The narwhal (Monodon monoceros), an iconic whale of the remote Arctic waters, is widely known for its long, spiraled tusk, which is in fact an elongated tooth. The tusk, found predominantly in males and that can grow up to 3 meters in length, is one of nature’s most fascinating features and the inspiration for myths such as the unicorn. It is believed to play a role in competition for mates, including displays of courtship. The tusk may have other uses and its function remains debated, largely because few people have observed how these elusive animals use their tusks in the wild.
Limitations of field observations also mean that little is known about many other aspects of the behavior of this highly gregarious Arctic whale, including social and reproductive behaviors, how they adapt to changes in environmental conditions, or whether narwhals engage in behaviors not directly tied to physical fitness, such as playing.
Using drones, researchers from the Harbor Branch Oceanographic Institute of Florida Atlantic University and the Department of Fisheries and Oceans Canada, in partnership with the Inuit communities of Nunavut in the Canadian High Arctic, present the first evidence that narwhals use their tusks in the wild to investigate, manipulate, and influence the behavior of the fish species Salvelinus alpinus, including applying enough force with the tusks to stun and possibly kill the fish. The researchers captured 17 distinct behaviors, which allowed them to understand the dynamics between the narwhal, its prey, and avian competitors.
The results of the study, published in the journal Frontiers in Marine Science, also reveal the first evidence of probable play, specifically object play, in narwhals, as well as other fascinating insights into narwhal behavior in a changing Arctic. Aspects of narwhal actions, for example, may have also included social learning, and possibly social instruction and differences in personality among individual narwhals. These new discoveries further enrich our understanding of the complex behavior of narwhals.
The results also provide the first reports of interactions among narwhals, fish, and birds, including attempts at kleptoparasitism, a “food thief” situation, between narwhals and the seabird Larus hyperboreus.
“The narwhals are known for their behavior in which two or more of them raise their tusks almost vertically out of the water, crossing them in what may be a ritual behavior to evaluate the qualities of a potential opponent or to show those qualities to potential mates,” explains Greg O’Corry-Crowe, Ph.D., senior author, research professor at FAU Harbor Branch and National Geographic explorer. “But now we know that the narwhal tusks have other uses, some quite unexpected, including foraging, exploration, and play,” he adds.
Environmental changes can introduce new encounters between species
The narwhals displayed remarkable dexterity, precision, and speed of tusk movement, and regularly adjusted to follow the moving target. The tusk, especially the tip of the tusk, was used to probe and manipulate the target through brief contacts, which typically elicited a response from the fish.
“I have been studying narwhals for over a decade and have always been amazed by their tusks,” says Cortney Watt, Ph.D., coauthor and research scientist and team lead at Fisheries and Oceans Canada. “Watching them use the tusks to forage and play is extraordinary. This unique study, in which we set up a remote field site and spent some time filming narwhals with drones, is yielding many fascinating insights and providing a panoramic view of their behavior that we had never seen before.”
This investigation highlights how environmental changes can introduce new encounters between species, challenging Arctic species to adapt.
“Our observations provide clear evidence that narwhals pursue fish and use their tusks to interact directly with the fish and influence their behavior,” says O’Corry-Crowe. “Some of the interactions we saw seemed to be competitive in nature, with one whale blocking or attempting to block another whale’s access to the same prey, while others may have been more subtle, possibly communicative and even affiliative. None appeared to be overtly aggressive,” he notes.
Social behaviors among the whales — such as learning from each other — also suggest that social processes may accelerate behavioral adaptation in response to changes in the Arctic.
“To understand how narwhals are being affected and adapting to Arctic changes, field studies that use innovative and non-invasive tools such as drones are essential to observe them in their natural environment without disturbing them,” emphasizes O’Corry-Crowe.
“Drones provide a unique and real-time view of their behavior, helping scientists collect crucial data on how narwhals are responding to changes in ice patterns, prey availability, and other environmental changes. These studies are fundamental to understanding the impact of global warming on these elusive animals,” he concludes.
