Little fox on the prairie: genetic structure and diversity throughout the distribution of a grassland carnivore in the United States

Abstract

The Great Plains region is fragmented by natural and anthropogenic sources, yet the interaction between habitat fragmentation and genetic structure in this region has received limited study. Swift fox (Vulpes velox) are closely associated with short and mixed grass ecosystems, providing an opportunity to study patterns of gene flow, diversity and genetic structure in this area. We collected 589 samples throughout the species’ distribution in the United States and analyzed these samples using 15 microsatellite loci and a 250 base pair sequence of the mitochondrial DNA control region. We detected three levels of spatial genetic structure using microsatellite markers and identified six mitochondrial haplotypes, five of which showed spatial clustering. Differentiation between groups was significant while genetic diversity within groups was generally high. Anthropogenic influences, particularly agriculture, appear to reducing gene flow, especially in the central portion of the species’ range. Conservation measures should be taken to remediate these impacts and to maintain future gene flow in light of expected agricultural expansion in the Great Plains. Potential evolutionary significant units are identified, although further investigation using ecological indicators and adaptive loci is recommended to characterize the adaptive distinctiveness of swift fox populations.