Monodon monoceros
TAXONOMY
Monodon monoceros Linnaeus, 1758, northern seas of Europe and America.
OTHER COMMON NAMES
French: Narval; German: Narwal; Spanish: Narval.
PHYSICAL CHARACTERISTICS
Length 14–15.5 ft (4.2–4.7 m); weight 2,200–3,500 lb (1,000–1,600 kg).
DISTRIBUTION
Disjunct Arctic circumpolar; main concentrations in Greenland Sea, Davis Strait/Baffin Bay, Hudson Strait, northern Hudson Bay, and their adjacent sounds and inlets.
HABITAT
Deep marine waters, including inshore fjords and sounds in summer and offshore heavy pack-ice zone in winter.
BEHAVIOR
Roll at surface showing back but generally not head or flukes; same-sex pods (e.g., groups containing only males with large tusks); strongly migratory, moving in large groups of associated pods, totaling hundreds of animals. Reports of males crossing their tusks above the surface ("fencing") are difficult to interpret. Scars on head region and high incidence of broken tusk tips imply aggressive tusk use, perhaps in dominance interactions.
FEEDING ECOLOGY AND DIET
Deep divers that feed on shrimp, squid, schooling pelagic fish, and deepwater species such as halibut and redfish.
REPRODUCTIVE BIOLOGY
Single calf born in summer after gestation period of 13 to 16 months; lactation one to two years; inter-birth interval three years, on average. Mating system is unknown.
CONSERVATION STATUS
Present and historical abundance uncertain, but recent estimates for main areas of distribution in Canada and Greenland total close to 40,000, without adjusting for negative bias. Continued hunting, with no quotas, growing human populations in hunting districts, and no expected reduction in demand for products, signals the need for closer monitoring and management to prevent further depletion.
SIGNIFICANCE TO HUMANS
"Unicorn" tusks of adult males give species a special place in history and mythology. While intact, tusks continue to have high commercial value as curiosities in international trade, and the ivory is also used for carving, especially in Greenland. Skin a much-valued human food among Inuit.
