SREL Reprint #2035

The effect of sample size and study duration on metapopulation estimates for slider turtles (Trachemys scripta)

Vincent J. Burke, Judith L. Greene, and J. Whitfield Gibbons

Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802, USA

Abstract: We analyzed data from 26 yr of spatially extensive mark and recapture studies on slider turtles (Trachemys scripta) to describe the effects of mark-recapture effort and study duration on metapopulation size estimates. Estimates were constructed for a metapopulation that encompasses aquatic habitats exhibiting interchange of individuals with Ellenton Bay, a 10 ha wetland on the Savannah River Site near Aiken, South Carolina. Disjunct populations were included in the Ellenton Bay metapopulation (EBMP) if recaptures of marked slider turtles indicated interchange of individuals between that population and the slider turtle population at Ellenton Bay. Recapture data indicated that the EBMP encompasses habitats 3.5 km from Ellenton Bay. Of 1660 slider turtles originally marked in Ellenton Bay, 65 (3.9%) were recaptured in disjunct aquatic habitats, suggesting that detection of interchange of individuals requires high marking effort. New aquatic habitats in the EBMP continued to be recognized 22 yr after the onset of mark-recapture efforts. The results of this analysis suggest that identification of metapopulations requires spatially extensive sampling, high marking effort, and studies of sufficient duration to allow time for detection of movements to distant populations.

Keywords: Reptilia; Chelonia; Emydidae; Trachemys scripta; Turtles; Carolina bay; Metapopulation; Conservation

SREL Reprint #2035

Burke, V.J., J.L. Greene, and J.W. Gibbons. 1995. The effect of sample size and study duration on metapopulation estimates for slider turtles (Trachemys scripta). Herpetologica 51:451-456.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).