Narwhal

Scientific Classification

Common Name

narwhal, unicorn whale

Kingdom

Animalia

Phylum

Chordata

Class

Mammalia

Order

Cetacea; more recently Cetartiodactyla

Suborder

Odontoceti

Family

Monodontidae

Genus Species

Monodon ("one tooth") monoceros ("one horn")

Fast Facts

Description

Narwhals are perhaps best known for their extremely elongated tusks. They are the only whales that have them. The tusk is a hollow tooth, which always spirals counter-clockwise from the left side of the skull. It can measure 2.5 to 2.7 m long (8 to 9 ft.). Most narwhals have just one tusk, but narwhals with two tusks have been reported. Almost exclusively seen in males, there are only scattered reports of females developing a tusk. Narwhals have no other visible teeth in their jaws. Like the beluga whales, narwhals lack a dorsal fin and instead have a dorsal ridge. Mature narwhals tend to have a black and white spotted coloration the dorsal region of their body, while older narwhals may be almost completely white. Narwhal calves typically are a blotchy gray.

Size

Newborn calves average 1.6 m (5.25 ft.) in length
Male:  Minus the tusk, adult male narwhals measure up to 5 m (16.1 ft.) long
Female: Females are smaller, with a size up to 4 m (13 ft.) in length

Weight

At birth, calves can weigh as much as 80 kg (176 lbs.)
Male:Mature males weigh up to 1,600 kg (3,200 lbs.)
Female:Adult females can reach a weight of up to 900 kg (2,000 lbs.)

Diet

Fish, squid, and shrimp make up the Narwhal’s diet, especially Arctic fish species, such as Greenland Halibut (Reinhardtius hippoglossoides), Arctic Cod (Boreogadus saida), and Polar Cod (Arctogadus glacialis).

Gestation

14 to 15 months

Estral Period

Throughout the winter and spring with a peak in April

Nursing Duration

At least 12 months

Sexual Maturity

Male:  8 to 9 years
Female: 4 to 7 years

Life Span

Up to 50 years

Range

Narwhals primarily inhabit the Atlantic sector of the Arctic and are rare in the Pacific sector. The principal distribution is from the central Canadian Arctic, eastward to Greenland and into the eastern Russian Arctic. They are rarely observed in the far eastern Russian Arctic, Alaska, or the western Canadian Arctic. In summer, narwhals spend approximately two months in high Arctic ice-free shallow bays and fjords and overwinter in offshore, deep, ice-covered habitats along the continental slope.

Habitat

The migrations of narwhals closely follow the movement of loose pack ice. Seasonal distributions are connected by extensive annual migrations (over 1,000 km) which last approximately 2 months.

Population

Global: Total global abundance of more than 170,000 whales, however this does not include Northeast Greenland or the Russian Arctic for which no estimates are available. Ten subpopulations number more than 10,000 individuals, and two subpopulations number more than 35,000. While Narwhals occur broadly in Arctic waters, their distribution, movements, and genetic characteristics suggest the existence of about 12 discrete or semi-discrete subpopulations or management stocks.

Status 

IUCN: Least concern
CITES: Appendix II
USFWS:Not listed

Fun Facts

1. Narwhals and Belugas are the only members of the family Monodontidae.
2. Some theorize that males "joust" with their tusks or use them to poke their way through ice floes or even to skewer prey. These theories are unlikely. If the tusk were damaged, it could lead to severe infections and death for the narwhal. The tusk probably serves as a secondary sexual characteristic for males, indicating which males are older and more mature.
3. Contrary to common belief, narwhals do not spear fish with their tusks, but instead suck prey into their mouth and then swallow it whole.
4. Narwhals travel farther north than perhaps any other whale species. They are well adapted for life in frigid water, with blubber accounting for up to 35% of their body weight for insulation.

Ecology and Conservation

Killer whales and Greenland sharks preyed upon narwhals, but the main enemy of narwhals is man. Since some believe their tusks possess almost magical healing and aphrodisiac properties, they are still illegally hunted today. As with other whales, both national and international laws protect narwhals.

Bibliography

Jefferson, T.J. Leatherwood, S. and M.A. Webber. FAO Species Identification Guide. Marine Mammals of the World. Rome. FAO, 1993.

Leatherwood, Stephen, and Reeves, Randall R. The Sierra Club Handbook of Whales and Dolphins. San Francisco: Sierra Club Books, 1983.

Nowak, Ronald M. (ed.). Walker's Mammals of the World. Vol. II. Baltimore: Johns Hopkins University Press, 1991.

Parker, S. (ed.). Grizmek's Encyclopedia of Mammals. Vol. IV. New York: McGraw-Hill Publishing Co., 1990.

Reeves, R. R., Stewart, B.S., Clapman, P.J., and J.A. Powell (Peter Folkens illustrator). National Audubon Society: Guide to Marine Mammals of the World. New York: Random House, 2002.

http://animaldiversity.ummz.umich.edu

Lowry, L., Laidre, K. & Reeves, R. 2017. Monodon monoceros. The IUCN Red List of Threatened Species 2017: e.T13704A50367651. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T13704A50367651.en. Downloaded on 25 September 2018.

NOAA Fisheries – Narwhal Species Profile. https://www.fisheries.noaa.gov/species/narwhal. Downloaded on 25 September 2018.