Animal Magnetism: How Salmon Find Their Way Back Home Before
they end up filleted and sautéed on your dinner plate, salmon
lead some pretty extraordinary, globe-trotting lives. After
hatching in a freshwater stream, young salmon make a break for
the ocean, where they hang out for years, covering thousands of
miles before deciding its time to settle down and lay eggs in
the same stream they were born. So how do these fish find their
way back to their home river? According to one theory, it's all
about magnetism. When salmon are young, the theory goes, they
imprint on the pattern of the Earth's magnetic field at the
mouth of their native river. Years later, when the salmon head
back home to spawn, they home in on that pattern. In a study
published Thursday in Current Biology, the scientists behind
that theory now say they have evidence that's exactly how the
fish are navigating. Magnetic detection "is one part of their
toolkit for being really efficient navigators," says the study's
lead author, Nathan Putman,