The Autumn Migration of Thick-billed Murres near Southern Baffin Island and Northern Labrador

Abstract

Aerial surveys were used to assess the timing and route of the swimming migration of Thick-billed Murres (Uria lomvia) near southern Baffin Island and northern Labrador in the autumn of 1977, 1978 and 1979. Several hundred thousand adults and chicks from six southern Baffin area colonies departed east through Hudson Strait, in the direction of surface currents, in the latter half of August. Most murres from three eastern Hudson Strait colonies were in offshore waters in early September, arrived in the northern Labrador Sea within a few days, and were followed later in September by murres from three western Hudson Strait colonies. From the Labrador Sea, murres go to marine wintering sites around Newfoundland. Murres from a large colony on southeast Baffin Island apparently did not migrate to the Labrador Sea through western Davis Strait; instead, they either migrated through central Davis Strait en route to Newfoundland, or east to west Greenland, which was also the probable destination of many adult murres which flew by a drillship in southwest Davis Strait.

Key words: Thick-billed Murre (Uria lomvia), migration, Baffin Island, Davis Strait, Labrador Sea, eastern Canada, colonial seabird