SEA-FINDING BY HATCHLING SEA TURTLES
Hatchling sea turtles typically emerge from their nests at night and begin to crawl seaward almost immediately. Moving rapidly from the nest to the ocean is important to the survival of young turtles, because hatchlings cannot defend themselves against terrestrial predators such as racoons, foxes, ghost crabs, and shore birds.
In principle, hatchlings might move toward the sea by inheriting instructions to crawl toward a specific direction. Experiments indicate, however, that turtles instead use cues specific to their location to guide themselves to the sea. For example, when hatchling green turtles were translocated from the east coast of Costa Rica to the west coast, they crawled westward toward the sea in the new location, even though such headings would have led inland at the original emergence site (Carr and Ogren, 1960).
Given that hatchling sea turtles appear to use local visual cues to find the ocean, what environmental cues are available that might lead turtles toward the sea?