Examining the link between relaxed predation and bird coloration on islands.
Biol Lett
; 16(4): 20200002, 2020 04.
Article
em En
| MEDLINE
| ID: mdl-32315593
ABSTRACT
Insular ecosystems share analogous ecological conditions, leading to patterns of convergent evolution that are collectively termed as the 'island syndrome'. In birds, part of this syndrome is a tendency for a duller plumage, possibly as a result of relaxed sexual selection. Despite this global pattern, some insular species display a more colourful plumage than their mainland relatives, but why this occurs has remained unexplained. Here, we examine the hypothesis that these cases of increased plumage coloration on islands could arise through a relaxation of predation pressure. We used comparative analyses to investigate whether average insular richness of raptors of suitable mass influences the plumage colourfulness and brightness across 110 pairs of insular endemic species and their closest mainland relatives. As predicted, we find a likely negative relationship between insular coloration and insular predation while controlling for mainland predation and coloration, suggesting that species were more likely to become more colourful as the number of insular predators decreased. By contrast, plumage brightness was not influenced by predation pressure. Relaxation from predation, together with drift, might thus be a key mechanism of species phenotypic responses to insularity.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ecossistema
/
Evolução Biológica
Limite:
Animals
Idioma:
En
Revista:
Biol Lett
Assunto da revista:
BIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
França
País de publicação:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
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SCOTLAND
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UK
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UNITED KINGDOM