Post-breeding movement and activities of two streaked shearwaters in the north-western Pacific

We used miniature light-level/immersion loggers (geolocators) to study the movements and behavior of two Streaked Shearwaters (Calonectris leucomelas) during their travel away from Japan, after the breeding season. During the period from late October until late December, the tracked shearwaters moved south over subtropical pelagic waters,with low productivity. The birds traveled to the seas off northern New Guinea and the Gulf of Carpentaria, Australia, 3400-5200 km distant from Mikura Island, their breeding colony in Japan. During the wintering period (December-February), the birds were on the sea surface for 77-85% of their time on average. The migratory and wintering behavior of Streaked Shearwaters are discussed in relation to the physical and biological marine environment of the north-western Pacific.