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.

Makes long transequatorial migrations between breeding and nonbreeding ranges, though some birds may spend the nonbreeding period south of the equator. Migrates along Atlantic coast of U.S. May-June; to Canada Labrador, and southern Greenland July-late September. Moves eastward out to sea in late northern summer. Millions of migrants occur off U.S. Pacific coast in northern spring and summer (Briggs and Chu 1986). Sporatically common to abundant off Pacific coast of Costa Rica mainly May-October (Stiles and Skutch 1989).