Behavioral study related to reproductive isolation in the endangered Shor-tailed albatross, consists of two species

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05641
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39060:Conservation of biological resources-related
• Research Institution: Yamashina Institute for Ornithology
• Principal Investigator: Tomita Naoki 公益財団法人山階鳥類研究所, その他部局等, 研究員 (90619917)
• Co-Investigator(Kenkyū-buntansha): 江田 真毅 北海道大学, 総合博物館, 教授 (60452546) ; 出口 智広 兵庫県立大学, 地域資源マネジメント研究科, 准教授 (60414091)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: アホウドリ / 鳥島 / 尖閣諸島 / 保全単位 / 非繁殖期 / 繁殖タイミング

Outline of Final Research Achievements

Using the situation where two types of Short-tailed albatrosses (Torishima type and Senkaku type), which were found to be cryptic species, breed sympatrically on Torishima, we aim to directly examine the ecological factors related to pre-mating isolation, such as differences in the areas used by the two types during the non-breeding season, as well as the timing of breeding initiation and migration, at the individual level and reexamine the conservation unit. These studies revealed that the waters used by the Torishima and Senkaku types during the non-breeding season tend to be different. Genetic analysis also revealed that hybridization between the two types has been observed in the past on Torishima Island, but at a low frequency, suggesting that reproductive isolation has been historically enhanced.

Free Research Field

鳥類生態学，保全生物学

Academic Significance and Societal Importance of the Research Achievements

海鳥では，同じ繁殖集団でも非繁殖地が異なる例が多く，複数の保全単位からなる可能性が高い．アホウドリは一つの保全単位として，絶滅確率などが計算され，それに基づき保全戦略がたてられている．遺伝的特性から二つの保全単位からなる可能性があるが，本研究は生態的特性から二つの単位として扱うべきか検討した．非繁殖地ごとに汚染や混獲などのリスクが大きく異なる場合，同じ繁殖地の集団でも保全単位ごとにこれらのリスクに応じた対策をとる必要が出てくる．これは，保全を必要とする渡り性の鳥類すべてにあてはまる問題であり，応用範囲は広い．