Data from: Asynchronous hatching in the burying beetle, Nicrophorus quadripunctatus, maxmises parental fitness

Life history theory predicts that natural selection favours parents who
balance investment across offspring to maximize fitness. Theoretical
studies have shown that the optimal level of parental investment from the
offspring's perspective exceeds that of its parents, and the
disparity between the two generates evolutionary conflict for the
allocation of parental investment. In various species, the offspring hatch
asynchronously. The age hierarchy of the offspring usually establishes
competitive asymmetries within the brood and determines the allocation of
parental investment among offspring. However, it is not clear whether the
allocation of parental investment determined by hatching pattern is
optimal for parent or offspring. Here, we manipulated the hatching pattern
of the burying beetle Nicrophorus quadripunctatus to demonstrate the
influence of hatching pattern on the allocation of parental investment. We
found that the total weight of a brood was largest in the group that
mimicked the natural hatching pattern, with the offspring skewed towards
early hatchers. This increases parental fitness. However, hatching
patterns with more later hatchers had heavier individual offspring
weights, which increases offspring fitness, but this hatching pattern is
not observed in the wild. Thus, our study suggests that the natural
hatching pattern optimizes parental fitness, rather than offspring
fitness.