sst-0512

It’s time for this young loggerhead turtle to go to work. We can tether turtles in these little cloth harnesses, put them into this tank and dull swimming place. University of North Carolina biologist Ken Loman studies sea turtles that are programed from birth for an extraordinary journey. Mother turtles buried the eggs on the beach and then returned to the sea and the eggs hatch about 50 to 60 days later. Support for the National Science Foundation, Loman is learning 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 likely die, swept into frigid North Atlantic waters. In one lab test turtles responded to magnetic field similarly to what they would encounter off the coast of Florida. The great majority of them turned South East. This is an exciting finding because southeasterly orientation in this part of the world would presumably take turtles further into the Gulfstream. So, the turtles actually have what might be considered accrued global positioning system that is based on the Earth’s magnetic field. And check out this experiment. These turtle moves may look odd. The turtles will actually act out their swimming behavior in air. But this wave simulator re-creates the first environmental cue hatchling turtles respond to. Swimming into waves is a highly reliable trick that the turtles used to guide themselves offshore.