The result that magnetic-field detection might have evolved separately for the map and compass senses bolsters growing evidence for dual magnetoreception systems in other vertebrates 1, 3.

Loggerhead turtles “dance” when exposed to food-associated magnetic fields, and their magnetic map may help them return to specific areas after long migrations.

"The magnetic field," the researchers wrote in their paper, "may provide dogs with a 'universal' reference frame, which is essential for long-distance navigation, and arguably, the most important ...

The magnetic compass always points toward “true north,” based on the Earth’s gravitational field. It’s a relatively unchanging constant that the ship can reliably steer by.