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In a first, scientists have studied and captured footage of the iconic narwhals of the Arctic using their tusks to hunt. They also assessed how the toothed whales are living in a warming, changing Arctic.
The narwhal (Monodon monoceros) lives in remote Arctic waters. Males are known for their long, spiral tusks, which is really an elongated tooth.
It is believed that the tusk plays a role in competition for mates, including mating displays. It may have inspired myths such as the unicorn. But other uses of the tusk are not clear since few people have observed these elusive animals in the wild.
Researchers from the Florida Atlantic University’s Harbor Branch Oceanographic Institute, and Canada’s Department of Fisheries and Oceans, in partnership with Inuit communities in Nunavut in Canada’s High Arctic, used drones to provide new insights into narwhal behavior.
They found that narwhals used their tusks in the wild to investigate, manipulate and influence the behavior of Arctic char (Salvelinus alpinus), including delivering sufficient force with their tusks to stun and possibly kill the fish.
The narwhals exhibited remarkable dexterity, precision and speed of movement of the tusk, and regularly made adjustments to track the moving target. The tusk, especially the tip of the tusk, was used to interrogate and manipulate the target by brief contacts, which typically elicited a response from the fish, noted a statement by the Florida Atlantic University.
Researchers captured 17 distinct behaviors, which shed light on the dynamics between the narwhal, its prey and avian competitors.
There was also a documentation of interactions between narwhal, fish and birds, including attempted kleptoparasitism, a “food thief” situation, among narwhals and glaucous gulls (Larus hyperboreus).
They also found evidence of narwhals at play, specifically exploratory-object play. Other behavioural aspects documented include social learning, and possibly social instruction and personality differences among individual narwhal.
“Narwhals are known for their ‘tusking’ behavior, where two or more of them simultaneously raise their tusks almost vertically out of the water, crossing them in what may be a ritualistic behavior to assess a potential opponent’s qualities or to display those qualities to potential mates,” the statement quoted Greg O’Corry-Crowe, senior author of the study and a research professor at FAU Harbor Branch and a National Geographic Explorer. “But now we know that narwhal tusks have other uses, some quite unexpected, including foraging, exploration and play.”
He added that drones provided a unique, real-time view of narwhal behaviour, helping scientists gather crucial data on how the whales 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,” O’Corry-Crowe added.
The study has been published in the journal Frontiers in Marine Science. Study co-authors are Maha Ghazal, Mark Gillespie and Luke Storrie, Fisheries and Oceans Canada; and Paul Galvin and Jason Harasimo, World Wildlife Fund, Canada. Watt also is an adjunct professor at the University of Manitoba.