Maternal effects and population regulation: maternal density-induced reproduction suppression impairs offspring capacity in response to immediate environment in root voles Microtus oeconomus

1. The hypothesis that maternal effects act as an adaptive bridge in translating maternal environments into offspring phenotypes and thereby affecting population dynamics has not been studied in the well-controlled fields. 2. In this study, the effects of maternal population-density on offspring stress axis, reproduction and population dynamics were studied in root voles (Microtus oeconomus). Parental enclosures for breeding offspring were established by introducing 6 adults per sex into each of 4 (low density) and 30 adults per sex into each of another 4 (high density) enclosures. Live-trapping started 2 weeks after. Offspring captured at age of 10-20 days were removed to laboratory, housed under laboratory conditions until puberty, and subsequently used to establish offspring populations in these same enclosures, after parental populations had been removed. Offspring from each of the 2 parental sources were assigned into 4 enclosures with 2 for each of the 2 density treatments used in...