Predation of diamondback terrapin (Malaclemys terrapin) nests by nocturnal mammals: implication for the conservation of a Rhode Island endangered species

Richard Mercer


The embryos and hatchlings of diamondback terrapins (Malaclemys terrapin) are susceptible to predation by nocturnal mammalian predators.  There has been an absence in studies conducted on the effects of nocturnal mammalian predation on diamondback terrapin nesting ecology in Rhode Island.  The objectives were to: (1) quantify relationships between temporal periods of diamondback terrapin nesting and nocturnal mammalian predation; and (2) determine the main species of nocturnal mammals responsible for predated nests.  Daily observations of nesting females, predated nests, protected nests with emerging hatchlings, and videographic observations of nocturnal mammalian predators were documented at Doug Rayner Wildlife Refuge, Barrington, Rhode Island.  After using a linear regression analysis, neither nesting females nor protected nests with emerging hatchlings were significantly related to nest predation.  Nest predation was greatest during the nesting period of diamondback terrapins.  The most frequently observed predators documented were raccoons (Procyon lotor) and striped skunks (Mephitis mephitis).  Raccoons and striped skunks were the main species predating diamondback terrapin nests.  Future researches could analyze the association between other species of predators and diamondback terrapin offspring mortality.