Abstract
The globally threatened bog turtle (Glyptemys muhlenbergii) typically occurs in low-abundance populations of 5 to 50 individuals, yet the conservation value of small bog turtle populations remains unclear. Designing effective reserve networks for this species requires clarification of (1) long-distance dispersal rates and the relevant spatial scales at which gene flow occurs and (2) effective regional monitoring strategies for bog turtle populations and reliable metrics of habitat quality and population health. Using a 10-year capture-recapture dataset from a fen complex in southeastern New York, I estimated vital rate parameters for bog turtles and performed population viability analyses (PVA). In addition, I obtained genetic samples from a complex of 11 discrete bog turtle populations and assessed gene flow based on correlation of allele frequencies at neutral microsatellite loci. Finally, I conducted one season of radiotelemetry (n = 22 individuals) to study bog turtle microhabitat selection and home range. Results suggest that small bog turtle colonies (ca. 20 individuals) may have low extirpation risk (provided age-specific survival rates remain at current, estimated levels) and therefore high conservation value. This result, coupled with small home range size (averaging <0.1 ha), suggests that high-quality fen habitats of 1 ha or less are capable of supporting viable bog turtle populations. Molecular data indicate high rates of gene flow at a fen complex with mean distance ca. 1 km between populations, suggesting that similar complexes should be conserved as single metapopulation units. Regional simulation models indicate that (1) complexes of bog turtle populations comprising >4 inter-connected (annual dispersal rate >1%) populations of >20 individuals may persist for >100 years if core habitat is conserved, and that (2) a 10-year monitoring cycle is probably sufficient to identify imperiled bog turtle populations and mount a timely management response. Translocation of individuals from secure source populations to imperiled populations holds promise as a means for enhancing bog turtle recovery when paired with habitat improvement efforts. Regional conservation planning should focus on establishing and maintaining loosely connected networks of population complexes to mimic historical connectivity patterns and help ensure the long-term persistence of this species.