Unmistakable all-white color with a distinctive protuberance on the head. They have a dorsal ridge. The body is round and tapers less smoothly to the head than the tail. The tail fin grows and becomes increasingly and ornately curved as the animal ages and the flippers are broad and short.
They are colloquially known as the sea canaries on account of their high-pitched squeaks, squeals, clucks and whistles.
Along the coasts of Alaska, Canada, Greenland, and Russia
Sharks and killer whales
They are resident in well defined areas (Cook Inlet, St. Lawrence estuary, Cumberland Sound), but otherwise strongly migratory: they move offshore in winter to the end of pack ice.
Social system/Group size
Usually seen in groups of up to 15, that are often segregated by age and sex. Occasionally aggregations of several thousand individuals are observed.
The major threats are hunting (mainly by natives), global warming, noise, overfishing and pollution .