Excluding mammalian predators from diamondback terrapin nesting beaches with an electric fence

Abstract

Over the past century, diamondback terrapin (Malaclemys terrapin) populations in the Chesapeake Bay region of the United States have declined from their historic abundance. One factor contributing to the decline is increased predation on terrapin nests by raccoons (Procyon lotor) and foxes (Vulpes vulpes and Urocyon cinereoargenteus). We studied the use of electric fences to deter these predators from nesting beaches along the lower Patuxent River, Calvert and St. Mary’s Counties, Maryland. Over the two-year study, the predation rate within treatment (fenced) plots was 40% (4 of 10 nests) compared to 69% (20 of 29 nests) in control plots. We believe that electric fences have potential as a conservation technique for reducing mammalian predation on diamondback terrapin nests.