Natural Science

Drone footage shows exactly how narwhals use their massive tusks

For centuries, scientists have wondered what narwhal tusks were for.

Narwals are marine mammals with long tusks protruding forward from their heads. Narwhal tusks found washed ashore on beaches are often cited as evidence giving rise to myths about unicorns and horned dragons.

Scientists were among the first and most interested viewers of new video footage, captured by two drones in Canada’s Tremblay Sound, showing narwhals in the wild. The drones’ operations were sponsored by World Wildlife Fund Canada and by Fisheries and Oceans Canada.

The footage shows narwhals using their tusks to stun Arctic cod by hitting them with quick movements. This stuns the fish, making it easier for narwhals to feed on them by swallowing them whole.

Because narwhals live in remote northern regions, they are rarely studied in the wild. Visual confirmation of their behavior has been hard to come by. Marianne Marcoux, a research scientist for Fisheries and Oceans Canada, says drones are ideal for studying narwhals and other skittish marine creatures. "Drones are very exciting, we can see things we couldn't see before," she said.

Scientists are quick to note that although the footage documents one usage for narwhal tusks, it doesn’t rule out other uses. Long-debated theories that the tusks are used as ice picks, as weapons, in sexual selection, and in echolocation are still possible.

The narwhal tusk is actually a tooth – the left canine tooth. The right canine remains in the mouth. The tusks, which grow only in males, can extend to nine feet long.