Each year the Lohmann’s study 16 of Bald Head Island’s hatchlings, following their migration patterns and trying to learn how a hatchling born on Bald Head can spend 20 years and 10,000 miles spanning the entire ocean, only to return to our precious island, when they are fully mature.
Dr. Kenneth Lohmann says they learn their “address” upon birth, describing the turtles as magical.
“These turtles are genetically programmed to respond to different magnetic fields. They are sensitive to the Earth’s magnetic field and can sense the very subtle differences that vary with location,” he says.
These magnetic fields keep the turtles on their migratory path. Dr. Catherine Lohmann says the nesting beaches tend to slightly alter due to weather changes such as hurricanes, but the turtles always return very close to home.
“They remember the magnetic field of their home beach and they come back to nest at the magnetic field they remember,” she says. “In general, the turtles know, I was born there, I grew up there, it worked for me and it will work for my offspring.”
Bald Head Island’s beaches are prime nesting area for turtles, the island’s uniqueness comes into place for making it the perfect place for sea turtles to lay their eggs. It’s soft sand, wide open beaches, warmth and lack of predators all come into play to make the island so popular for sea turtles.
Scientists are able to determine that the same turtles return year after year through genetics. The turtles return to their home beach or one very close. The Lohmanns say they aren’t exactly sure as to when the turtles imprint on their birth place, it could be as early as when they are still eggs in the sand.
In their lab at UNC, the Lohmann’s have built a device that can mimic the magnetic field of different places. They use it to learn how turtles react when given magnetic fields of Bald Head of the Bahamas or even Canada. They put the device around a large pool of water and tether a turtle inside the pool. A small ‘swimming’ suit is placed on the turtles and attached by a thin fishing line to electronics that can tell the direction the turtles want to swim. The turtles will continue to swim feeling no restraint, in any direction they want, though they never reach the side of the pool. The Lohmanns then are able to slightly alter the magnetic field and gather data for their study.
This summer all 16 of the turtles will be released into the Gulf Stream and the Bald Head Island Conservancy will be selling opportunities to spend a day at sea on a charter boat to have the experience of a lifetime, releasing the turtles. The BHI Conservancy will also allow opportunities to visit the turtles at the Lohmann lab and learn all about their unique personalities.
If you are interested in the experiences you can contact Melissa Blackmon at /Blog/276380/Bald-Head-Turtles-Leading-Scientific-Research.