Genetic analysis reveals hidden threats and new motivation for conservation translocation of black-tailed prairie dogs at the northern limit of their range

Abstract

Biodiversity loss continues at unprecedented rates; to slow loss, conservation practitioners are working to remove species from risk of extinction. But, even when species are no longer at risk of extinction, they likely exist in small, isolated populations, especially at range edges, and their long-term persistence is uncertain. The northernmost population of the black-tailed prairie dog (Cynomys ludovicianus), located in Grasslands National Park, Saskatchewan, Canada, is potentially isolated from the core of the prairie dog range and has experienced dramatic population fluctuations. To better understand the genetic health of this population, we genotyped 566 individuals alongside individuals from Montana (N = 48) and South Dakota (N = 40), at 15 microsatellite loci. We also generated over 1000 base pairs of mtDNA sequence data for a subset of individuals from each of these three locations. The microsatellite data indicate that the Saskatchewan population has extremely low variability (HO = 0.231), and a high level of inbreeding (FIS = 0.14) compared to other prairie dog populations. Analysis of population structure indicates that the Saskatchewan population is isolated from the black-tailed prairie dog range. However, data from the mtDNA indicates the Saskatchewan population was connected to Montana in the recent past. Considering these results, it is important to evaluate management strategies such as genetic rescue via translocations to increase diversity and circumvent negative impacts of inbreeding. While translocating individuals presents challenges, we believe this may be the best option for Saskatchewan prairie dogs given the continuing impacts of climate change and disease.

Keywords

• Black-tailed prairie dog
• Conservation genetics
• Cynomys ludovicianus
• Genetic rescue
• Inbreeding