2026-01-20 オックスフォード大学
オックスフォード大学とオックスフォード・ブルックス大学が主導する10年間にわたる大規模な研究で、南極のペンギン3種が繁殖シーズンを約2週間前倒ししていることが明らかになった。この現象は気候変動に伴う環境の急激な変化、とくにコロニー周辺の気温上昇が世界平均の4倍近い速度で進んでいることと関連しているとみられる。研究では、アデリーペンギン、ヒゲペンギン、ジェンツーペンギンの37コロニーで77台のタイムラプスカメラを用い、2012〜2022年の「定着」開始時期を分析した。ジェンツーは1デシオンあたり平均13日(最大24日)前倒し、他の2種も平均10日という鳥類史上、あるいは脊椎動物史上最速級の繁殖シフトを示した。一般的な採食者であるジェンツーはこの変化に適応しつつあるが、氷やオキアミに依存するアデリーとヒゲは繁殖時期の重複や餌不足で競争が激化し、個体数減少のリスクが高まっている。研究は『Journal of Animal Ecology』に掲載され、気候変動の生態系への影響がペンギンにも及んでいることを示す警鐘となる。
<関連情報>
- https://www.ox.ac.uk/news/2026-01-20-two-week-leap-breeding-study-reveals-antarctic-penguins-striking-climate-adaptation
- https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2656.70201
同所性ペンギン3種における気候変動に対する記録的な季節的反応 Record phenological responses to climate change in three sympatric penguin species
Ignacio Juarez Martinez, Alex Kacelnik, Fiona M. Jones, Jefferson T. Hinke, Michael J. Dunn, Andrea Raya Rey, Heather J. Lynch, Kate Owen, Tom Hart
Journal of Animal Ecology Published: 19 January 2026
DOI:https://doi.org/10.1111/1365-2656.70201
Abstract
- The timing of breeding is an important aspect of any species’ realised niche, reflecting adaptations to synchronise with food supplies, dilute predation, avoid competition and exploit seasonal fluctuations in resources. Breeding phenology is typically studied either through long-term monitoring of focal populations (limiting the strength of inferences about species-wide traits and trends) or, when conducted at a landscape level, using remotely visible traits (restricting most studies to plants).
- For the first time, this study demonstrates landscape-scale measurement of vertebrate breeding phenology using a network of 77 time-lapse cameras to monitor three sympatric penguin species across 37 colonies in the Antarctic Peninsula and Sub-Antarctic islands.
- Camera temperature loggers showed penguin colony locations are warming up four times faster (0.3°C/year) than the continental average (0.07°C/year), already the second fastest-warming area in the world.
- We analysed the start of the breeding season of Adélie, Chinstrap and Gentoo penguins at a sub-continental scale between 2012 and 2022. The phenology of all three species advanced at record rates (10.2 ± 2, 10.4 ± 1.5 and 13 ± 4 days/decade, respectively).
- Different demographic trends as well as intra- and inter-species differences in response to environmental change suggest niche-based response differences between species.
- Phenological advances are causing niche separation to reduce. In this context, the Gentoo penguins’ generalist and resident nature seems better suited to compete for space and resources than krill-specialist Chinstraps and ice-specialist Adélies.
- Synthesis: A decade of observation of the three pygoscelid penguins shows they are advancing their settlement phenology at record speeds in relation to climate change across the Antarctic Peninsula. These changes are species-dependent, reflecting different vulnerabilities and opportunities depending on their niche and life-history traits. In the long term, the trend towards earlier settlement risks increasing inter-species competition, causing trophic and temporal mismatch, and reshaping community assemblages.
