Melanin-based colorations signal strategies to cope with poor and rich environments

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Etat: Public
Version: de l'auteur
ID Serval
serval:BIB_CDF4E162CA18
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Melanin-based colorations signal strategies to cope with poor and rich environments
Périodique
Behavioral Ecology and Sociobiology
Auteur(s)
Roulin A., Gasparini J., Bize P., Ritschard M., Richner H.
ISSN
0340-5443
Statut éditorial
Publié
Date de publication
2008
Peer-reviewed
Oui
Volume
62
Numéro
4
Pages
507-519
Langue
anglais
Résumé
One hypothesis for the maintenance of genetic variation states that alternative genotypes are adapted to different environmental conditions (i.e., genotype-by-environment interaction GxE) that vary in space and time. Although GxE has been demonstrated for morphological traits, little evidence has been given whether these GxE are associated with traits used as signal in mate choice. In three wild bird species, we investigated whether the degree of melanin-based coloration, a heritable trait, covaries with nestling growth rate in rich and poor environments. Variation in the degree of reddish-brown phaeomelanism is pronounced in the barn owl (Tyto alba) and tawny owl (Strix aluco), and variation in black eumelanism in the barn owl and Alpine swift (Apus melba). Melanin-based coloration has been shown to be a criterion in mate choice in the barn owl. We cross-fostered hatchlings to test whether nestlings sired by parents displaying melanin-based colorations to different extent exhibit alternative growth trajectories when raised by foster parents in poor (experimentally enlarged broods) and rich (experimentally reduced broods) environments. With respect to phaeomelanism, barn owl and tawny owl offspring sired by redder parents grew more rapidly in body mass only in experimentally reduced broods. With respect to eumelanism, Alpine swift offspring of darker fathers grew their wings more rapidly only in experimentally enlarged broods, a difference that was not detected in reduced broods. These interactions between parental melanism and offspring growth rate indicate that individuals display substantial plasticity in response to the rearing environment which is associated with the degree of melanism: at least with respect to nestling growth, phaeomelanic and eumelanic individuals are best adapted to rich and poor environments, respectively. It now remains to be investigated why eumelanism and phaeomelanism have a different signaling function and what the lifelong consequences of these melanism-dependent allocation strategies are. This is important to fully appraise the role played by environmental heterogeneity in maintaining variation in the degree of melanin-based coloration.
Mots-clé
genetic variation, genotype-by-environment interaction, growth, melanin-based coloration, phenotypic plasticity, strategy, stress
Web of science
Création de la notice
01/09/2008 22:46
Dernière modification de la notice
20/08/2019 15:48
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