Most people are well aware of the fact that salmons travel over incredible distances in order to return to the places where they were born and spawn a new generation. Still, it was only recently when a proper scientific explanation for this rather peculiar animal behavior was found.Thus, this week's issue of the scientific journal Current Biology witnessed the publication of a new study stating that these fish most likely rely on the Earth's magnetic field to guide them on their journey back home.
The researchers who have looked into this issue explain that they have reached this conclusion after analyzing 56 years' worth of data concerning both the migratory routes salmons seem to prefer, and the intensity of the planet's magnetic field in various regions, Science News reports.
Despite the fact that the Earth's magnetic field tends to alter ever so slightly on a yearly basis, it looks like salmons have the ability to memorize the magnetic field of the place where they first entered the ocean as juveniles, and later on use this piece of information as a so-called home address.
Nathan Putman, a post-doctoral researcher currently working with the Oregon State University, commented with respect to these findings as follows:
“These results are consistent with the idea that juvenile salmon imprint on (i.e. learn and remember) the magnetic signature of their home river, and then seek that same magnetic signature during their spawning migration.”
“As the salmon travel that route, ocean currents and other forces might blow them off course. So they would probably need to check their magnetic position several times during this migration to stay on track. Once they get close to the coastline, they would need to hone in on their target, and so would presumably check in more continuously during this stage of their migration,” Nathan Putman went on to add.
Although cases of animals using the Earth's magnetic field in order to get about have been reported before, this is the first time when scientific research has managed to prove that animals have the ability to learn the magnetic field rather than simply inheriting information about it.