Narwhal

The narwhal, or narwhale (Monodon monoceros), is a medium-sized toothed whale and possesses a large "tusk" from a protruding canine tooth. It lives year-round in the Arctic waters around Greenland, Canada, and Russia. It is one of two living species of whale in the Monodontidae family, along with the beluga whale. The narwhal males are distinguished by a long, straight, helical tusk, which is an elongated upper left canine. The narwhal was one of many species described by Carolus Linnaeus in his publication Systema Naturae in 1758.

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 polar cod making up the remainder of their diet. Each year, they migrate from bays into the ocean as summer comes. In the winter, the male narwhals occasionally dive up to 1,500 metres (4,900 feet) in depth, with dives lasting up to 25 minutes. Narwhals, like most toothed whales, communicate with "clicks", "whistles", and "knocks".

Narwhal
  • Size

    Narwhals are medium-sized whales, and are around the same size as beluga whales. Total length in both sexes, excluding the tusk of the male, can range from 3.95 to 5.5 m (13 to 18 ft). Males, at an average length of 4.1 m (13 ft 5 in), are slightly larger than females, with an average length of 3.5 m (11 ft 6 in). Typical adult body weight ranges from 800 to 1,600 kg (1,800 to 3,500 lb). Male narwhals attain sexual maturity at 11 to 13 years of age, when they are about 3.9 m (12 ft 10 in) long. Females become sexually mature at a younger age, between 5 to 8 years old, when they are around 3.4 m (11 ft 2 in) long.

  • Feeding

    Narwhals have a relatively restricted and specialized diet. Their prey is predominantly composed of Greenland halibut, polar and Arctic cod, cuttlefish, shrimp and armhook squid. Additional items found in stomachs have included wolffish, capelin, skate eggs and sometimes rocks, accidentally ingested when whales feed near the bottom.Due to the lack of well-developed dentition in the mouth, narwhals are believed to feed by swimming towards prey until it is within close range and then sucking it with considerable force into the mouth. It is thought that the beaked whales, which have similarly reduced dentition, also suck up their prey.

  • Life History

    Females start bearing calves when six to eight years old. Adult narwhals mate in April or May when they are in the offshore pack ice. Gestation lasts for 14 months and calves are born between June and August the following year. As with most marine mammals, only a single young is born. The newborn calves begin their lives with a thin layer of blubber which thickens as they nurse their mother's milk which is rich in fat. Calves are dependent on milk for around 20 months. This long lactation period gives calves time to learn the skills they need for survival. Mothers and calves stay close and when travelling, the calf stays by its mother's back for assistance in swimming. Narwhals can live up to 50 years old.

  • Behavior

    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 ("bulls"), 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. At times, bull narwhals rub their tusks together, which is known as "tusking". This is thought to maintain social dominance hierarchies or maintenance of the tusk as a sensitive sensory organ.