Avifauna of Kita-iwoto Island, the Volcano Island Group, in 2019
| Autor: | KAWAKAMI, Kazuto, SUZUKI, Hajime, HORIKOSHI, Sora |
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| Jazyk: | japonština |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | 小笠原研究 = Ogasawara research. 47:185-200 |
| ISSN: | 0386-8176 |
| Popis: | 北硫黄島で2018年10月、2019年6月に鳥類相調査を行った。その結果、繁殖またはその可能性が高い種として3種の海鳥(アカオネッタイチョウ、アカアシカツオドリ、カツオドリ)および5種の陸鳥(カラスバト、ヒヨドリ、メジロ、トラツグミ、イソヒヨドリ)が確認された。アカアシカツオドリでは153巣を含む集団繁殖地がこの島で初めて見つかり、国内で2ヶ所目の記録となった。過去約10～20年の間に、カツオドリおよびヒヨドリの個体数は大きな変化はなかったが、メジロでは有意に減少していた。この島では外来ネズミの捕食で多数の鳥種が局所絶滅したと考えられる。火山列島の生物相の持つ価値の維持のため、ネズミ類を根絶することが望ましい。 A field survey was conducted to clarify the current status of avifauna on Kita-iwoto, the Volcano Island Group, in June 2019. A preliminary survey was conducted in October 2018 using an unmanned aerial vehicle. The breeding, or high possibility of breeding, was observed for the following species: three seabird species (Red-tailed Tropicbird Phaethon rubricauda, Red-footed Booby Sula sula and Brown Booby Sula leucogaster) and five land bird species (Japanese Wood-Pigeon Columba janthina, Brown-eared Bulbul Hypsipetes amaurotis, Japanese White-eye Zosterops japonicus, Scaly Thrush Zoothera dauma and Blue Rock-Thrush Monticola solitarius). Discovery of a breeding colony of the Red-footed Booby was recorded for the first time on this island; this was only the second recording of a breeding colony in Japan. The populations of Brown Booby and Brown-eared Bulbul were estimated to have been stable over the past decade, while the Japanese White-eye has significantly declined in number during that time period. Nine bird species that bred before World War II have not been confirmed as breeding in this location since that time; the main cause for this change is likely predation by introduced rats. The Volcano Islands have a very unique biota and the birds perform important ecosystem functions; to maintain and promote the restoration of the unique avian fauna, rats need to be eradicated. |
| Databáze: | OpenAIRE |
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