The effect of dune vegetation on leatherback hatchling’s sea-finding ability

Abstract

Leatherback turtles, Dermochelys coriacea, are affected by a range of anthropogenic stressors throughout their range. However, little is known about the species’ responses to natural threats such as dune vegetation, which can have a negative effect on the quality of nesting habitats. In this study, we assessed the potential impact of Ipomoea pes-caprae on the sea-finding abilities of leatherback hatchlings at the Pacuare Nature Reserve on the Caribbean coast of Costa Rica. To analyse their effects on hatchling behaviour, we measured and compared the speed at which hatchlings managed to reach the water at open beach locations and vegetated locations. We recorded nest locations of 1491 nests, which were left in situ, and 784 that were relocated between 2012 and 2014. The majority of in situ nests were located in areas where the vegetation was denser than in open beach. We found that dune vegetation had a negative effect on hatchling speed, which led to an increased exposure time to predators and dehydration and could potentially entail extreme physiological stress affecting hatchling mortality. Thus, the presence of vegetation might negatively influence the suitability of nesting habitats if beach erosion processes increase on nesting grounds in the future.