Steaked shearwaters observed on the seas south of Japan, with notes on other species

Abstract

This report is based on the observations in the sea region south of Japan (Fig. 1-1; 2-1) from "Seiyo-maru" (the training and research ship belonging to the Tokyo University of Fisheries) in the midsummer (July to August) of 1967 and the spring (March to April) of 1968. As a result, the followings are summarized: a) Flying Streaked shearwaters were generally observed within the range of about 100 nautical miles from land, and offshore it decreased in number.
Exceptionally, it was remarkable that over 40 Streaked shearwaters were observed at about lat. 31°N, long. 139°E, just where the long-line fishing was being operated.
b) The floating Streaked shearwaters were very often observed along the current-rips.
c) The observations from the Seiyo-maru's cruises suggest that the Streaked shearwater has a southern limit of its distribution range in lat. 30°N. in the northwest Pacific Ocean.
d) Other tropical and subtropical species such as Wedge-tailed shearwater, Pink-footed shearwater, Bulwer's petrel, Brown noddy and Nordmann's tern were also observed in these regions.