Magnetic Navigation

It's time for this young loggerhead turtle to go to work. You can tether turtles in these little cloth harnesses, put them in this tank, and provide a dull swimming place. University of North Carolina biologist Ken Loman studies sea turtles that are programmed from birth for an extraordinary journey. Mother turtles bury the eggs on the beach and then return to the sea, and the eggs hatch about 50 to 60 days later. Supported by the National Science Foundation, Loman is studying how these reptiles use the Earth's magnetic field to navigate a 5-to-10-year journey around the Atlantic Ocean. The turtles seem to inherit a set of responses that tell them what to do when they encounter specific magnetic fields at particular locations. This animal magnetism can be a lifesaver, and one field off Portugal triggers the turtles to turn south. If they don't, they'll likely die, swept into frigid North Atlantic waters. In one lab test, turtles responded to the magnetic field similarly to what they would encounter off the coast of Florida. The great majority of them turned Southeast. This is an exciting finding because southeasterly orientation in this part of the world would presumably take turtles further into the Gulfstream. So, turtles have what might be considered an accrued global positioning system that is based on the Earth's magnetic field. Check out this experiment. These turtle moves may look odd. The turtles will act out their swimming behavior in the air. But this wave simulator recreates the first environmental cue that hatchling turtles respond to. Swimming into waves is a highly reliable trick that the turtles use to guide themselves offshore.