magnetoreception

A hatchling loggerhead sea turtle that has never left its home beach swims in the right direction inside a tank where the only clue is an artificial magnetic field. Here is how animals read Earth's magnetic field, which explanations have the best evidence, and which parts of the story are still contested.

A bar-tailed godwit flies 11,000 km non-stop from Alaska to New Zealand. How animals navigate across hemispheres remains one of biology's great mysteries.