Endangered species that exist in small isolated populations are at elevated risk of losing adaptive variation due to genetic drift. Analyses that estimate short‐term effective population sizes, characterize historical demographic processes, and project the trajectory of genetic variation into the future are useful for predicting how levels of genetic diversity may change. Here, we use data from two independent types of genetic markers (single nucleotide polymorphisms [SNPs] and microsatellites) to evaluate genetic diversity in 17 populations spanning the geographic range of the endangered eastern massasauga rattlesnake ( Sistrurus catenatus ). First, we use SNP data to confirm previous reports that these populations exhibit high levels of genetic structure (overall Fst = 0.25). Second, we show that most populations have contemporary Ne estimates <50. Heterozygosity–fitness correlations in these populations provided no evidence for a genetic cost to living in small populations, though these tests may lack power. Third, model‐based demographic analyses of individual populations indicate that all have experienced declines, with the onset of many of these declines occurring over timescales consistent with anthropogenic impacts (<200 years). Finally, forward simulations of the expected loss of variation in relatively large (Ne = 50) and small (Ne = 10) populations indicate they will lose a substantial amount of their current standing neutral variation (63% and 99%, respectively) over the next 100 years. Our results argue that drift has a significant and increasing impact on levels of genetic variation in isolated populations of this snake, and efforts to assess and mitigate associated impacts on adaptive variation should be components of the management of this endangered reptile.

Managing endangered species in fragmented landscapes requires estimating dispersal rates between populations over contemporary timescales. Here, we developed a new method for quantifying recent dispersal using genetic pedigree data for close and distant kin. Specifically, we describe an approach that infers missing shared ancestors between pairs of kin in habitat patches across a fragmented landscape. We then applied a stepping-stone model to assign unsampled individuals in the pedigree to probable locations based on minimizing the number of movements required to produce the observed locations in sampled kin pairs. Finally, we used all pairs of reconstructed parent-offspring sets to estimate dispersal rates between habitat patches under a Bayesian model. Our approach measures connectivity over the timescale represented by the small number of generations contained within the pedigree and so is appropriate for estimating the impacts of recent habitat changes due to human activity. We used our method to estimate recent movement between newly discovered populations of threatened Eastern Massasauga rattlesnakes (Sistrurus catenatus) using data from 2996 RAD-based genetic loci. Our pedigree analyses found no evidence for contemporary connectivity between five genetic groups, but, as validation of our approach, showed high dispersal rates between sample sites within a single genetic cluster. We conclude that these five genetic clusters of Eastern Massasauga rattlesnakes have small numbers of resident snakes and are demographically isolated conservation units. More broadly, our methodology can be widely applied to determine contemporary connectivity rates, independent of bias from shared genetic similarity due to ancestry that impacts other approaches.

The use of game cameras by wildlife biologists and managers to survey wildlife, particularly medium-and large-bodied mammals, has increased dramatically. Previous attempts to survey small mammals and ectotherms have had limited detection success or were focused solely on a single species. We describe the Adapted-Hunt Drift Fence Technique (AHDriFT), which combines commercially available game cameras and traditional drift fences to survey reptiles, amphibians, and small mammals. Across 4,502 trap-nights at the Merritt Island National Wildlife Refuge, Florida, USA (Jun 2014 to Jun 2015), we recorded images for 2,523 unique vertebrate detections (2% unidentifiable) averaging 0.56 unique triggers/night. Using AHDriFT enables long-duration surveys with high detectability while minimizing observer time. Guideboards increased terrestrial vertebrate image capture at minimal cost. During 1 year of usage, no mortality was documented using this camera-trap system and field time was reduced by 95%, requiring only monthly visits of approximately 3 hr for 9 fence arrays to download images from the camera systems, compared with pitfall or funnel traps that require at least daily monitoring. Ó 2017 The Wildlife Society.

Sea‐level rise due to climate change is a major threat to coastal ecosystems worldwide. Current management to reduce beach erosion often focuses on protecting human structures and research on effects on wildlife is lacking. Using a combination of hierarchical models and generalized linear models, we evaluated how the gopher tortoise (Gopherus polyphemus) colonized constructed dunes along coastal scrub at the Merritt Island National Wildlife Refuge, central Florida, USA. Over 2 years, we surveyed tortoise populations along natural dunes and 2 constructed dunes (completed in 2012 and in 2014) and estimated tortoise density each summer and winter. Our models indicated that tortoise density along the 2014 dune was comparable to that of natural dunes (truex¯ = 0–8 tortoises/ha), and density peaked at a mean of 21 tortoises/ha along the 2012 constructed dune. Gopher tortoises rapidly colonized constructed dunes, and dune construction may represent effective management against habitat loss for this species. © 2017 The Wildlife Society.

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