大きな脳を持つオウムの中には、驚くほど長生きする種がいることが、新たな研究で明らかになった Bigger brains have led some species of parrot to live surprisingly long lives, new research shows
2022-03-29 マックス・プランク研究所
・217種のオウムを調査した結果、コガネメキシコインコやスズメガのような種は、平均寿命が30年と非常に長く、通常は大型の鳥類にしか見られないことが明らかになったのです。
・これらの長寿の原因として、脳の大きさが相対的に大きいことが考えられることを実証した。この研究は、オウムの脳の大きさと寿命の関係を示した初めての例であり、認知能力の向上が、環境中の脅威を回避し、長寿を享受するのに役立った可能性を示唆している。
<関連情報>
- https://www.mpg.de/18488364/0329-ornr-unravelling-the-mystery-of-parrot-longevity-987453-x?c=2249
- https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2397
オウムの相対的な脳の大きさと寿命の共進化 Coevolution of relative brain size and life expectancy in parrots
Simeon Q. Smeele,Dalia A. Conde,Annette Baudisch,Simon Bruslund,Andrew Iwaniuk,Johanna Staerk,Timothy F. Wright,Anna M. Young,Mary Brooke McElreath,and Lucy Aplin
Published:23 March 2022 https://doi.org/10.1098/rspb.2021.2397
Abstract
Previous studies have demonstrated a correlation between longevity and brain size in a variety of taxa. Little research has been devoted to understanding this link in parrots; yet parrots are well-known for both their exceptionally long lives and cognitive complexity. We employed a large-scale comparative analysis that investigated the influence of brain size and life-history variables on longevity in parrots. Specifically, we addressed two hypotheses for evolutionary drivers of longevity: the cognitivebuffer hypothesis, which proposes that increased cognitive abilities enable longer lifespans, and the expensive brain hypothesis, which holds that increases in lifespan are caused by prolonged developmental time of, and increased parental investment in, large-brained offspring. We estimated life expectancy from detailed zoo records for 133 818 individuals across 244 parrot species. Using a principled Bayesian approach that addresses data uncertainty and imputation of missing values, we found a consistent correlation between relative brain size and life expectancy in parrots. This correlation was best explained by a direct effect of relative brain size. Notably, we found no effects of developmental time, clutch size or age at first reproduction. Our results suggest that selection for enhanced cognitive abilities in parrots has in turn promoted longer lifespans.
