The influence of maternal glucocorticoids on offspring phenotype in high- and low-risk environments

Elevated maternal glucocorticoid levels during gestation can lead to
phenotypic changes in offspring via maternal effects. Although such
effects have traditionally been considered maladaptive, maternally derived
glucocorticoids may adaptively prepare offspring for their future
environment depending upon the correlation between maternal and offspring
environments. Nevertheless, relatively few studies test the effects of
prenatal glucocorticoid exposure across multiple environments. We
tested the potential for ecologically relevant increases in maternal
glucocorticoids in the eastern fence lizard (Sceloporus undulatus) to
induce adaptive phenotypic changes in offspring exposed to high or low
densities of an invasive fire ant predator. Maternal treatment had limited
effects on offspring morphology and behaviour at hatching, but by 10 days
of age, we found maternal treatment interacted with offspring environment
to alter anti-predator behaviours. We did not detect differences in
early-life survival based on maternal treatment or offspring environment.
Opposing selection on anti-predator behaviours from historic and novel
invasive predators may confound the potential of maternal glucocorticoids
to adaptively influence offspring behaviour. Our test of the phenotypic
outcomes of transgenerational glucocorticoid effects across risk
environments provides important insight into the context-specific nature
of this phenomenon and the importance of understanding both current and
historic evolutionary pressures.