The life of the turtle has always fascinated the world. A recent research has found that the adult female sea turtles are magnetically drawn to the beaches where they were hatched. Reportedly, the sea turtle brain contains small magnetic beads which help them to identify specific magnetic signatures of every individual beach, thus they can find back their way back to their birthplace even after a long sojourn.
“Sea turtles migrate across thousands of miles of ocean before returning to nest on the same stretch of coastline where they hatched, but how they do this has mystified scientists for more than fifty years,” co-author J. Roger Brothers of the University of North Carolina, Chapel Hill, said in a press release.
Their work provides enough evidence that turtles imprint on the unique magnetic field of their birth beach as hatchlings and retrieve this information as adults to return to the same place.
It has been known from previous works that while in the sea, sea turtles firmly depend on Earth’s magnetic field as their guide but the specific mechanisms through which the adult female turtles decide to return to their natal beach was not clear.
In this latest study, the researchers analyzed a 19-year database of loggerhead nesting sites along the eastern coast of Florida. A strong link between the spatial distribution of turtle nests and subtle shifts in the Earth’s magnetic field was established, reported Discovery News. This observation was explained further with suitable example like, when Earth’s magnetic field get shifted; as a result, magnetic signatures of nearby beaches move closer, and when it happens there remain high probability of finding more nests on the same stretch of beach. In years when the magnetic signatures move farther apart, the nests should be more spread out.
And exactly that seem to be the case it reality. When magnetic signatures converged, an average increase of 35% in nesting density was noted and when the signatures diverged, nesting density decreased by an average of 6%.
Successful nesting requires soft sand, the right temperature, the least number of predators, and an easily accessible beach. When combining all these features comes, adult female sea turtle tends to believe mom already made the best choice, a reason that explains why she prefers to hatch on the same beach where she was born.