Narwhal (Monodon monoceros)

Also known as: narwhale, unicorn whale
  
French: Narval
Spanish: Narval
KingdomAnimalia
PhylumChordata
ClassMammalia
OrderCetartiodactyla
FamilyMonodontidae
GenusMonodon (1)
SizeHead-to-tail length: 400 – 500 cm (2)
Male tusk length: 150 – 267 cm (3)
Length at birth: 150 – 170 cm (4)
Weight at birth: 80 kg (4)
Weight800 – 1600 kg (2)
Top facts

Classified as Near Threatened (NT) on the IUCN Red List (1) and listed on Appendix II of CITES (5). It is also listed on Appendix II of the Convention on Migratory Species (CMS or Bonn Convention) (6) and on Appendix II of the Berne Convention on the Conservation of European Wildlife and Natural Habitats (7).

Famous for its unicorn-like single tusk, narwhals have inspired legends in many cultures and are still revered across the world. The smooth, white tusk is normally found only on males and is the result of extreme growth of the left elongated maxillary tooth that protrudes through the upper lip in a spiral form. It is believed by the majority of the scientific community that the tusk is a secondary sexual characteristic (8). Females occasionally grow a tusk and males have been seen with two, or none. The largest tusk ever measured was a massive 267 centimetres. Narwhals have a conical body shape and flexible neck with a mottled blue, black, grey and white body fading onto the underside. Older males can be distinguished by their white bodies with mottling only on the top of the back. The dorsal fin is just a low, inconspicuous ridge and the tail fin is concave (3).

The narwhal occurs patchily throughout Arctic waters and in the north Atlantic Ocean. The highest narwhal density is found in the eastern Canadian Arctic Ocean and Greenland. It is also found in the waters of Iceland, Svalbard in Norway, Alaska (US), and Russia (3).

Although traditionally thought of as deep-water cetaceans, narwhals actually forage at all depths, remaining close to the pack ice of the Arctic Ocean (3).

Narwhals live in groups of two to ten individuals which may congregate with other groups to form herds of hundreds of individuals (3). They move very slowly and erratically when hunting, searching for fish, squid and shrimps during dives of between 7 and 20 minutes. They are very vocal, clicking and squeaking whilst travelling. Like many cetaceans, surfacing narwhals slap their flippers against the surface and raise their heads and tusks out of the water (9). Narwhals are thought to migrate annually and in very large groups, moving to spend the winter within the heavy pack ice of the Arctic. Predators of narwhals include Greenland sharks, orcas, polar bears, and walruses (3).

Mating takes place between March and May and gestation lasts around 15 months, with births in July and August of the following year. The calves are born tail first and males do not grow their tusks until they have been weaned at around one year of age. Females give birth just once every three years (3).

Hunted by the Inuit as a subsistence food, narwhals are also hunted for their ivory tusks which are sold as curios or to be carved. The price of narwhal ivory has increased significantly since the 1970s and continues to rise. Narwhals are also susceptible to climate fluctuations and long-term climate change, and as pack ice recedes, their range declines. Narwhals are known to have been trapped under fast-forming ice, preventing them from forming a breathing hole (3).

In 1976 the Narwhal Protection Regulations were produced as part of the Canadian Fisheries Act. It contained legislation that required fishing to be limited to quotas, conferring total protection onto mothers and calves, requiring that full use be made of narwhal carcasses, and requiring the full labelling of every tusk obtained. However, these regulations are sometimes poorly enforced. The narwhal is protected in the United States, although the Inuit are exempt from these laws for subsistence hunting only. It is fully protected in Russia and Norway (3), and quotas limit the catch in west Greenland (8). Laws requiring the declaration of narwhal catch, both intentional and by-catch, are necessary throughout this species’ range (3).

To learn more about the conservation of the narwhal and other whales and dolphins see:

Authenticated (07/03/08) by Dr. Mads Peter Heide-Jørgensen, Senior Scientist, Greenland Institute of Natural Resources.
http://www.natur.gl/Default.asp?lang=dk&num=334

  1. IUCN Red List (November, 2008)
    http://www.iucnredlist.org
  2. Macdonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, Oxford.
  3. Culik, B.M. (2002) Review on Small Cetaceans: Distribution, Migration and Threats. UNEP/CMS Secretariat, Bonn, Germany. Available at:
    http://www.cms.int/reports/small_cetaceans/index.htm
  4. MarineBio.org (April, 2005)
    http://marinebio.org/species.asp?id=336
  5. CITES (April, 2005)
    http://www.cites.org
  6. CMS (April, 2005)
    http://www.cms.int
  7. Berne Convention (April, 2005)
    http://www.coe.int/t/dg4/cultureheritage/conventions/bern/default_en.asp
  8. Heide-Jørgensen, M.P. (2008) Pers. comm.
  9. Cetaceans of the World (May, 2005)
    http://www.sci.tamucc.edu/tmmsn/29Species/MoreSpec/narwhal.html