Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
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.
Migratory in some regions, nonmigratory in other regions. Migrations apparently are related to movements of prey species.
The longest known movement involved three individuals photographed in Glacier Bay, Alaska, on 6 August 1989, and subsequently observed attacking gray whales in Monterey Bay, California, on 2 May 1992 (Goley and Straley 1994); whether this movement was transitory or migratory is unknown.