For centuries, suspicions over just what the narwhal does with its tusk have been long-held, giving way to many a myth and a great deal of speculation along the way. 

Despite being one of the most iconic marine mammals, little is actually known about the life and habits of this fascinating species of whale inhabiting the remote waters of the Arctic – and we have even less insight into just how it goes about using its tusk on the day to day.

That is, until now. Because researchers from Florida Atlantic University’s Harbour Branch Oceanographic Institute and Canada’s Department of Fisheries – working in partnership with Inuit communities in Nunavut in Canada’s High Arctic – have now captured what they call ‘the first evidence’ of what their mysterious ‘tusking’ behaviour involves… and they’ve been pleasantly surprised.

From foraging and investigating potential food objects to simply ‘playing’ for the sheer fun of it, researchers observed no fewer than 17 distinct behaviours among narwhals, shedding new light on the dynamics between the narwhal, its prey, and even the odd avian competitor.

The narwhal’s tusk is a thing of legend. A spiralling, elongated tooth, the tusk is predominantly found in males and can grow up to 10 feet long. Owing to limited observations of the mammal in its Arctic habitat, it’s a long-held belief that the tusk’s primary role within the competitive behaviour between males in their attempts for a mate. 

However, observing footage captured using drones, researchers have now provided the first recorded evidence of narwhals using their tusks in the wild to investigate, manipulate, and influence the behaviour of Arctic char, including delivering sufficient force with their tusk to stun and possibly kill the fish.

Results of the study, published in the journal Frontiers in Marine Science, have also revealed the first evidence of likely play, specifically what the researchers have called ‘exploratory-object play’, as well as other fascinating insights into narwhal behaviour in a changing Arctic.

They report that aspects of the observed narwhals’ actions also included social learning and maybe even offering instruction while showcasing personality differences among individuals. Among the report are first recorded interactions between narwhal, fish, and some birds, recording instances in which narwhals had to ‘fend off’ potential food thieves of the avian variety.

“Narwhals are known for their ‘tusking’ behaviour, where two or more of them simultaneously raise their tusks almost vertically out of the water, crossing them in what may be ritualistic behaviour to assess a potential opponent’s qualities or to display those qualities to potential mates,” said Greg O’Corry-Crowe, Ph.D, a research professor at FAU Harbour Branch, a National Geographic Explorer, and senior author on the study.

“But now we know that narwhal tusks have other uses, some quite unexpected, including foraging, exploration, and pay.”

The study has suggested that the narwhals observed exhibited ‘remarkable dexterity, precision, and speed of movement’ of the tusk, making regular adjustments to track their moving targets. Meanwhile, they typically used the tip of their tusk to interrogate or manipulate the target by brief contacts, usually provoking a response from the fish.

“I have been studying narwhal for over a decade and have always marvelled at their tusks,” said Cortney Watt, Ph.D, co-author and research scientist and team lead at Fisheries and Oceans, Canada. “To observe them using their tusks for foraging and play is remarkable.

“This unique study where we set up a remote field camp and spent time filming narwhal with drones is yielding many interesting insights and is providing a bird’s eye view of their behaviour that we have never seen before.”

The research has also highlighted how environmental changes might introduce new interspecies encounters, challenging Arctic species to adapt. This includes the way in which narwhals use their tusks to chase fish to influence their behaviour. 

“Some of the interactions we saw appeared competitive in nature with one whale blocking or trying to block another whale’s access to the same target fish, while others may have been more subtle, possibly communicative and even affiliative,” said O’Corry-Crowe. “None appeared overtly aggressive.”

Social behaviours among the whales – such as learning from one another – also suggest that social processes could speed up behavioural adaptation in response to Arctic changes.

O’Corry-Crowe, continued: “Drones provide a unique, real-time view of their behaviour, helping scientists gather crucial data on how narwhals are responding to shifts in ice patterns, prey availability, and other environmental changes. Such studies are key to understanding the impact of global warming on these elusive animals.”

The research paper – Use of tusks by narwhals, Monodon monoceros, in foraging, exploratory, and play behaviour – was co-authored by Maha Ghazal, Mark Gillespie, and Luke Storrie at Fisheries and Oceans Canada; and Paul Galvin and Jason Harasimo, World Wildlife Fund, Canada.

The research was supported by Fisheries and Oceans Canada, the National Geographic Society, the World Wildlife Fund Canada, and the Nunavut Wildlife Management Board.

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