Functional Ecomorphology in the Diamondback Terrapin (Malaclemys terrapin); the Effect of Head-starting on Morphology and Bite Force


Meeting Abstract

137-6  Tuesday, Jan. 7 14:45 – 15:00  Functional Ecomorphology in the Diamondback Terrapin (Malaclemys terrapin); the Effect of Head-starting on Morphology and Bite Force REISENFELD, K*; MCELROY, E; ROOSENBURG, W; The College of Charleston ; The College of Charleston ; Ohio University reisenfeldk@g.cofc.edu

Head-starting describes the captive rearing and care of animals through their juvenile life stage, followed by release into their native habitats. The goal of head-starting programs is to avoid high mortality of hatchlings and thus increase overall population size. Malaclemys terrapin populations are declining throughout their range due to increased nest predation, road mortality, habitat loss, commercial harvest for food, and bycatch in crab pots (Dorcas et al., 2007). A M. terrapin head-starting program in Chesapeake Bay suggest that survival of accelerated animals is lower than wild animals (Jenkins, 2018). Morphological performance may effect an individual’s ability to gain resources (Elnitsky and Claussen, 2006; Herrel et al., 2002), and therefore reduce survivorship. Bite force is one morphological performance measurement that is affected by diet and corresponding head and body morphometries (Herrel et al., 2018; Marshall et al., 2012). Head-started M. terrapin are fed a soft pellet diet, which may yield individuals with reduced bite force that are unable to forage on the hard-shelled prey accessible to them upon release. Bite force, head, and body morphometries were collected from M. terrapin across all ages on Poplar Island, MD. Bite forces were correlated to body and head size to determine their effect across ontogeny. The force needed to crush prey items found in the Chesapeake Bay was obtained to determine if head-started terrapins are able to forage post-release. We evaluate if bite force and morphometries are different in head-started M. terrapin and therefore explain the reduced survivorship of released individuals.

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