Use of molecular and environmental analyses for integrated in situ and ex situ conservation: The case of the Mexican prairie dog

Abstract

An important step in species conservation is to identify populations that significantly contribute to it. Considering both in situ and ex situ populations provides an integrated approach to the preservation of a species' evolutionary potential. The joint use of molecular and environmental analyses allows conservation schemes to be implemented when reintroducing captive populations, and wild populations to be prioritized for conservation purposes. We used genetic data and environmental analyses to select candidate areas for the reintroduction of a captive population of the Mexican prairie dog, Cynomys mexicanus, and prioritize wild populations for the conservation of this endangered endemic species. We estimated the levels of genetic diversity and differentiation of the captive population and compared them with those of six wild populations. We used species distribution modeling (SDM) to perform forecasts under future climate change scenarios and identify areas with suitable environmental conditions for the populations to persist in the medium to long term. The captive population showed high levels of genetic diversity (Hd=0.692, HE=0.52), but was genetically differentiated from the wild populations. The genetic structure of wild populations should therefore be considered when reintroducing captive Mexican prairie dogs. In the wild populations, we found a correlation between colony area and nuclear genetic diversity, suggesting that genetic drift and/or inbreeding have been stronger in smaller colonies. The occupied climate space was well differentiated among wild colonies. The impact of agriculture and roads was stronger in the northeastern area of the species range, where SDM forecasts suggest that environmental conditions may remain suitable in the future. Finally, we identified three colonies as conservation priorities based on both genetic and ecological criteria.