How sea turtle hatchlings know where to crawl
By Sid Perkins
From Acapulco, Mexico, at a meeting of the American Geophysical Union
Field tests suggest that newly hatched sea turtles need a variety of senses, not just sight, to find their way to the ocean.
The female black sea turtle (Chelonia agassizi) buries her eggs in sand 100 meters or so from the shoreline. As soon as the hatchlings emerge, they head for the water. Most previous studies of how these young creatures find their way into the surf have focused on the role of visual cues such as moonlight, says Gabriel Gutiérrez-Ospina, a neurobiologist at the National Autonomous University of Mexico in Mexico City. However, the results of his group’s experiments now suggest that other senses help the turtles set off in the right direction.