SREL Reprint #2594

Demographic and ecological factors affecting conservation and management of the diamondback terrapin (Malaclemys terrapin) in South Carolina

J. Whitfield Gibbons1, Jeffrey E. Lovich1,2 Anton D. Tucker1,3, Nancy N. Fitzsimmons1,3, and Judith L. Greene1

1Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802 USA
2U.S. Geological Survey, Western Ecological Research Center, 7801 Folsom Boulevard, Suite 101,
Sacramento, California 95826 USA
3Conservation Strategy, Freshwater Turtle Research, Queensland Department of Environment and Heritage,
P.O. Box 1735, Bundaberg, Queensland 4670 Australia

Abstract: We used mark-recapture data from 1274 original captures and 1131 recaptures during a 16-year population study of diamondback terrapins (Malaclemys terrapin) in a South Carolina, USA, salt marsh to examine demography and ecological factors critical for management recommendations and conservation. Adult females were significantly larger but less numerous than adult males. Most of the terrapins captured in the tidal creeks were sexually mature, first- and second-year individuals being absent and third- and fourth-year individuals being scarce, suggesting the use of a different habitat by juveniles. Most individuals exhibited high site fidelity, remaining in the same creek from year to year, although similar creeks were nearby. The observation that individuals rarely moved between adjacent tidal creeks and remained in one small area as adults is of particular significance to management considerations for the species. Terrapin numbers in one creek were high during the 1980s and declined steadily after 1990, with only a single individual being present after 1993. The combination of high site fidelity and limited dispersal by terrapins from other creeks and the onset of recreational crab trapping and other human activities are presumed to have been responsible for the disappearance of the population. Without the implementation of strong measures to assure sustainability of terrapin populations throughout the range, continued population declines are likely.

Keywords: Reptilia; Testudines; Emydidae; Malaclemys terrapin; turtle; conservation; dispersal; management; size; sex ratio; USA; South Carolina

SREL Reprint #2594

Gibbons, J. W., J. E. Lovich, A. D. Tucker, N. N. FitzSimmons, and J. L. Greene. 2001. Demographic and ecological factors affecting conservation and management of the diamondback terrapin (Malaclemys terrapin) in South Carolina. Chelonian Conservation and Biology. 4:66-74.

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