(Inside Science) -- The skittish narwhal is nearly impossible for scientists to study up close. But with the help of Inuit whale hunters, a geoscientist and his team have obtained high-quality recordings of narwhal calls, as well as new observations of the whales' behavior.
Since narwhals are so flighty, it’s hard to record their vocalizations when researchers are present. Techniques for recording narwhal calls include tagging the whales with microphones or placing microphones on stationary buoys. Tagging whales is expensive and challenging, as well as stressful for the animal; stationary buoys rely on narwhals swimming by them, which is difficult to predict.
But in Greenland, Inuit people have been getting up close and personal with narwhals in the Bowdoin Fjord for decades in order to hunt them. And Evgeny Podolskiy, a geophysicist at Hokkaido University in Sapporo, Japan, has built a relationship with the locals over years of studying the sounds of the nearby glaciers.
To harpoon a narwhal, “the hunters have to approach it in the most careful way,” Podolskiy said. “This gives us a chance to record the animals in open water from very close distance.”
Podolskiy’s recordings revealed some previously unknown details about the acoustic frequencies of narwhal calls, as well as the surprise that narwhals seem not to mind noise -- as long as it’s natural. The study found that narwhals swim much closer than expected to the underwater edges of glaciers, which are some of the noisiest places in the entire ocean.
While this study took place over a few days, Podolskiy plans to do more long-term studies to answer bigger questions about narwhal behavior.
“For narwhals that are living in sea ice-covered waters, in polar night, with very limited access, there are many questions we don’t know the answers to,” he said. “But if we want to start being able to answer these questions, it’s important to understand what their acoustic signals are telling us. That’s how these supervised observations help us approach the more long-term questions we have about these still not-well-understood animals.”
The study was published April 26 in the Journal of Geophysical Research: Oceans.