Beluga and Narwhal: Monodontidae

Both narwhals and beluga whales live in small groups or pods, although these pods may gather in groups of hundreds or thousands of animals during migrations. These species are social and communicate with a wide range of sounds. Both species migrate. The narwhal follows the ice pack, moving north as it melts in summer and south as it grows in winter. The migration of belugas appears to be triggered by day length. Not all groups of belugas migrate. One well-studied group that live at the mouth of the St. Lawrence River in Canada appears to stay there year round.

These whales give birth to a single calf at a time after a pregnancy lasting thirteen to sixteen months. The calf nurses, feeds on breast milk, and remains dependent on its mother for up to two years. Mating usually occurs in late winter or early spring and births occur in the summer of the following year.