The narwhal (Monodon monoceros), or narwhale, is a species of toothed whale that has a large “tusk” from a protruding from its head. It lives in the Arctic waters around Greenland, Canada, and Russia. The narwhal males are distinguished by a long, straight, tusk, which is an elongated upper left canine.
Found primarily in Canadian Arctic and Greenlandic and Russian waters, the narwhal is a uniquely specialized Arctic predator. In winter, it feeds on benthic prey, mostly flatfish, under dense pack ice. During the summer, narwhals mostly eat Arctic cod and Greenland halibut, with other fish such as cod making up the remainder of their diet. Each year, they migrate from bays into the ocean as summer comes. In the winter, male narwhals occasionally dive up to 1,500m in depth, with dives lasting up to 25 minutes. Narwhals mostly communicate with clicks and whistles.
Narwhals normally congregate in groups of about five to ten, and sometimes up to 20 outside the summer. Groups may be “nurseries” with only females and young, or can contain only post-dispersal juveniles or adult males, but mixed groups can occur at any time of year. In the summer, several groups come together, forming larger aggregations which can contain from 500 to over 1000 individuals.
Narwhals can live up to 50 years. They are often killed by suffocation when the sea ice freezes over. Other causes of death, specifically among young whales, is starvation and predation by orcas.
According to Wikipedia, previous estimates of the world narwhal population were below 50,000, narwhals are categorized by the International Union for Conservation of Nature (IUCN) as Nearly Threatened. More recent estimates list higher populations (upwards of 170,000), thus lowering the status to Least Concern. Narwhals have been harvested for hundreds of years by Inuit people in northern Canada and Greenland for meat and ivory, and a regulated subsistence hunt continues.