The migratory animals They use a wide range of tricks to be able to orient themselves on immense distances and not get lost in the middle of the ocean or in the nowhere of the sky. Among these, the use of Earth’s magnetic field As a point of reference it is one of the most mysterious: we know that many animals (birds, salmon, lobsters…) they use it, but the mechanism below is not clear to us.
Now a study published on Nature adds a name to the list of animals that perceive the magnetic field of the planet: the sea turtles, That not only surf the lines of the field, but are also able to build a mental map of their favorite places.
There is a fundamental novelty in what we discovered on the marine turtles of the species Caretta Carettaalso widespread in the Mediterranean. Normally, in fact, the animals that use the earth’s magnetic field to orient themselves exploit it to maintain the right direction during a migration: it is a general director who works as a sort of inner compass.
The ocean in a tub. Testing in special tanks surrounded by coils that simulated the magnetic conditions of the Atlantic Ocean, the sea turtles have also shown that they can learn the “magnetic signature” of a single geographical area – and they did it by dancing.
As you can see in the video above, the sea turtles dance and beat their legs enthusiastically when they know that they are in an area where food is located. This, according to the authors of the study, is proof that they know how to memorize the position of a restricted geographical area based on its magnetic properties.
Chemical mechanism. Not only that: their “inner compass”, shared with many other species, works according to a chemical mechanism; Their ability to map the individual areas, however, is governed by … something else, which we have not yet managed to identify.
In short, the study shows that sea turtles have not one, but two different magnetic senses, which work differently; The next step will be to find out if the same goes for other aforementioned migratory animals: fish, birds …
