Implications of Small Population Size in a Threatened Pitviper Species

Abstract

Abstract Destruction and fragmentation of wildlife habitat often results in small, isolated populations that are highly susceptible to extirpation. In many cases, however, estimates of population size are lacking, precluding accurate assessments of population viability and sound conservation management recommendations. The Eastern Massasauga (Sistrurus catenatus) is a federally threatened pitviper species that has been extirpated throughout much of its historic range attributable to agricultural conversion of wetland habitat and other synergistic threats. Population size is generally unknown among extant massasauga populations, making site-specific management difficult. In this study, we estimated genetic effective population size (Ne) and census population size (Nc) for Eastern Massasaugas at two sites in southwest Michigan. For each population, we used mark–recapture models to estimate Nc and the linkage disequilibrium method to estimate Ne. Our results revealed small Nc, with approximately 108 (95% CI ...