Narwhals

Monodontidae

Narwhals belong to a group called Monodontidae which is a family of small whales that have been around since the time of the Miocene. There are two living members of Monodontidae which are Narwhals and Beluga Whales. Narwhals and Belugas are actually related close enough that they can interbreed with each other, but this is extremely rare. In 1990 a skull was found and no one really new what animal it belong to until 2019 when a DNA test was ran and it turned out that it was a hybrid.

Diet

Narwhals have a diet of mostly arctic cod, green halibut, cuttlefish, flatfish, squid, and some crustaceans. Like many cetaceans, they use echolocation to locate their food. But Narwhals have a weird way of eating. Since they don't have any teeth in their mouth they just suck up their food.

What's the big tusk for?

All males have a tusk and only 15% of females have a tusk. And some tusks can get up to 10 feet long. The Tusk is a large canine tooth. There are actually two tusks in the Narwhals skull but the left one is the large tusk and the right one stays in the skull and never really comes out. Every once in a while it does though. And about one in 500 males have two tusks. There has also been one known case of a female that had two tusks.

But what was it used for? The tusk has thousands of little holes in its tusk and nerves on it. When seawater goes into the holes which leads it to the sensory center at the base of it. And this is what tells the brain all about the water around them. So they can sense the temperature of the water the amount of salt. They probably use this the most when they are migrating. It is also possible that it is used to display to potential mates.

Migration and Mating.

Narwhals mate in April or May while they are under the offshore pack ice. Then they migrate to ice free water in the summer and that's when the babies are born. They usually live in packs of 5 to 10 and sometimes even up 20. In the summer lots of groups combine into a group of 500 to 1,000 individual Narwhals.

Communication and Echolocation

Narwhals vocalize by using sounds like clicks, whistle, and knocks. These sounds are created through a chamber in the blowhole that moves air to make the sound. It is also possible that each individual Narwhal group may have there own specific calls. Narwhals also use echolocation for detecting prey and finding barriers in short distances.

Diving

Narwhals make some of the deepest dives ever recorded of any marine mammals. The longest recorded Narwhal dive was about 2,600 (800 ft) meters but they usually dive from within 30 to 300 meters, and they dive down at least 15 times a day. Narwhals can hold their breath for 25 minutes underwater.

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Image Credit: Allosaurus: "Allosaurus fragilis Marsh, 1877" by Marshall P. Felch is marked with CC0 1.0. KT Extinction Event: "Lava and basalt at Hawaii Volcanoes National Park (2004, Chain of Craters Road) (photograph: Scot Nelson)" by Plant pests and diseases is marked with CC0 1.0. Livyatan: Cam Dillon.