Coevolution of relative brain size and life expectancy in parrots
Date
2022
Authors
Smeele, Simeon Q.
Conde, Dalia A.
Baudisch, Annette
Bruslund, Simon
Iwaniuk, Andrew N.
Staerk, Johanna
Wright, Timothy
Young, Anna M.
McElreath, Mary Brooke
Aplin, Lucy
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Publisher
Royal Society of London
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.
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Keywords
Psittaciformes, longevity, cognitive evolution, Bayesian structural equation model, cognitivebuffer hypothesis, expensive brain hypothesis
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Source
Proceedings of the Royal Society of London Series B: Biological Sciences
Type
Journal article
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Access Statement
Open Access
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Creative Commons Attribution License
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