Adaptive consequences and heritable basis of asynchronous hatching in Nicrophorus vespilloides

Asynchronous hatching is an important component of animal reproductive strategies, yet it has been studied almost exclusively in altricial birds. In this study, we provide evidence on the adaptive consequences and the heritable basis of asynchronous hatching in an insect, the burying beetle Nicrophorus vespilloides. Parents of this species breed on carcasses of small vertebrates and provide food in the form of predigested carrion for their offspring. We found that the size of the carcass used for breeding had a significant effect on hatching skew towards the earlier part of the hatching period, suggesting that female parents adjust hatching skew facultatively to the amount of resources available for breeding. Using a full sibling breeding design, we also found that parent family had a significant effect on both hatching skew and hatching spread, suggesting that there is a heritable basis to asynchronous hatching. Finally, we found that hatching spread affected offspring survivorship, providing evidence that asynchronous hatching patterns have adaptive consequences in N. vespilloides. Our study provides valuable new insights into the evolution and ecological significance of asynchronous hatching by providing evidence on the adaptive consequences and the heritable basis of asynchronous hatching in a non-avian species. © 2008 The Authors.