Narwhals have fascinated people for centuries. Originally declared as a mythical creature, the secrets surrounding this highly specific species of toothed whale have only been opening up for a few decades. However, despite the use of state-of-the-art technology, our knowledge of the way of life of narwhals is very incomplete. Now, an international team of researchers in northwest Greenland has had the rare opportunity to record and associate various sounds that narwhals can produce with their behavior. The scientists received strong support from local Greenlandic hunters.
Researchers Evgeny Podolskiy and Shin Sugiyama took the opportunity to record the sounds with the hunters at Bowdoin Glacier. Evgeny Podolskiy actually is a geophysicist and has been working in the region for some time on the soundscape of glaciers, especially with active glaciers, in order to be able to predict calving events. “I realized that working in the region and literally not not noting the elephants in the room, namely the endemic legendary Arctic unicorns that swam at our glacier, would be a very big mistake,” explains Podolskiy, who works at Hokkaido University in Sapporo, Japan. The result of the fundamental study is a unique insight into the soundscape and the corresponding behaviour of the narwhal. “Their world is the soundscape of this glacier fjord,” Podolskiy continues. The rsulting paper has now been published in the Journal of Geophysical Resarch.
The team was able to show that the narwhals in the Bowdoin Glacier region are swimming much closer to the glacier front than previously thought. The animals approach the fronts for up to a kilometer. Glacier fronts are very noisy and active areas, but also very productive areas, because water transports numerous nutrients from the glacier into the sea and thus increases productivity. “There’s so much noise down there because of breaking ice and air escaping from bubbles, it’s like a bubble bath underwater,” says the researcher. But the high productivity also attracts fish, which in turn calls the narwhals to the plan. In their study, the scientists were able to record different types of noise. These included click sounds related to hunting. The closer the whales got to their prey, the faster these sounds became, at the end of which they resembled a chainsaw. “If you approach these fast fish and target them, it is better to know where they are; you have to gather this information more often,” Podolskiy explains.
The fact that the researchers were able to record the sounds in the first place is due to the hunters from the Qanaaq region, who come to the fjord every year to hunt narwhals. Normally, narwhals are very shy and hard to observe, let alone to study. But the Inuit in Canada and the Greenlanders know exactly how to approach the animals without scaring them. Because narwhals are an important food source and the skin of the narwhals, which is called mattak, provides necessary vitamin C in a region where no citrus fruits are available and where food in the supermarket is horrendously expensive. As a result, Podolskiy and his colleagues were able to benefit from the experiences and collaboration of the locals and thus gain a rare insight into the world of narwhals.
Source: American Geophysical Union / Podolskiy and Sugiyama (2020) J Geophys Res Oceans 125(5)
Link to the study: Podolskiy and Sugiyama (2020) J Geophys Res Oceans 125(5)
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