Smaller brained cliff swallows are more likely to die during harsh weather.

Biology Letters
Gigi S Wagnon, C R Brown

Abstract

The cognitive-buffer hypothesis proposes that more harsh and unpredictable environments favour animals with larger brains and resulting greater cognitive skills. Comparisons across taxa have supported the hypothesis, but it has rarely been tested within a species. We measured brain size, as inferred from head dimensions, for 1141 cliff swallow specimens collected in western Nebraska, 1982-2018. Cliff swallows starving to death during unusual late-spring cold snaps had significantly smaller brains than those dying from other causes, suggesting that brain size in this species can affect foraging success and that greater cognitive ability may confer advantages when conditions exceed normal environmental extremes. Brain size declined significantly with the size of the breeding colony from which a specimen came. Larger brains may be favoured in smaller colonies that represent more unpredictable and more challenging social environments where there is less public information on food sources and less collective vigilance against predators, even in relatively normal conditions. Our results provide intraspecific support for the cognitive-buffer hypothesis and emphasize the potential evolutionary impact of rare climatic events.

References

Jan 1, 1993·Proceedings of the National Academy of Sciences of the United States of America·J AllmanA Hakeem
Dec 20, 2000·Proceedings of the National Academy of Sciences of the United States of America·C R Brown, M B Brown
Apr 27, 2002·Science·Peter R Grant, B Rosemary Grant
Mar 24, 2005·Proceedings of the National Academy of Sciences of the United States of America·Daniel SolLouis Lefebvre
Jul 14, 2005·Proceedings. Biological Sciences·Daniel SolJ Domingo Rodríguez-Teijeiro
Jul 18, 2006·Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences·John F B MitchellMichael Vellinga
Dec 7, 2006·Biology Letters·Susanne Shultz, R I M Dunbar
Jan 26, 2007·Proceedings. Biological Sciences·Daniel SolLouis Lefebvre
Mar 7, 2008·Brain, Behavior and Evolution·Cynthia Schuck-PaimEduardo B Ottoni
May 22, 2010·Journal of Evolutionary Biology·A P Møller
Jun 4, 2010·Proceedings. Biological Sciences·Timothy C RothVladimir V Pravosudov
Sep 18, 2010·BMC Medical Research Methodology·David VergouwDaniëlle A W M van der Windt
Mar 23, 2013·Current Biology : CB·Charles R Brown, Mary Bomberger Brown
May 12, 2015·Ecology Letters·Alexander KotrschalNiclas Kolm
Jul 21, 2016·Evolution; International Journal of Organic Evolution·Orsolya Vincze
Dec 23, 2016·Nature Communications·Ferran SayolDaniel Sol
Apr 14, 2017·Royal Society Open Science·Anders Pape Møller, Johannes Erritzøe
Oct 1, 1998·Evolution; International Journal of Organic Evolution·Charles R Brown, Mary Bomberger Brown

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