Sex Differences in the Persistence of Natal Environmental Effects on Life Histories

"Silver spoon" effects of early environments on adult characteristics [1, 2] and life-history trajectories are thought to be widespread among vertebrates [3-6] and are important because they imply that environments can have cascading transgenerational effects [7, 8]. Here we test for such effects by using a sample of 5425 great tits (Parus major) for which both natal and breeding environments were known in detail. Female life histories were strongly coupled with breeding conditions, but we found little evidence for any persistent effects of the natal environment. In contrast, life span and breeding success in males were influenced by the quality of the environment in which they were raised. Potential explanations for persistent environmental effects in males, but not females, include differential sex allocation benefiting males from high-quality environments and phenotypic plasticity allowing females to optimize reproductive decisions to current conditions, hence masking any residual natal effects. Thus, in contrast to findings of much recent work, persistent effects of the early environment are not all-pervasive and may differ between the sexes within a single species, potentially leading to sex-differential selection. Further work should attempt to understand the conditions under which these transgenerational environmental effects are likely to occur.