Birds which follow the shoal of Bonitoes in waters south of Japan

Abstract

Birds which follow the shoal of Bonitoes Katsuwonus pelamis were counted on the fishing-grounds in 1960-61. As an indicator of the shoal of Bonitoes, 5 species (Wedgetailed Shearwater Puffinus pacificus, Sooty Tern Sterna fuscata, Noddy Anous stolidus, Red-legged Gannet Sula sula and Brown Gannet Sula leucogaster) were important in the sea near Mariana Is., 2 species (Streaked Shearwater Calonectris leucomelas and Sooty Tern) were important south of Izu Is. (between 31°N and 32°N) and 2 species (Wedgetailed Shearwater and Streaked Shearwater) were important on the "Higashi-Oki" (145°E, 35°N). But on the sea near Sofugan, there was no bird which follows the shoal of Bonitoes.