after they have left the nest. If the female begins another brood right after the first has fledged, as is often the case, the male assumes all care of the fledglings (Harris 1944). Chestnut-collared longspurs feed by walking along the ground and gleaning insects, spiders, and grass seeds from the vegetation (Hill and Gould 1997).
Conservation / Management
In Minnesota, the only annually occupied breeding colony of chestnut-collared longspurs occurs in the Felton Prairie area of Clay County. The longspur population and habitat quality in this area should be monitored annually for changes. Moderate grazing or haying of the native prairie should be employed to maintain Felton Prairie's suitability as chestnut-collared longspur breeding habitat. However, extreme or long-term grazing pressure can change the composition of plant species from forbs to graminoids (Wyckoff 1986a), and some areas near breeding colonies at Felton Prairie are beginning to exhibit these characteristics. Managing these areas to make them more conducive to chestnut-collared longspurs could result in an expansion of the population. Spring burning is not recommended when managing for this species, as it reduces both nesting cover and the insects and seeds that longspurs feed upon (Wyckoff 1986a). Gravel quarrying in the Felton Prairie area has had negative impacts on native prairie, and continues to be a threat to the chestnut-collared longspur population. Wind farm development on the beach ridges also has the potential to impact this population and should be carefully designed, with all towers placed outside of the species' native prairie habitat.
Conservation Efforts in Minnesota
Observers reported 50-60 male chestnut-collared longspurs in the Felton Prairie area in the early 1980s, and in 1985 an intensive survey revealed a minimum of 132 males on the site. Chestnut-collared longspurs continue to be present annually at Felton Prairie. Much of the remaining potential range for this species in the state has been surveyed by the Minnesota Biological Survey, and few additional breeding locations have been documented.
References and Additional Information
Harris, R. D. 1944. The Chestnut-collared Longspur in Manitoba. The Wilson Bulletin 56(2):105-115.
Hill, D. P., and L. K. Gould. 1997. Chestnut-collared Longspur (Calcarius ornatus). Number 288 in A. Poole and F. Gills, editors. The birds of North America. The Birds of North America, Inc., Philadelphia, Pennsylvania.
Igl, L. D., and D. H. Johnson. 1997. Changes in breeding bird populations in North Dakota: 1967 to 1992-93. The Auk 114:74-92.
Roberts, T. S. 1932. The birds of Minnesota. Volume 2. University of Minnesota Press, Minneapolis, Minnesota. 821 pp.
Wyckoff, A. M. 1986a. A relict population of Chestnut-collared Longspurs in Western Minnesota. The Loon 58(1):3-11.
Wyckoff, A. M. 1986b. Longspurs breed in Traverse County. The Loon 58(1):51.