Seabird migration in the Canadian northwest Atlantic Ocean: moulting locations and movement patterns of immature birds

Abstract

All seabirds in the northwest Atlantic Ocean migrate, but timing and routes are not well understood. We evaluate existing knowledge on seabird migration with data from the Programme intégré de recherches sur les oiseaux pélagiques (PIROP) data base, using observations of immature and moulting seabirds to track migration of the following species: Northern Fulmar (Fulmarus glacialis), Greater Shearwater (Puffinus gravis), Northern Gannet (Morus bassanus), Herring Gull (Larus argentatus), Iceland Gull (Larus glaucoides), Glaucous Gull (Larus hyperboreus), Great Black-backed Gull (Larus marinus), Black-legged Kittiwake (Rissa tridactyla), and Thick-billed Murre (Uria lomvia). The distributions of immature and moulting birds show strong seasonal patterns in the northwest Atlantic, and new transition zones and clear biological borderlines for seabird distribution were found. New data on timing and location of moulting Thick-billed Murres are presented. The southern Labrador Banks and Grand Banks (Thick-billed Murre, Northern Fulmar) and southeast Newfoundland and Georges Bank (Greater Shearwater) were identified as moulting grounds. In terms of marine conservation the following areas seem to be important for part of the life cycle of the species named: western Greenland, Cape Cod, Grand Banks, Labrador Banks, southwest Newfoundland, and the Grand Manan area.