Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Movements associated with distribution and movement of sea ice. In some areas makes extensive north-south migrations (DeMaster and Stirling 1981) that are dependent on seasonal melting and freezing of nearshore ice (Amstrup 2003). Moves south with drifting ice flows in spring/summer, north along shore in summer after ice breakup. See Amstrup (1995) for extensive information on movements in the Chukchi and Beaufort Seas.