Published: August 2007
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In Learn More the National Geographic magazine team shares some of its best sources and other information to expand your knowledge of our featured subjects. Special thanks to the Research Division.
By David A. O'Connor, National Geographic Staff

Did You Know?

The narwhal is a mysterious whale. It lives in the Arctic’s stormy, ice-covered seas, and the males bear an ivory tusk—one source of medieval stories of the unicorn. Compared with other whales, little is known about narwhals. How many are there? Why do they migrate every year? How long do they live? All these questions remain unanswered.

Even their famous tusk remains an enigma. Some researchers think it may serve a sensory function, discerning water pressure and temperature. Other scientists, however, point out that if that were so, female narwhals would surely have tusks as well, but only a small percentage do. These scientists believe that the tusk may serve a display purpose akin to a lion’s mane or a deer’s antlers, body features that play an important role in dominance struggles between males.

Though many questions remain about narwhals, the deep-diving marine mammals have been enlisted to help solve a different puzzle: climate change. The Arctic Ocean is crucial in regulating climate. Changes in its currents and temperature would have dramatic effects on the climate of northern Europe. But the polar ocean is remote and difficult to study, so this summer scientists are planning to attach satellite tags to narwhals. As the whales migrate to their winter feeding grounds, diving a mile deep in search of food, the satellite tags will send back constant streams of data on ocean temperature, salinity, and depth. This will give scientists crucial information from one of the fastest changing parts of the ocean. It is thought that Arctic waters have been warming and have been diluted with fresh water, which would alter currents and perhaps climate.

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