Little-known facts about narwhals, wonderful unicorn whales

They live in groups of 5 to 10. During the summer, narwhals migrate closer to coasts and form larger groups – up to 1,000 individuals. They spend winters offshore, feeding in deep waters.

Almost all males and around 15% of females grow a protruding tusk. This spiral horn, often compared to that of a unicorn, is actually a canine tooth. There are millions of nerve endings on the tusk, which makes it a powerful sensory organ. With the help of the tusk, narwhals can detect even the slightest changes in the water, such as temperature, salt level and pressure.

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They don't have well-developed teeth in their mouth, so narwhals usually swallow their prey whole. Their diet is quite monotonous, primarily consisting of cod, cuttlefish, shrimp and squid.

Narwhals are being satellite tagged to track their territorial movements and migration:

The thickness of sea ice decreases every year, making it harder for narwhals to forage. They are considered near threatened. Around 1,000 individuals are killed every year by humans for meat, teeth and skin.

Take a look at this article to find out what's hidden in the depths of the ocean.

With the average lifespan of 40 years, some narwhals live to be 50 years old.

Narwhals can go as deep as 1,500 m (4,500 ft) under water and spend around 25 minutes there.