Pheomelanin-Based Coloration and the Ability to Cope with Variation in Food Supply and Parasitism

Romain Piault*, Julien Gasparini, Pierre Bize, Susanne Jenni-Eiermann, Alexandre Roulin

*Corresponding author for this work

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

Although gene by environment interactions may play a key role in the maintenance of genetic polymorphisms, little is known about the ecological factors involved in these interactions. We investigated whether food supply and parasites can mediate covariation between the degree of adult pheomelanin-based coloration, a heritable trait, and offspring body mass in the tawny owl (Strix aluco). We swapped clutches between nests to allocate genotypes randomly among environments. Three weeks after hatching, we challenged the immune system of 80 unrelated nestlings with either a phytohemagglutinin (PHA) or a lipopolysaccharide, surrogates of alternative parasites, and then fed them ad lib. or food-restricted them during the following 6 days in the laboratory. Whatever the immune challenge, nestlings fed ad lib. converted food more efficiently into body mass when their biological mother was dark pheomelanic. In contrast, food-restricted nestlings challenged with PHA lost less body mass when their biological mother was pale pheomelanic. Nestling tawny owls born from differently melanic mothers thus show differing reaction norms relative to food availability and parasitism. This suggests that dark and pale pheomelanic owls reflect alternative adaptations to food availability and parasites, factors known to vary in space and time.

Original languageEnglish
Pages (from-to)548-556
Number of pages9
JournalThe American Naturalist
Volume174
Issue number4
Early online date19 Aug 2009
DOIs
Publication statusPublished - Oct 2009

Keywords

  • genotype by environment interaction
  • pheomelanism
  • food availability
  • immune challenge
  • nestlings
  • tawny owl
  • OWL STRIX-ALUCO
  • TAWNY OWLS
  • HETEROGENEOUS ENVIRONMENTS
  • SHORT-TERM
  • POLYMORPHISM
  • EVOLUTION
  • MAINTENANCE
  • TRAIT
  • BIRDS
  • PIGMENTATION

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