A mass inland drift of Streaked Shearwaters over Kanto plain in November, 1965

Abstract

1. From November 19th, especially 21-24th, there was a mass inland drift of Calonectris leucomelas over the whole Kanto plain covering nine prefectures.
2. The numbers reported were: Fukushima 9, Ibaragi 166, Tochigi 10, Gumma 1, Saitama 20, Chiba 87, Tokyo 102, Kanagawa 3 and Shizuoka 2, in total 400 birds.
3. They were found alive but weakened and 323 were collected at Ueno Zoo, Tokyo and after being fed most of them were transported to Kagoshima where they were released with leg band. Others were released elsewhere and some died.
4. A disturbed weather with strong winds and heavy fogs during 19-21 November could be correlated with this accidental event.
5. Although such a weather change is not unusual in this season when winter weather becomes prevailed and occasional stragglers are drifted inland as known in Kyoto (Yoshida, 1962) and Japan Sea coast, 1965-event would have been due to an accidental coincidence of a juvenile-bird flock just left the breeding island, Sanganjima, with a sudden weather change.
6. From measurements of 226 wing lengths and 223 culmens and examination of some examples, they were mostly (perhaps at least 75%) young of the year judging from the comparison of measurements of adult breeding birds of Sanganjima. Adult flocks would have gone ahead or had stronger weather resistance and better orientation ability.