Inuit hunters led researchers up a fjord in Greenland in pursuit of mysterious and shy narwhals. The geophysicists were hunting the sounds of the unique marine mammals called the “unicorns of the sea.

You’d think that narwhals couldn’t be more enchanting. These elusive, ice-dodging, deep-diving whales have 10-foot snaggletoothed tusks, and they see with sound. But then there’s the narwhal of east ...

Few scientists have seen the apparent unicorns of the sea brandishing their tusks in the wild. The elongated, spiraled tooth protrudes from the top lip of males and some females, and can grow to ...