研究ノート
青森県八戸市大久喜の弁天島におけるウミネコの繁殖状況
2022 年 54 巻 2 号 p. 280-285
詳細
2022 年 54 巻 2 号 p. 280-285
A total of 1,179 nests (55 with no eggs) of Black-tailed Gulls Larus crassirostris were observed at three sites on Bentenjima Island, Okuki, Hachinohe City, on May 15, 2021, and 489 chicks were counted on June 26. Apparent clutch size (excluding nests with no eggs) and fledging success were 1.9 and 21.7%, respectively. Fledging success was lowest on the rock connected to the mainland by a breakwater, presumably because of disturbance by terrestrial animals. A total of 16 individuals with metal leg bands were observed and were 2–22 years old. These were immigrants from Kabushima Island, 10 km northwest of Okuki. Bentenjima Island is an important breeding site of the Black-tailed Gulls in northern Japan, and needs to be monitored.
