The narwhal, "unicorn of the ocean," is amongst the world's rarest whales. They are very mysterious and elusive by nature, and their big horn-like tusk gives them a very distinctive appearance. The tusk is, in fact, a tooth that grows out of the male's upper jaw. Adult narwhals typically have black and white spots on the dorsal parts of their body, and older narwhals can be almost entirely white. Calves are typically a blotchy gray.
The narwhal is scattered throughout Arctic waters and the North Atlantic Ocean. Most of them are found in Greenland and the eastern part of the Canadian Arctic Ocean. They forage at any depth, not going far from the pack ice in the Arctic Ocean.
The narwhal is gregarious and commonly occurs in pods of between six and twenty animals, though most groups number between three and eight. These groups often are segregated by sex, and pods of male 'bachelors' are common. The smaller groups generally gather together at migration into herds of hundreds and sometimes thousands. Narwhals remain near pack ice for the whole year. Breathing holes are created through sheets of ice with thrusts of their thick head, sometimes by several of them at the same time. They are very vocal, squeaking and clicking as they travel. Like many cetaceans, narwhals slap their flippers on the water as they surface, raising their tusks and heads out of the water. It is thought that they migrate every year in very large groups, travelling to spend winter amongst the heavy pack ice in the Arctic.
Narwhals are polygynous, an adult male mating with multiple females during one mating season. Mating usually occurs from March to May, when males court the females and compete with one another. The gestation period is around 15 months, with calves being born in July and August the year following. Narwhals give birth to a single calf and they are born tail first. The tusks of males do not grow until they are weaned, when they are about one year old. Young narwhals can swim soon after birth. A female will give birth once every three years. Males generally are sexually mature between the ages of 8 – 10, while females achieve maturity between 4 and 7 years.
Narwhals are hunted for meat, their skin, called "maktaq", and their ivory tusks, sold as curios or for carving. They are susceptible to climate fluctuations as well as long-term climate change. Their range declines as pack ice recedes. They have sometimes been trapped under ice which forms too quickly for them to make a breathing hole. Industrial extraction, marine construction, shipping and military activities cause noise pollution under the water. As narwhals depend on sound for communication, interference by noise pollution may impact their ability to navigate, access food and mates, avoid predators and look after their young.
According to the IUCN Red List, the global narwhal population size is around 80,000 individuals, including estimates for this species in specific regions: Canadian High Arctic - 70,000 animals; northern Hudson Bay - 3,500 animals; West Greenland - over 2,000 animals; East Greenland – fewer than 1,000 animals. The narwhal population is currently classified as Near Threatened (NT) on the IUCN Red List.
Narwhals are at the top of the food chain and have an important role in the overall health of the marine environment, controlling the populations of the prey items they consume.