Gregory Wadsworth, Ph.D., Associate Professor of Biology
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Edward Standora, Ph.D., Professor of Biology
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Harold Avery, Ph.D., Adjunct Faculty of Biology
Christopher Pennuto, Ph.D., Professor of Biology
Daniel Potts, Ph.D., Associate Professor of Biology
Increasing urbanization of the Barnegat Bayestuary in New Jersey has subjected northern diamondback terrapins to substantial habitat loss. Understanding whether terrapins have homing behavior, and determining the types of orientation cues they use to aid in this behavior, is important for conservation management. To test their homing behavior, nine non-gravid female terrapins were outfitted with biotelemetry tracking devices and data loggers and were displaced 4 km north and/or south. Eight of nine terrapins successfully returned home; the one terrapin that did not return home was inadvertently captured in a crab pot. Urbanization and shoreline development of the north displacement location may be causing terrapins to make quicker movements home compared to the ‘natural’ south displacement location. A terrestrial arena that blocked terrapins from perceiving visual landmarks was used to test orientation in both male and female terrapins that had been captured to the south or east of the testing site. Only male terrapins captured from the east exhibited apparent homeward orientation, suggesting that terrapins orient toward water rather than home. Terrapins from the south tested under overcast skies and during the afternoon, and females captured from the south, tested separately, had easterly orientation, suggesting there was orientation toward open water as well within these groups. While displaced terrapins were able to return home, terrapins tested in the arena appeared to orient toward water, suggesting that the orientation cues used in homing may not be available to the terrapins on land, within the arena. Understanding both homing behavior and orientation will give managers insight into how terrapin home ranges might be protected. Since terrapins are able to return home after displacement, protection measures will be needed for all potential home ranges of the terrapins and relocation efforts may require the displacement of terrapins to more distant areas.
Lainhart, Nicole M., "Homing Behavior in Response to Displacement and Orientation of the Northern Diamondback Terrapin (Malaclemys terrapin terrapin) in Barnegat Bay, New Jersey" (2013). Biology Theses. 8.