Why do humpbacks hang out at mountains?

Satellite- tracking studies have shown that humpback whales sometimes break their long migrations at giant underwater mountains, called seamounts. For example, they pause for a few days at La Pérouse seamount between the Indian Ocean islands of Réunion and Madagascar, and in the Pacific, off New Caledonia, they hang around seamounts for a week or more before continuing their southward migration.

It’s not known for sure what humpbacks get up to during these stopovers, but they may feed in the waters above seamounts, which are often thick with plankton and fish. They may also congregate here to mate, using the huge geographical features as meeting points.

Another theory is that male humpbacks use the acoustic properties of seamounts to amplify their songs through the ocean. Perhaps the whales locate the seamounts (which influence the Earth’s geomagnetic field) by means of magnetic mental maps.