With their long, spiraled tusks, narwhals are among the most distinctive-looking creatures of the ocean. Experts have suggested many possible uses for the narwhals' tusks, but newly released drone footage suggests a surprising and important use for their signature appendage: to hit and stun prey.
As Sarah Gibbens reports for National Geographic, the behavior was captured for the first time on camera by researchers at Fisheries and Oceans Canada and the World Wildlife Fund Canada. Drones flying over the waters of Tremblay Sound, Nunavut captured the whales whacking Arctic cod with their tusks, which immobilized the fish and made them easier to gobble up.
This is the first “definitive … scientific evidence” of narwhal tusk use, according to a WWF Canada statement. Because these so-called “unicorns of the sea.” live in remote Arctic waters, it is difficult for scientists to observe them.
The Narwhal’s impressive tusk is actually a large canine tooth that spirals out from the jaw, as Narjas Zatat writes in the Independent. The tooth contains thousands of nerve endings, allowing the whales to detect subtle movements in the water.
The purpose of this careening canine is not fully understood. Experts have proffered a number of theories about how narwhals might use their tusks—from cracking ice, to spearing fish, to digging on the ocean floor—but “none of these behaviors have ever been observed” writes Kristin L. Laidre, a principal scientist at the University of Washington’s Polar Science Center.
It seems unlikely that narwhals rely on their tusks for survival, since females are tusk-less. So, as Laidre notes, the “scientific consensus is that the narwhal tusk is a sexual trait, much like the antlers of a stag, the mane of a lion or the feathers of a peacock. Males use the tusk to determine social rank and compete for females.”
The new drone footage suggests that the narwhal tusk is deployed in at least one other way. “This provides new insights into the function of the tusk, raises new, interesting questions about the species, and opens new avenues of research into these iconic marine mammals,” WWF Canada said their statement.
The study is also important because it highlights the potential of drones as a tool for scientific research. Aerial observations of narwhals were previously conducted with small planes, Gibbens writes, which do not provide complete views and sometimes scare the narwhals away. Drones can zoom over the narwhals without disturbing them, offering a rare glimpse of this mysterious marine mammal.
An exhibition exploring the mysterious narwhal in depth will open at Smithsonian's National Museum of Natural History on August 3, 2017.