We conducted a six-month study on a population of Sternotherus odoratus in Lake Matoaka, investigating population size, movements, and sex ratios. Based on 651 original captures and 627 recaptures, we estimated a lake-wide population size of 1289 (95% confidence interval 878 to 1959). No difference was observed in mean carapace length between the two sexes (males 95.6 mm, females 94.5 mm, t-test p = 0.15). Based on similar capture and recapture locations, almost 80% of turtles captured multiple times exhibited site fidelity. Other turtles tended to move laterally between adjacent trapping locations in the littoral zone of the lake rather than across open water to trapping locations on the opposite shore. The lake-wide male to female ratio differed significantly from unity (1.73:1, p < 0.0001) and males were recaptured more frequently than females. Local environmental variation and seasonal changes in turtle behavior appear responsible for the differential distribution and movements of stinkpot turtles in Lake Matoaka.
Site map of Lake Matoaka located on the campus of the College of William and Mary in southeastern Virginia, USA. Letters refer to turtle trapping locations in the littoral zone. Land dominated by forest is lightly shaded; cleared land is white.