Did you know that many animals have a built-in compass? In marine turtles magnetite crystals, which act just like a compass, are located deep within their brains. Magnetite allows marine turtles to use the earth’s magnetic fields to navigate long distances. This unique physical feature helps marine turtles identify the location of both their feeding and nesting grounds.
Marine turtles display amazing migratory behaviors. By imprinting on chemical, magnetic, and astronomical information of their natal beach while making their way from their nests to the sea, hatchlings are able to return as adults to the beach of their birth. Sea turtles have the ability to memorize the characteristics of their birth beach which allows them to return and maintain a stable nesting population world wide. After hatching, young turtles scurry down the beach toward the water. During this rush to the sea, hatchlings have been observed burrowing their noses into the ground and usually raising their little heads with a mouth full of sand. Hatchlings open and close their mouths as if tasting. This behavior is thought to be a way of learning the chemical cues or 'flavor' of their birth place.
When hatchlings become adults ten to fifteen years later, both male and females make their way back to their birth place to reproduce. The females will come out of the water and onto the beach to lay their eggs, while males stay in the water. Females do not possess the maternal instinct of mammals, therefore the eggs are abandoned and the hatchlings must survive without the help of their parents.
Martin, R. Aidan, Sept. 1994. Diver Magazine.Living Loadstones http://www.elasmo-research.org/education/topics/s_lodestones.htm
Gerrow, Elizabeth. 2002. Animal Electromagnetism and Waves (ANEMAW) Cheloniidae caretta (Loggerhead Sea turtle) . http://members.fortunecity.com/anemaw/othermag.htm