A sea turtle memorizes Earth's magnetic field at the beach it hatched on

Loggerhead turtles imprint on the unique magnetic signature of their natal beach as hatchlings, then use it as a homing beacon years later. Researchers found nesting density rises and falls with subtle shifts in local magnetic field lines, showing turtles can navigate home across an ocean using magnetism alone.

— J. Roger Brothers, Kenneth J. Lohmann, Evidence for Geomagnetic Imprinting and Magnetic Navigation in the Natal Homing of Sea Turtles — Current Biology, 2015