Secrets of the ocean: why do turtles dance?
Loggerhead turtles travel thousands of miles from where they are born to foraging locations then return again to lay eggs. A new study shows how they do it.
Sea turtles, along with birds and salmon, are known to migrate over vast distances using the Earth’s magnetic field lines. It is believed that they use them both as a compass in order to figure out their heading as well as to create a map enabling them to determine specific geographical positions.
However, for them to be able to do this they must learn the specific magnetic signatures of geographical areas, something that has been “speculated for decades.” Now a new study led by Kayla Goforth of the University of North Carolina at Chapel Hill provides the first “direct evidence” that loggerhead sea turtles can learn and remember these magnetic signatures.
This “fills in an important gap in our knowledge,” said Goforth. Loggerheads spend decades in the open ocean while they mature traveling thousands of miles from their birthplace. However, once they reach adulthood around 35 years of age, they are able to return beaches on the other side of the ocean to within tens of miles of their birthplace.
The secret behind why sea turtles dance
The findings from the study published in the journal Nature suggest that the turtles use two different forms of “magnetoreception.” One allows the turtles to make a map while the other provides their inner compass both of which appear work independent of each other.
The researchers conducted controlled experiments where young loggerhead turtles were put into tanks that were surrounded by magnets which replicated the magnetic fields of two different locations. The turtles were only fed when one of the magnetic fields was present.
When they were in the rewarded magnetic field the turtles would dance providing “strong evidence” that they had learned the magnetic signature of a specific geographical area. However, the exact mechanism of how they learned the magnetic signature is still a mystery.
The researchers tried to disrupt the magnetic information the turtles were receiving by using radiofrequency oscillating magnetic fields. However, the turtles would still dance when in the reward location magnetic field.
But, the radiofrequency field did cause disruptions in the workings of their inner magnetic compass making them disoriented. This allowed them to reasonably conclude that they are using two different mechanisms for learning a specific geographical location to create an internal map and determining their bearings.
Get your game on! Whether you’re into NFL touchdowns, NBA buzzer-beaters, world-class soccer goals, or MLB home runs, our app has it all.
Dive into live coverage, expert insights, breaking news, exclusive videos, and more – plus, stay updated on the latest in current affairs and entertainment. Download now for all-access coverage, right at your fingertips – anytime, anywhere.