Narwhal tusks have long fascinated Inuits but there has never been scientific evidence for how they are actually used. Well, drone footage has finally confirmed one use of these strange extensions. In a short clip, a narwhal is shown striking, stunning, and eating a small fish — the first time such behavior has been captured on tape.
“We know narwhals come in an out of the fjords in the summer but its not totally clear what they do,” said Marianne Marcoux, one of the scientists who worked on the study. “The drone allows us to get a new vantage point without disturbing the animals.”
Initiated as a pilot study to test the usefulness of the drone, the goal was to count how many narwhals were entering Tremblay Sound, Nunavut. The research team from Fisheries and Oceans Canada (DFO), World Wildlife Fund Canada, the Vancouver Aquarium, and Arctic Bear Productions got a surprise.
“We found the narwhal would use the tusk to tap fish and it would stun them a little bit, and the narwhal could then suck in the fish,” Marcoux said.
Stunning fish is now an acknowledged secondary function of the tusk — the first of which is for sexual selection. “Its a bit like the feathers of the peacock in that it allows the female to judge the male on his qualities,” Marcoux said.
This secondary function is closely related to another hypothesis, which suggests the tusks are used as sensory organs.
The narwhal’s tusk is a hollow canine tooth that spirals out from the animals head, reaching lengths of up to nine feet. A nerve runs through its middle and small holes enables the narwhal to sense its environment, such as electricity generated by fish.
Despite their apparent noise, the drones dont seem to disturb the narwhals. Marcoux said at least one other study has measured drone noise above and below water in the environments and determined that the devicesweren’t loud enough to bother the animals. The researchers plan to return with a drone next year summer to observe moms and their calves.