![]() ![]() Moreover, the field is present everywhere on and near the planet, from the highest altitude where windborne microbiota are lofted to the deepest trenches of the sea. Although the geomagnetic field has waxed, waned, and shifted over time, it has been present continuously for as long as organisms have existed. ![]() Despite recent progress, much remains to be learned about the organization of magnetic maps, how they develop, and how animals use them in navigation. Recent findings also indicate that sea turtles, salmon, and at least some birds imprint on the magnetic field of their natal area when young and use this information to facilitate return as adults, a process that may underlie long-distance natal homing (a.k.a. ![]() Diverse animals ranging from lobsters to birds are now known to use magnetic positional information for a variety of purposes, including staying on track along migratory pathways, adjusting food intake at appropriate points in a migration, remaining within a suitable oceanic region, and navigating toward specific goals. In less than a generation, the idea that animals use Earth’s magnetic field as a kind of map has gone from a contentious hypothesis to a well-established tenet of animal navigation. In addition to providing animals with a source of directional or ‘compass’ information, Earth’s magnetic field also provides a potential source of positional or ‘map’ information that animals might exploit to assess location. ![]()
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