Experience in the egg influences precocial birds later ability to cope with their environment
Résumé
In birds, the qualities of eggs as well as the sensory stimulation surrounding the embryos can influence the ontogeny of behaviour. In quail, we found that the quality of the human-animal relationship and the housing conditions of mothers influenced the quantity of yolk androgens available for embryos. In turn, emotional reactivity, social motivation and courtship behaviour of offspring were affected. Divergent selection based on emotional or social traits also lead to divergent levels of yolk hormones. These traits thus appear to be determined, at least in part, by the prehatch endocrine environment, itself resulting from the experience and genotype of mothers. Prehatch exposure to testosterone facilitated auditory learning of a maternal call, indicating that the endocrine environment can also modify prenatal perceptual development. Finally, we found that that the prenatal experience of domestic chicken embryos with olfactory stimuli guides their later feeding behaviour. Taken together, these findings indicate that the experience of embryos in the egg guides their later post-hatching ability to cope with their environment.