Thursday, Jul. 31, 2014
82 ° Partly Cloudy
Dr. Soraya Bartol|
|Course||BIO 375: Topics in Tropical Biology|
Once sea turtle hatchlings leave the nest, they are under intense predation pressure from terrestrial carnivores (e.g., vultures, crabs, possums, mongoose, dogs, and night herons) and must find the sea rapidly. It is thought that hatchlings use multiple cues to find the sea post-emergence from the nest, but rely primarily on vision. The role of visual cues on leatherback (Dermochelys coriacea) sea-finding behavior was tested in Grand Tacarib, Trinidad. Hatchlings were collected as they emerged from the nest and placed in a holding container. A 4m diameter circular arena was constructed in situ on the beach by digging a 30 cm deep by 15 cm wide trench. Thin boards were used to divide the trench into equal sized compartments. Hatchlings were placed in the center of the arena as a group (depending on the number taken from the nest) and monitored for 15 minutes, after which counts were taken from each compartment of the trench. Multiple trials involving various sensory cues were performed on each group of turtles, including trials with 1) artificial vegetation silhouettes, 2) artificial lighting (similar to those found with commercial development), 3) silhouettes and lights in combination, 4) all horizon visual stimuli removed, and 5) all visual stimulation removed. As observed in other species of sea turtles, light was an important orientation cue in the experimental trials, with shadows and silhouettes playing important roles.
2008 VFIC Summer Student Science Research Competitive Grant Program
Association of Southeastern Biologists, Birmingham, AL, April '09