Not highly migratory. With exception of resident populations in California, species disperses mainly from breeding grounds toward adjacent deeper oceanic waters.
Timing And Routes Of Migration
At most northerly colonies (e.g. East Amatuli Island Alaska), arrives in May but because of snow at high elevations, access to nesting sites may be delayed until late May or June. At Tatoosh I., Washington, more individuals caught in February and March than later; these early birds are also significantly heavier, suggesting individuals may be prospecting at breeding colonies in early spring while migrating north. Individuals from southern colonies (California) may frequent the colony throughout the year.
Not known where breeders from different parts of range winter or how distribution and use of marine habitat differs by sex, age, or breeding status.
Little known. Birds usually alone or in small, loosely aggregated flocks..