For the first time, scientists have filmed narwhals using their iconic tusks to stun and hunt fish. This amazing drone footage further supports the hunch that the sea unicorn's signature "face blade" acts less like a sword and more like a multitool. 

The clip was captured by scientists with Fisheries and Oceans Canada (DFO), the University of Windsor, World Wildlife Fund, the Vancouver Aquarium and Arctic Bear Productions during a field project last summer. The team ventured to Tremblay, a sound nestled in the farthest reaches of the Canadian Arctic, to tag and track these elusive whales. 

Despite what many recent headlines would have you believe, the footage doesn't "solve the mystery" or "uncover the use" of narwhal tusks. Instead, the clip is evidence of yet another of the appendage's many uses.

"What's very exciting to me is what else can they do with their tusks?” says DFO team member Marianne Marcoux.

Only male narwhals possess the swirly structure, which is actually a modified tooth (the front left canine). If the tusk were critical to feeding, then we'd expect female narwhals to starve without one. It's more likely that possessing a "stun gun" is a welcome perk for male whales, who rely on the tusk more prominently in other ways. 

It's long been known that the tusk can be used as an ice pick and sparring sword, for example. And a 2014 study added "chemical detection device" to that list as well. 

Unlike most mammal teeth, narwhal tusks are not protected by enamel. They contain a system of channels and tubes that usher in traces of sea water, which, once inside, excite nerves at the centre of the tooth. Researchers suspect that these nerve endings allow narwhals to "taste" for nearby mates, environmental changes and potential prey. 

DFO marine biologist Bob Hodgins notes that it looks like the whales in the footage are able to track the Arctic cod's movements with the tusk as well. 

"It gives us a close enough image to give us these kinds of details of how the animals are feeding and how they're behaving," he says. 

A narwhal is released after the team's workup, which involves taking measurements and blood samples, and fitting the animal with a small transmitter. Image: WWF Canada

Clues about tusk function aside, documenting any feeding behaviour in these waters is also a huge step for conservation. Nearly 90 percent of the world's narwhals can be found in Canadian waters, and until now, we believed they fed exclusively around the southern portion of Baffin Island, where they spend the winter months hunting deep under the pack ice. 

Confirming that they also feed in their summer habitat will help the team push for better protections there in the future. 

"This footage, while also stunning to watch, will play a significant role in the future of narwhal conservation," WWF Canada President and CEO David Miller said in a press release. "As the Arctic warms and development pressure increases, it will be important to understand how narwhal are using their habitat during their annual migration."