海洋諸島における鳥類の絶滅と哺乳類の導入
Tim M Blackburn1, Phillip Cassey, Richard P Duncan
1School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. t.blackburn@bham.ac.uk
まとめ
人間によって導入されたエキゾチックな捕食性哺乳類は,多くの島鳥の絶滅の原因となっている. この影響は,島原生種に対してより大きく,島の鳥類に対する主要な脅威における歴史的なシフトを示唆しています.
科学分野:
- エコロジー エコロジー エコロジー
- 保護生物学の保護生物学
- 鳥類学 鳥類学とは,鳥類学である.
背景:
- 海洋諸島の人類による植民地化は,鳥類の大規模な絶滅につながった.
- 絶滅の深刻さは,様々な島の鳥の集団によって異なる.
研究 の 目的:
- 導入された捕食性哺乳類と海洋の島々での鳥類の絶滅の間の相関を調査する.
- 捕食者の影響が固有の島鳥種と固有の島鳥種でない島鳥種に差があるかどうかを判断する.
主な方法:
- 220の海洋島の鳥類の絶滅確率の統計分析.
- 確立されたエキゾチック哺乳類の捕食動物種の数と絶滅の出来事の間の関係を評価する.
- 島に生息する固有種と非固有種の捕食者の影響を比較する.
主要な成果:
- エキゾチックな捕食性哺乳類の種数と鳥類の絶滅の確率は正の相関関係にある.
- エキゾチックな肉食動物は,島に固有の鳥類に,より大きな影響を及ぼします.
- 現在,絶滅の危機に瀕している鳥類の割合は,異国的な捕食動物である哺乳類の数に依存していない.
結論:
- 導入された捕食性哺乳類は,海洋の島々での歴史的な鳥類の絶滅の主要な原動力である.
- 島鳥に対する主な脅威は,時間とともに進化し,捕食は感受性の高い種にとって主要な要因となっています.
- 保護戦略は,侵襲的な捕食動物が島の生物多様性に及ぼす歴史的な影響を考慮する必要があります.
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