Multifaceted parental niche construction buffers microbial and competitive challenges and drives offspring dependence in burying beetles

Parents across diverse taxa modify the biotic or abiotic environments of their offspring. Such modifications may constitute ecological inheritance and are central to developmental niche construction, whereby organisms shape developmental conditions and selective pressures experienced by the next generation. Despite its theoretical importance, parental niche construction is often studied under simplified conditions or by focusing on single components of care, limiting our understanding of how multiple parental modifications interact in ecologically relevant contexts and shape offspring development and evolutionary trajectories. Using the burying beetle Nicrophorus vespilloides, we investigated how parents jointly modify chemical and microbial properties of vertebrate carcasses, a highly contested resource on which the beetles larvae develop. We show that under natural microbial and competitive conditions, pre-hatch parental care enhances larval survival and growth, alters cadaveric volatile emissions, and reduces carcass attractiveness to competitors. While soil type initially shapes carcass-associated microbial communities, parental care buffers these environmental effects, creating a more consistent microbiome and thereby increasing larval survival by reducing environmentally induced mortality. Larvae of the related species Ptomascopus morio, which lacks pre-hatch carcass preparation, showed no difference in survival between prepared and unmodified carcasses, whereas N. vespilloides larvae showed reduced survival on unmodified carcasses. This contrast suggests that N. vespilloides larvae have evolved a reliance on a parentally constructed developmental environment. Together, these findings show that parental care can constitute an integrated form of niche construction that reshapes developmental environments, enhances offspring performance, and can promote evolutionary feedbacks leading to increased offspring dependence on parental care.