Genetic diversity and genetic structure near the range periphery of a reintroduced endemic grassland ungulate

The reintroduction of a species into its historical range can present challenges for wildlife managers, particularly when it occurs near the edge of that species’ range and the population is isolated from others. One important aspect of reintroductions is the selection of source populations that best suit local conditions. Additionally, movement and gene flow between reintroduced and extant populations is important for maintaining genetic diversity and evolutionary processes but can be highly influenced by habitat quality, quantity, intactness, and landscape permeability. The reintroduction of pronghorn (Antilocapra americana) into the Flint Hills region of east-central Kansas from the late 1970s through the early 1990s resulted in the establishment of a small population (~ 30 individuals) originating from southwest Wyoming and southeast Colorado. We collected pronghorn fecal samples from the Flint Hills region and from a historical population in western Kansas for DNA analysis to compare, predict, and model genetic diversity, gene flow, isolation, and genetic drift within the Flint Hills population since reintroduction. Our results indicated the average observed heterozygosity from the Flint Hills (0.68) was slightly higher than in western Kansas (0.61), and the average number of alleles per locus were similar (6.1 and 6.2 respectively). Pairwise FST (0.09, p = 0.00001) and G”ST (0.15) indicated slight restriction of gene flow, but not complete isolation between the two groups. Shared ancestry was detected between both groups which may be either through recent gene flow, historical gene flow or similar source populations. The higher genetic diversity found in the Flint Hills population may be attributed to behavioral isolation between the two source populations, the underestimation of their population size, or long-distance immigration from other populations. Additionally, changes in agricultural practices and higher habitat fragmentation in western Kansas may be limiting local and regional pronghorn movement and gene flow. Our results provide additional insight into potential factors influencing the diversity and structure within small, isolated populations when considering future reintroductions of pronghorn and other wildlife species.