Feeding ecology and body size dependence on diet of the Sooty Shearwater, Puffinus griseus, in the North Pacific

• Main Authors: Shiomi,Kouzi, Ogi,Haruo
• Format: Report
• Language: English
• Published: Research Institute of North Pasific Fisheries,Faculty of Fisheries, Hokkaido University/Research Institute of North Pasific Fisheries, Faculty of Fisheries, Hokkaido University 1992
• Subjects: Pacific; Polar Biology; Proceedings of the NIPR Symposium on Polar Biology; Subarctic
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=5158; http://id.nii.ac.jp/1291/00005158/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=5158&item_no=1&attribute_id=18&file_no=1

The diet of the Sooty Shearwater (Puffinus gnseus) was examined by using a total of 1139 stomachs of the bird sampled during April-October, 1982, 1985-1989. Of all stomachs, 586 were empty. Predominant prey species was the Japanese sardine (Sardmops melanostictd), the wet weight percentage of which was 57.9% in the Confluence Zone, April-May, and 55.8% in the Subarctic Current, June-September. Other identified prey species were the Pacific saury (Cololabis saira), squid (Berryteuthis anonychus), pelagic barnacle (Lepas fasciculans), and jellyfish (Vellela laid). In the Subtropical Zone, June-July and the Transition Domain, June-October, the relative importance of squid and pelagic barnacle as prey items for the bird increased in both frequency of occurrence and weight. The importance of fish in the diet increased with body weight increment of the bird, while that of squid and barnacle decreased. This trend was remarkably observed in the Subtropical Zone and the Transition Domain. It is, therefore, suggested that the diet of the bird changes with their growth.