How sea turtles navigate across vast expanses of seemingly featureless ocean has remained a mystery for decades. Recent experiments have revealed that hatchling loggerhead turtles can sense two different features of the earth's magnetic field that may provide information on global position. These results suggest that the key to the sea turtle navigational system may be an ability to determine location using magnetic field features. The proposed research has three major objectives. The first is to investigate how hatchling loggerheads respond to magnetic features marking various locations throughout the North Atlantic. A second is to examine whether turtles can distinguish between the magnetic features that mark different coastal regions that are contiguous and relatively close together, as adults would presumably need to do if they use magnetic features to navigate into the vicinity of their natal beaches. A final set of experiments investigates what specific feature or features of the earth's field the turtles detect and respond to.
Results of the research are likely to reveal previously undiscovered mechanisms of position-finding and navigation that are used not only by sea turtles, but by diverse animals such as migratory birds, commercially important fishes (e.g., salmon), and marine mammals. In addition, understanding how sea turtles navigate, and how they find their natal regions as adults, may benefit conservation efforts to save these threatened and endangered species from extinction. Results may also reveal new navigational methods relevant to human guidance systems.
