Nesting Habitat Creation Enhances Recruitment in a Predator-Free Environment: Malaclemys Nesting at the Paul S. Sarbanes Ecosystem Restoration Project
Aquatic turtles worldwide are plagued with habitat loss due to development and shoreline alteration that destroys the terrestrial–aquatic linkage which they must cross to reproduce successfully. Furthermore, nesting habitat loss can concentrate nesting, increasing nest predator efficiency. We describe how the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island created nesting habitat for Malaclemys terrapin (Diamondback Terrapin), and document nesting success in response to construction progress and the absence of raccoons and foxes, the primary nest predators. We monitored terrapin nests throughout the nesting seasons from 2002 to 2011 to determine overall and within-nest survivorship. Female terrapins began nesting on the restoration project within 1 year but planned construction during the study eliminated some nesting areas and opened previously inaccessible areas. Overall, nest survivorship was considerably higher than mainland nesting areas due to the absence of raccoons and foxes on the island and within-nest survivorship was similar. Egg size, hatchling size, and the frequency of shell scute anomalies were similar to other terrapin populations, suggesting normal developmental conditions on the island. We documented annual variation in hatchling size that correlated negatively with mean air temperature during the incubation season. Our results indicate that restored or created isolated island habitat can be located rapidly by terrapins and can become an important source of recruitment in regions where nesting habitat is limited and predation is high. Poplar Island illustrates how habitat loss and restoration can affect turtle populations by revealing the changes in nesting patterns and success in newly created, predator-free habitat.
Roosenburg, Willem M.; Spontak, Dana M.; Sullivan, Sean P.; Matthews, Eva L.; Heckman, Melanie L.; Trimbath, Ryan J.; Dunn, Robert P.; Dustman, Emily A.; Smith, Lisa; and Graham, Leah J., "Nesting Habitat Creation Enhances Recruitment in a Predator-Free Environment: Malaclemys Nesting at the Paul S. Sarbanes Ecosystem Restoration Project" (2014). Biology Faculty Research. 191.