Re-examination of the historical range of the greater prairie chicken using provenance data and DNA analysis of museum collections

Abstract

The extent to which a species has declined within its historical range is commonly used as an important criterion in categorizing the conservation status of wild populations. The greater prairie chicken (Tympanuchus cupido) has been extirpated from much of the area it once inhabited. However, within a large part of this area the species is not considered to be native, warranting no recovery effort or special protection. Demographic analysis based on provenance data from 238 specimens from museum collections in addition to genetic analyses of 100 mtDNA sequences suggest this species was native to the northern prairies, extending from central Minnesota to Alberta, Canada. Provenance data from 1879 to 1935 indicate that T. cupido would have required colonization and establishment of populations on an average 11,905 km 2 every year, with an estimated per capita growth rate of 8.9% per year. These rates seem unrealistic given the limited dispersal and high mortality rates reported for this species. A survey of mtDNA sequences from ‘‘original’’ and ‘‘expanded’’ ranges revealed no differences in levels of sequence diversity within ranges (p=0.018; SE=0.004) but significant levels of genetic differentiation (FST=0.034; P=0.013), which suggest that these populations have been relatively isolated for significant evolutionary time periods. DNA mismatch distributions fit a sudden expansion model consistent with a post-Pleistocene expansion of the species, which coincides with the expansion of prairies into the Canadian plains about 9000 years before present. This study demonstrates the value of museum collections as stores of ecological and genetic information fundamental for the conservation of natural populations, and suggests that the current status of the greater prairie chicken should be re-evaluated within all areas where this species may occur, but is now considered non-native.