Loggerhead turtle. Photo by Brian Gratwicke.

In the award-winning CD Ask the Planet, the song Wise Like You asks three species to share their secrets. Today we focus on the tortuga, which is a Spanish word for turtle. Amy Martin’s lyrics go,

“And tortuga I know you-a been swimming / In our beautiful seas since dinosaur times / How do you find your way back home / After you roam the globe / If we sit at your knee will you tell us a story or two?”

The tortuga isn’t any particular species, but Amy told us that when she wrote this song, she was thinking about sea turtles, which fascinate her and have earned her respect. We’re going to focus on the loggerhead turtle because it nests over the broadest geographical range of any sea turtle, and there’s been some great research done on how they navigate across vast ocean expanses. For example, researchers at the University of North Carolina at Chapel Hill have put together an informative website about loggerhead turtle migration and navigation.

Which came first, the turtle or the egg? Let’s start with the egg, buried in the sand on a beach. When the hatchlings emerge, they dig their way to the surface and head to the ocean, apparently using reflected moonlight as a guide. They first use wave direction to head out into the ocean, then magnetic cues to navigate to feeding areas on the open ocean.

As adults, sea turtles can migrate 100s to 1000s of miles from their feeding grounds to the very beach they hatched from, with the goal of laying eggs. Navigating to a particular spot is an amazing feat. Again, the theory is that they use magnetic cues to annually navigate to and from nesting areas.

Besides the University of North Carolina website, there are other websites for learning about sea turtle migration, including the Sea Turtle Conservancy which has an educators’ corner, and WildlifeTracking.org.