Data from: Contrasting patterns of inbreeding and inbreeding depression in co-occurring spotted turtle and eastern box turtle populations
Data files
Dec 29, 2025 version files 24.88 KB
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README.md
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SWGAdultLeukocyteProfile.csv
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SWGBoxTurtleGenotypes.csv
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SWGFemaleMCP.csv
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SWGSpottedTurtleGenotypes.csv
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Abstract
Maintenance of genetic diversity is critical for preserving adaptive potential and avoiding inbreeding depression and further population decline. Eastern box turtles and spotted turtles co-occur in remnant oak savanna landscapes, and while both species have experienced habitat fragmentation, remaining spotted turtle populations are smaller, more isolated, and potentially more vulnerable to inbreeding depression than box turtle populations. To test this prediction, we estimated population size, measured total area occupied, quantified home range size, measured baseline physiological stress levels, and calculated inbreeding coefficients in three populations of both species. We used egg-hatching success and hatchling survival to overwintering as potential evidence of inbreeding depression. Spotted turtles had smaller population sizes, occupied smaller geographic areas, had smaller home ranges, and had higher baseline physiological stress levels than box turtles. Box turtle populations had higher inbreeding coefficients and lower rates of egg-hatching success and hatchling survival to overwintering compared to spotted turtles, suggesting that the box turtle populations are experiencing inbreeding depression. A top priority for conserving these vulnerable turtle species should be the preservation of intact tracts of habitat, restoring connectivity among sub-populations, and preventing further fragmentation of occupied habitat by roads in order to promote gene flow and random mating.
https://doi.org/10.5061/dryad.pvmcvdnwc
Description of the data and file structure
Characteristics of three populations each of eastern box turtles (Terrapene carolina carolina) and spotted turtles (Clemmys guttata) in northwestern Ohio and southern Michigan in 2018-2019. Adult females (FemaleID2) of each species (Species) from three study sites (Site) in Ohio and Michigan (State) were radio-tracked over two years (Year) throughout the active seasons, and annual home ranges were calculated for each individual in each year as minimum convex polygons, using one radio-location per day (MCP in “SWGFemaleMCP.csv”). From blood smear slides prepared from adult (AdultID) males and females (Sex) of each species (Species) at each study site (Site) in Ohio or Michigan (State), we counted ~100 white blood cells (CellsCounted in “SWGAdultLeukocyteProfile.csv”) and classified each cell as a Heterophil, Lymphocyte, Monocyte, Eosinophil, or Basophil; the ratio of heterophils:lymphocytes (HLRatio) was used as a proxy for each individual’s physiological stress level. Date was the date blood was collected. To assess genetic diversity and calculate the inbreeding coefficient of each population, we extracted DNA from blood samples from adults of each species at each site. We amplified spotted turtle DNA at eight microsatellite loci previously developed for bog turtles (King and Julian 2004), and we amplified eastern box turtle DNA at six microsatellite loci using species-specific primers developed by Kimble et al. (2011). All microsatellites for both species were sized and visualized using AB GeneMapper software; genotypes at each locus in three different populations (Population) are shown in the files “SWGSpottedTurtleGenotypes.csv” (Locus1, Locus2, Locus3, Locus4, Locus5, Locus6, Locus7, and Locus8) and “SWGBoxTurtleGenotypes.csv” (Locus1, Locus2, Locus3, Locus4, Locus5, and Locus7). Data on reproductive success in each population, which were assessed as potential evidence of inbreeding depression, have been previously published (Refsnider et al. 2021, “SWGHatchlings.csv,” doi: 10.17632/jd64t5prvn.2).
Access information
Other publicly accessible locations of the data:
- Refsnider et al. 2021, “SWGHatchlings.csv,” doi: 10.17632/jd64t5prvn.2