Aquatic Species at Risk - The Narwhal
Species - Details
SARA Status: Under consideration
COSEWIC Status: Special Concern (May 2005)
Region : Arctic
Did You Know?
While it is hard to see for great distances in the ocean, sound travels well. Narwhals, like other toothed whales, have evolved complex and sophisticated systems using sound to investigate their environment and to find food.
The narwhal can create ‘click’ and ‘whistle’ sounds, probably by controlling passage of air between chambers near the blowhole, as is know to be done in other odontocete species. These sounds may then be reflected off the sloping front of the skull. The sounds may then be further focused by the melon, the round space on the head filled with a special mix of blubber oils, and can be altered in shape under muscular control. Clicks and ‘knock’ sounds can come slowly, like knocks on a door. Faster sequences sound like a stick on a picket fence, and can also come in very rapid succession, producing a kind of trumpet blare or the sound of a squeaking door.
This species has been identified as Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). It is currently being considered for listing under the federal Species at Risk Act (SARA).
Protection is afforded through the federal Fisheries Act. If listed under the Species at Risk Act (SARA), it will be afforded additional protection. Under the SARA, a management plan must be developed for this species.
Narwhals (Monodon monoceros), also known as sea unicorns, are toothed whales in the family Monodontidae. Inuit use a number of words to identify the Narwhal including tuugaalik (with tusk), qirniqtaq qilalugaq (black whale) and allanguaq (with black and white dots). Narwhals have the following characteristics:
- Medium-sized whale with no dorsal fin
- Convex-shaped tail fluke
- Newborns are grey or bluish grey and change to black after weaning; with age, white streaks develop on the underside and flanks
- Adults are white to creamy yellow on the belly and grey-black on the back, the very old, especially males, are almost completely white
- Adults have only two teeth. In most males, the right tooth remains embedded in the skull; the left forms a spiral tusk that can extend over 3 m
- Females with a tusk, males with no tusk, and two tusks are rare occurrences
- Newborns weigh about 80 kg and are 1.6 m long
- Adult males can reach 5.4 m in length and about 1,935 kg in weight; females 4.9 m and about 1,552 kg
Narwhals live in Arctic waters, generally above 61°N latitude, in Nunavut, west Greenland and the European Arctic. They are rarely seen in the East Siberian, Bering, Chukchi and Beaufort seas. In Canada, two populations have been recognized based largely on summering distribution: the Baffin Bay population and the Hudson Bay population. Together their range extends throughout the eastern Canadian Arctic south to northwest Hudson Bay, west to Viscount Melville Sound and north to the northern tip of Ellesmere Island. Narwhals from the Baffin Bay population occupy the northern portion of this range, and those from the Hudson Bay population occupy the south.
Habitat and Life History
In summer, Narwhals tend to occupy protected, deepwater coastal areas for either calving or feeding opportunities. In the fall and winter, they favour waters that range in depth from 1,000 to 5,000 m. Overall, the quality of the ice habitats, especially areas of open water and the density of pack ice, seems to be a key aspect of habitat selection. Narwhals generally breed in the spring; however, this may vary between years and location. Gestation is between 14 and 15.3 months and calves are weaned at one to two years of age. Females mature between four and nine, and produce their first young between 7 and 13 years. Males are thought to mature later between 11 and 16 years. The oldest animals may reach 50 years of age but the average lifespan is likely less than 30. Narwhals have a pronounced migratory cycle.
The diet of the Narwhal varies with season and location. They consume mostly fish, Turbot (Reinhardtius hippoglossoides) and Arctic Cod (Boreogadus saida), and squid and other invertebrates including octopus and crustaceans. In spring, Narwhals take Cod at the sea-ice edge. In summer, their foraging intensity declines and food consumption is at a minimum. Foraging intensity resumes in the fall as whales move south, and peaks during the winter.
Factors impacting Narwhal populations in Canada include hunting, contaminants (mercury and cadmium), industrial activities such as commercial fishing, and climate change. The commercial Turbot fishery may also impact the Narwhal since these animals feed almost exclusively on Turbot in the winter. The effects of most of these factors may be mitigated by the Narwhal’s preference for deep water and its widespread distribution.
There are no similar species.
Text Sources: Stewart 2005 (COSEWIC Status Report).
For more information, visit the SARA Registry Website at www.SARAregistry.gc.ca.
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