SREL Reprint #3304

Temporal and spatial variation in survivorship of diamondback terrapins (Malaclemys terrapin)

Lynea R. Witczak1, Jacquelyn C. Guzy2, Steven J. Price3, J. Whitfield Gibbons4,
and Michael E. Dorcas1

1Department of Biology, Davidson College, Davidson, North Carolina 28035 USA
2Department of Biology, University of Arkansas, Fayetteville, Arkansas 72701 USA
3Department of Forestry, University of Kentucky, Lexington, Kentucky 40546 USA
4University of Georgia Savannah River Ecology Laboratory, Aiken, South Carolina 29802 USA

Abstract: The diamondback terrapin (Malaclemys terrapin) is a species of conservation concern that has experienced noticeable declines throughout its range. Mark–recapture studies have been conducted on terrapins at Kiawah Island, South Carolina, since 1983, and during the early 1990s, this population began to decline. Our objectives were to evaluate current spatial and temporal variation in survivorship and compare current estimates of survivorship with those calculated from 1983 to 1999 in a previous study. We used an 11-year data set (2003 to 2013) in a capture–mark–recapture analysis to estimate the survivorship of terrapins in 5 creeks. Among creeks, annual survivorship estimates ranged from 61% to 82% with no difference between the sexes. Survivorship was lower than that documented for this population in the early 1990s. Recent anthropogenic habitat modification, such as the construction of docks, roads, and housing developments, as well as activities such as crab-trapping, likely play a role in low annual survivorship. Results from this long-term study are essential for understanding terrapin population status and can inform conservation and coastal ecosystem management.

Keywords: Diamondback terrapin; turtle; mark–recapture; population decline; long-term study; Kiawah Island; South Carolina; habitat modification

SREL Reprint #3304

Witczak, L. R., J. C. Guzy, S. J. Price, J. W. Gibbons, and M. E. Dorcas. 2014. Temporal and spatial variation in survivorship of diamondback terrapins (Malaclemys terrapin). Chelonian Conservation and Biology 13(2): 146-151.

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