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Mammalian Species DISCLAIMER 
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Narwhal (Monodon monoceros)
Like the white whale, its closest relative, the narwhal is confined to the northern extremes of the Northern Hemisphere. The narwhal's habitat requirements seem to be more specific than the beluga's, and thus its range is more restricted. Because both species prey on many of the same types of organisms, they are potential competitors. However, during summer at least, narwhals tend to occupy deep bays and fiords; whereas, white whales congregate in shallow, relatively warm estuaries. The best-known and probably largest narwhal population in the world inhabits the deep inlets, sounds, and channels of the eastern Canadian Arctic and northwest Greenland. The narwhal's highly modified dentition is its most distinctive attribute. Two adult teeth are rooted in the upper jaw. In females, both usually remain embedded, leaving the animal functionally toothless. In males, the left tooth erupts through the gum at the front of the jaw and grows into a straight, tapered, spiralled tusk up to 3 m long. Occasionally, females develop one or two external tusks, and a small percentage of males become "double-tuskers". The function of the male narwhal's formidable tusk has long been debated. It is now generally agreed that the tusk serves a role in aggressive interaction among adult males, although details of the behaviour involved in its use are unknown. Tusk-crossing or "fencing" above and below the surface has been observed. in overall body size and shape, narwhals resemble belugas. In the Canadian Arctic, males reach physical maturity at a length of about 4.7 m when they weigh about 1,600 kg; females at 4.15 m and 1,000 kg. Narwhals are about 1.6 m long and weigh just over 80 kg at birth. The body colour changes with age, from evenly light gray at birth to dark gray or almost black in juvenile stages and mottled at maturity. Adults, especially males, become white ventrally and laterally but retain dark pigment on the back, head, neck, and edges of the flippers and flukes. Very old bulls can be mostly white. The narwhal's summer distribution in Canada is centred in Lancaster Sound and its adjacent waters, including Prince Regent Inlet, Barrow Strait, and Peel Sound, and in Jones Sound. Especially large numbers occur in Admiralty Inlet and the Pond Inlet Eclipse Sound-Navy Board Inlet-Milne Inlet complex, where narwhals have long been hunted by the Inuit. During fall the Lancaster Sound animals migrate south in Baffin Bay, and they overwinter in the broken pack ice or along the edges of fast ice as far south as Disko Bay on the east and Hudson Strait on the west. Narwhals are also found during summer in deep waters of northern Hudson Bay, Hudson Strait, and Foxe Basin; it is not known whether the animals overwinter in these areas and thus comprise a separate resident stock. Rarely, narwhals wander as far south as the coast of Newfoundland. There is some fossil evidence that narwhals were present in the Gulf of St. Lawrence a few thousand years ago. Very few narwhals have been recorded in the western CanadianArctic. Narwhals are gregarious. Pods of three to four or sometimes as many as 20 individuals congregate in close proximity and in this way form herds of several hundred or even thousands of animals. Pods sometimes consist of individuals of the same sex and age, but mixed groups are also seen. During their westward spring migration in Pond Inlet and Lancaster Sound, groups of adult males head the procession, followed by females and young. Later in the summer, narwhals are segregated into groups of immature males, groups of mature females and calves, and groups of tusk-bearing adult males. There is some evidence that the bulls remain farther offshore, while females with calves penetrate far inside embayment where waters are relatively calm. The size of the narwhal population in Canadian waters during summer has been estimated as over 13,000. There is currently no way of knowing how the present population size compares to that of earlier times. In spring (June-July) at the Pond Inlet floe edge, narwhals dive under the fast ice in pursuit of arctic cod, a staple item in their diet. Later, as they move through the inlet toward their main summering grounds, they prey on halibut, shrimp, and squid. Narwhals are deep divers, and the pursuit of squid and halibut probably takes them to depths well below 400 m. Narwhals face many of the same ecological problems as belugas. Killer whales, polar bears, and rarely even walruses attack them. Ice entrapment makes them vulnerable to predation, starvation, or suffocation. The life history of narwhals and belugas appears to be similar in some respects. In the absence of direct evidence, some scientists have estimated the narwhal's vital parameters by inference from the beluga's, since the latter has been more extensively studied. Narwhals breed mainly in mid-April, and most calves are born in mid-July. Lactation probably lasts for well over a year, and the average calving interval is probably three years. Several unsuccessful attempts were made in 1969-1970 to bring live narwhals into captivity. A small orphaned calf from Grise Fiord was airlifted to the New York Aquarium but died after a month of confinement. The Vancouver Public Aquarium captured six narwhals in 1970 and transported them across the continent. All died within a few months, mainly from bacterial or viral infections. Narwhals have been hunted by the Inuit for many centuries, mainly for meat, muktuk, and sinew used as thread. During the eighteenth and nineteenth centuries, the arrival of European and American whalers and merchants made narwhal tusk ivory valuable as a trade commodity. The commercial whalers killed some narwhals themselves, but large amounts of ivory were also bartered from the natives, especially during the first quarter of the twentieth century on north Baffin Island. There are three types of hunt conducted by the narwhal hunters of Pond Inlet: the floe-edge hunt from mid-June to mid-July, the ice-crack hunt from late July to early August, and the open-water hunt in August and September. During the floe-edge and icecrack hunts, the animals are shot by hunters standing on the ice. Carcasses that do not sink are retrieved with the aid of a boat or a harpoon and line. During the open-water hunt, narwhals are chased in outboard powered boats and canoes. Once driven into shallow water, they are shot. Harpoons are sometimes attached to wounded animals to facilitate retrieval. The Canadian government introduced interim Narwhal Protection Regulations under the Fisheries Act in 1971. These made hunting by anyone except the Inuit illegal and set a maximum catch limit of five narwhals per year for each subsistence hunter. In 1976 and 1978 the regulations were made more explicit. Now calves and females accompanied by calves cannot be killed legally, and any part of a narwhal carcass suitable for food is to be utilized fully. Hunters are now required to affix a tag to the carcass or tusk of any narwhal that is killed. The tags are issued to settlements on a quota basis and are intended to limit the harvest. It is illegal to possess or sell a tusk that is not accompanied by a tag. Because the narwhal is listed on Appendix 11 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, tusks exported from or imported into Canada must be covered by an export or import permit or a re-export certificate. The total narwhal quota has remained at 542 since 1981; Pond Inlet and Arctic Bay are allowed 100 narwhals each, and all other settlements have quotas of 50 or less. |
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SOURCE: Communications Directorate Department of Fisheries and Oceans Ottawa, Ontario K1A 0E6 © Minister of Supply and Services, Canada Cat. No.: Fs 41-33/59-1988E ISBN: 0-662-16501-2 Reprinted 1993 |
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