A new study has suggested that the social environment of mother quails has a direct influence on the growth and the behaviour of their young.
The recent study has been performed by Floriane Guibert and Cecilia Houdelier at the CNRS-Universite de Rennes 1 in France, together with researchers at the INRA in Nouzilly, France and with Austrian scientists including Erich Mostl of the University of Veterinary Medicine, Vienna.
It may sound surprising that quails are able to distinguish one another, let alone that they form close relationships with other quails.
Nevertheless, it has long been known that disruption of the birds' social environment causes them stress.
The team of researchers has shown that changing the composition of groups of quails housed together causes the birds to behave more aggressively towards one another. In parallel, the level of steroid hormones (corticosterone) in their blood increases when their group composition is disrupted.
Intriguingly, the eggs they lay were found to have significantly higher levels of testosterone when the mothers were subjected to social stress of this kind.
The results are consistent with previous findings from other groups, which showed that House sparrows, American coots and Common starlings lay eggs with more testosterone when they breed in dense colonies than when they nest in isolation.
But the new work has also shown that the eggs of females under social stress hatch later and the chicks grow more slowly after hatching, at least for the first three weeks.