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Population bottlenecks can reduce genetic diversity and may lead to inbreeding depression. However, some studies have provided evidence that long lifespans buffer negative genetic effects of bottlenecks. Others have cautioned that longevity might merely mask the effects of genetic drift, which will still affect long-term population viability. We used microsatellite data from actual populations of tuatara (Sphenodon punctatus) and eastern massasaugas (Sistrurus catenatus) as a starting point for simulated population declines to evaluate the performance of bottleneck tests under a range of scenarios. We quantified losses in genetic diversity for each scenario and assessed the power of commonly used tests (i.e., M-ratio, heterozygosity excess, and mode-shift) to detect known bottlenecks in these moderate- to long-lived species. Declines in genetic diversity were greater in bottlenecks simulated for eastern massasaugas, the shorter-lived species, and mode-shift and heterozygosity excess tests were more sensitive to population declines in this species. Conversely, M-ratio tests were more sensitive to bottlenecks simulated in tuatara. Despite dramatic simulated population declines, heterozygosity excess and mode-shift tests often failed to detect bottlenecks in both species, even when large losses in genetic diversity had occurred (both allelic diversity and heterozygosity). While not eliminating type II error, M-ratio tests generally performed best and were most reliable when a critical value (Mc) of 0.68 was used. However, in tuatara simulations, M-ratio tests had high rates of type I error when Mc was calculated assuming θ = 10. Our results suggest that reliance on these tests could lead to misguided species management decisions.

Communicating science with nonexperts (SciComm) is an important scientific practice. SciComm can inform decision making and public policies. Recently, seminal reports have indicated that SciComm is a practice in which students should engage. Unfortunately, students have few opportunities to engage in SciComm, partially due to the absence of a framework that can help instructors facilitate such activities. We present a framework of the essential elements of effective SciComm that synthesizes previous work to describe the who, why, what, and how of effectively communicating science with nonexperts. We applied the framework to a lesson for undergraduate biology students and assessed student outcomes. The lesson uses an introduction, assignment sheet, and worksheet to guide students through planning, producing, and describing their SciComm assignment. We assessed the outcomes of the lesson by quizzing students on their knowledge of SciComm and asking about their perceptions of SciComm and the lesson. Students performed well but focused some of their responses on what they were assigned in the lesson instead of what was best for effective SciComm. Moreover, students perceived the lesson positively. This work can be used by practitioners and researchers to understand how to engage students in the important scientific practice of SciComm.

Genetic diversity is fundamental to maintaining the long‐term viability of populations, yet reduced genetic variation is often associated with small, isolated populations. To examine the relationship between demography and genetic variation, variation at hypervariable loci (e.g., microsatellite DNA loci) is often measured. However, these loci are selectively neutral (or near neutral) and may not accurately reflect genomewide variation. Variation at functional trait loci, such as the major histocompatibility complex (MHC), can provide a better assessment of adaptive genetic variation in fragmented populations. We compared patterns of microsatellite and MHC variation across three Eastern Massasauga (Sistrurus catenatus) populations representing a gradient of demographic histories to assess the relative roles of natural selection and genetic drift. Using 454 deep amplicon sequencing, we identified 24 putatively functional MHC IIB exon 2 alleles belonging to a minimum of six loci. Analysis of synonymous and nonsynonymous substitution rates provided evidence of historical positive selection at the nucleotide level, and Tajima's D provided support for balancing selection in each population. As predicted, estimates of microsatellite allelic richness, observed, heterozygosity, and expected heterozygosity varied among populations in a pattern qualitatively consistent with demographic history and abundance. While MHC allelic richness at the population and individual levels revealed similar trends, MHC nucleotide diversity was unexpectedly high in the smallest population. Overall, these results suggest that genetic variation in the Eastern Massasauga populations in Illinois has been shaped by multiple evolutionary mechanisms. Thus, conservation efforts should consider both neutral and functional genetic variation when managing captive and wild Eastern Massasauga populations.

The eastern massasauga Sistrurus catenatus catenatus is a declining species for which a captive breeding program was established in 2006. To effectively manage wild and captive populations, an understanding of genetic diversity within the species is necessary. We analyzed mitochondrial DNA sequences of 186 individuals: 109 wild snakes from 34 U.S. and Canadian counties and districts, all 52 breeding program members (23 of known and 29 of unknown origin), 18 other captives of unknown origin, and 7 outgroup representatives of desert massasauga S. c. edwardsii, and western massasauga, S. c. tergeminus. Statistical parsimony, maximum likelihood, and maximum parsimony analyses all identified eastern massasaugas as divergent from western and desert massasaugas. We found 18 different haplotypes among eastern massasaugas, comprising three geographically and genetically differentiated NADH dehydrogenase II (ND2) subunits that potentially reflect post-Pleistocene range expansion from unglaciated into formerly glaciated regions. Snakes of unknown origin could all be assigned unambiguously to these ND2 subunits. To maintain natural genetic variation, preserve diversity in captive lineages, and allow future augmentation or reintroduction, the Association of Zoos and Aquariums is managing these three geographic ND2 subunits separately within the Eastern Massasauga Species Survival Plan breeding program.

Spatial distributions and movements of aquatic animals are typically defined by the dimensions of the aquatic system in which they live. Aquatic turtles often confound such definitions with terrestrial movements, and movements within the aquatic system remain largely undescribed. We studied the movements of adult female painted turtles (Chrysemys picta) and red-eared sliders (Trachemys scripta) in Reelfoot Lake, a large aquatic system. We determined the distance moved, home-range size, and habitat use to investigate interspecific variation, as well as the influence of habitat dimensions on turtle spatial ecology. Daily movements peaked for both species between May and August. Trachemys scripta exhibited longer movements, maintained larger home ranges, and selected deeper areas of the lake than did C. picta. Compositional analysis indicated that the shoreline habitat was used most frequently by both species, relative to its availability. However, although C. picta selected the shoreline above all ...