Depredation of Diamondback Terrapin (Malaclemys terrapin) Nests in North Inlet, SC: Nest Predator Community and the Cues Used by Raccoons to Locate Nests

Predation on diamondback terrapin eggs has been studied in several terrapin populations across their broad geographic range; however, nest predators have not been studied in South Carolina. Objectives of this project were two-fold: first, identify predators of diamondback terrapin eggs in North Inlet, SC; and second, determine the source of olfactory cue(s) used by raccoons to locate terrapin nests. Terrapin nest predators were identified using a combination of camera traps, visual surveys and trackboards. Raccoons were dominant nest predators and depredated 347 of 349 (combined natural and simulated) terrapin nests during the 2013 nesting season. We identified the source of the olfactory cue used by raccoons to locate nests through a series of experiments using simulated terrapin nests. Our results support the conclusion that foraging raccoons primarily utilize the scent of soil disinterred by nesting females, and not scent from the turtles themselves. Lastly, in our efforts to design scent cue experiments, we realized the need for an effective nest predator exclusion device. We conceived and tested a new design for predator exclusion cages that protected 70-100% of nests through three trials (n = 4, 8, 84)