Foster parent experiment reveals no genotype-environment correlation in the external morphology of Ficedula albicollis, the collared flycatcher

Abstract

Heritabilities of quantitative traits have recently been estimated in several natural populations of birds. The predictive value of these estimates is based on the assumption that heritability estimates are not inflated by an environmental correlation between parent and offspring. We here show with a foster experiment that heritability estimates of seven morphological traits in the collared flycatcher are not inflated as a result of a genotype-environment correlation. Surprisingly, there was a negative foster parent-offspring relation in a poor environment. It is suggested that large foster parents have more difficulties raising offspring under poor environmental conditions than do small foster parents. Our experiment also provides evidence for a heritable basis of phenotypic variation in feather traits and that the morphology of the collared flycatcher could respond rapidly to selection.