Sage grouse Centrocercus urophasianus are a classic example of a lek-mating species, and are becoming yet another example of a species encountering dramatic human-induced changes to its environment. A study of the patterns of genetic variation across the range of both subspecies and including the unique small-bodied birds in the Gunnison Basin, Colorado was done by sequencing 141 bp or more within region I of the mitochondrial control region. Within Colorado, the same haplotype was present in 31/32 (97%) of the small-bodied birds surveyed in the Gunnison Basin whereas a wider variety of haplotypes was found at each of the five surveyed locales within the range of the large-bodied birds (132 individuals). The predominant haplotype within the Gunnison Basin is at a frequency of 97%, but elsewhere that haplotype is at a frequency of less than 20%. This, and the observation that other haplotypes which predominate in large-bodied birds are not present in the Gunnison Basin provides evidence there has been virtually no recent gene flow into the Gunnison population from large-bodied sage grouse found elsewhere in Colorado. Preliminary sampling from across the western USA revealed similarities across the range among large-bodied birds in that three haplotypes are shared throughout, but there was also a subset of haplotypes that was more localized in distribution and, hence, potentially more informative for defining population subdivision.
Key words: Centrocercus urophasianus, Colorado, control region sequence, Gunnision Basin, mitochondrial DNA, sage grouse, western USA
Thomas W. Quinn, Nate W. Kahn, Nickolas G. Benedict, Stacey Wood & Duane Mata, Department of Biological Sciences, University of Denver, 2101 E. Wesley Avenue, Denver, Colorado 80208, USA
Jessica R. Young, Department of Sciences, Western State College, Gunnison, Colorado 81231, USA
Clait E. Braun, Colorado Division of Wildlife, 317 West Prospect Road, Fort Collins 80526, USA