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).