チドリ類のオーストラリア到着が年々遅くなっている(Dotterels Reach Australia Later Each Year)

2026-10-12 マックス・プランク研究所

ドイツのマックス・プランク生物知能研究所の研究チームは、ニュージーランドで繁殖し、オーストラリアへ渡るミヤコドリ類の一種、ダブルバンド・ドットレル(Banded Dotterel)の渡りが、年々遅くなっていることを明らかにした。市民科学プラットフォーム「eBird」に2014~2025年に記録された観察データを分析した結果、オーストラリアへの到着時期は平均して毎年約4日遅くなり、非繁殖期の滞在期間は2014年の推定173日から2025年には129日へと約25%短縮した。一方、ニュージーランドへの帰還時期には明確な変化が認められなかった。研究チームは、この変化を人為的な地球温暖化に伴う南半球の偏西風の変化と関連付け、ニュージーランドの秋冬が穏やかになったことが渡りの時期に影響していると考えている。この傾向が続けば、数十年以内にオーストラリアへの渡り行動そのものが失われる可能性がある。成果は、気候変動が動物の季節移動や生態、保全に及ぼす影響の理解に貢献する。

チドリ類のオーストラリア到着が年々遅くなっている(Dotterels Reach Australia Later Each Year)

Using sightings by citizens logged on the platform eBird, the researchers showed that New Zealand banded dotterels arrive to overwinter in Australia from New Zealand about four days later each year between 2014 and 2025.  © MPI for Biological Intelligence / Bashar Jarayseh

<関連情報>

南半球の渉禽類の渡りスケジュールの急激な変化は、南半球の気候変動と関連している A rapid shift in migration schedule of an Austral shorebird is linked to a changing southern climate oscillation

Bashar Jarayseh, Luke Eberhart-Hertel, Bart Kempenaers

International Journal of avian Science  Published: 28 September 2026

DOI:https://doi.org/10.1111/ibi.70128

Abstract

Global climate change is reshaping the schedules and routes of migratory birds, which can disrupt annual cycles, ecological interactions and the fitness trade-offs of migrating or staying resident. In particular, climate change has led to advances in arrival at the breeding grounds and to shifts in the timing of post-breeding migration, whereby both later and earlier departures have been reported. Here, we studied the migration phenology of the Banded Dotterel Anarhynchus bicinctus, a small shorebird breeding exclusively in New Zealand but exhibiting highly variable seasonal movements that range from year-round residency to trans-oceanic longitudinal migration to (mainly) Australia. We used 12 years of citizen science data to estimate population-level arrival and departure dates of migrants at their Australian non-breeding grounds. We assessed temporal and spatial variation in migration phenology and explored potential links to climate change. Since 2014, Banded Dotterel post-breeding arrival to Australia has been delayed by an estimated 4 days annually but prebreeding departure dates back to New Zealand showed no change – collectively reducing the species’ non-breeding residency duration in Australia by 25% (44 days) over the study period. The timing of arrival in Australia was positively associated with the Southern Annular Mode at the end of the New Zealand breeding season, suggesting that the southern contraction of the westerly wind belt circling Antarctica is postponing the species’ (preparation for) post-breeding migration. These findings suggest a rapid change in migration behaviour in response to climate change in a Southern Hemisphere species with a unique east–west migratory route.

1903自然環境保全
ad
ad
Follow
ad
タイトルとURLをコピーしました