Insularity and the evolution of melanism, sexual dichromatism and body size in the worldwide-distributed barn owl.

Détails

Ressource 1Télécharger: BIB_C4B15CC3C0A4.P001.pdf (158.28 [Ko])
Etat: Serval
Version: Final published version
ID Serval
serval:BIB_C4B15CC3C0A4
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Insularity and the evolution of melanism, sexual dichromatism and body size in the worldwide-distributed barn owl.
Périodique
Journal of Evolutionary Biology
Auteur(s)
Roulin A., Salamin N.
ISSN
1420-9101[electronic], 1010-061X[linking]
Statut éditorial
Publié
Date de publication
2010
Peer-reviewed
Oui
Volume
23
Numéro
5
Pages
925-934
Langue
anglais
Notes
Publication types: JOURNAL ARTICLE
Résumé
Abstract Island biogeography has provided fundamental hypotheses in population genetics, ecology and evolutionary biology. Insular populations usually face different feeding conditions, predation pressure, intraspecific and interspecific competition than continental populations. This so-called island syndrome can promote the evolution of specific phenotypes like a small (or large) body size and a light (or dark) colouration as well as influence the evolution of sexual dimorphism. To examine whether insularity leads to phenotypic differentiation in a consistent way in a worldwide-distributed nonmigratory species, we compared body size, body shape and colouration between insular and continental barn owl (Tyto alba) populations by controlling indirectly for phylogeny. This species is suitable because it varies in pheomelanin-based colouration from reddish-brown to white, and it displays eumelanic black spots for which the number and size vary between individuals, populations and species. Females are on average darker pheomelanic and display more and larger eumelanic spots than males. Our results show that on islands barn owls exhibited smaller and fewer eumelanic spots and lighter pheomelanic colouration, and shorter wings than on continents. Sexual dimorphism in pheomelanin-based colouration was less pronounced on islands than continents (i.e. on islands males tended to be as pheomelanic as females), and on small islands owls were redder pheomelanic and smaller in size than owls living on larger islands. Sexual dimorphism in the size of eumelanic spots was more pronounced (i.e. females displayed much larger spots than males) in barn owls living on islands located further away from a continent. Our study indicates that insular conditions drive the evolution towards a lower degree of eumelanism, smaller body size and affects the evolution of sexual dichromatism in melanin-based colour traits. The effect of insularity was more pronounced on body size and shape than on melanic traits.
Mots-clé
body size, continent, indirect selection, island, melanin-based colouration, natural and sexual selection, sexual dimorphism
Pubmed
Web of science
Open Access
Oui
Création de la notice
20/04/2010 14:45
Dernière modification de la notice
09/05/2019 0:57
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