Data from: Interplay between age-based competitive asymmetries within the brood and direct competition between inbred and outbred offspring in a burying beetle

Theory suggests that intraspecific competition associated with direct
competition between inbred and outbred individuals should be an important
determinant of the severity of inbreeding depression. The reason is that,
if outbred individuals are stronger competitors than inbred ones, direct
competition should have a disproportionate effect on the fitness of inbred
individuals. However, an individual’s competitive ability is not only
determined by its inbreeding status but also by competitive asymmetries
that are independent of an individual’s inbreeding status. When this is
the case, such competitive asymmetries may shape the outcome of direct
competition between inbred and outbred individuals. Here we investigate
the interface between age-based competitive asymmetries within broods and
direct competition between inbred and outbred offspring in the burying
beetle Nicrophorus vespilloides. We found that inbred offspring had lower
survival than outbred ones confirming that there was inbreeding
depression. Furthermore, seniors (older larvae) grew to a larger size and
had higher survival than juniors (younger larvae), confirming that there
were age-based competitive asymmetries. Nevertheless, there was no
evidence that direct competition between inbred and outbred larvae
exacerbated inbreeding depression, no evidence that inbreeding depression
was more severe in juniors, and no evidence that inbred juniors suffered
disproportionately due to competition from outbred seniors. Our results
suggest that direct competition between inbred and outbred individuals
does not necessarily exacerbate inbreeding depression and that inbred
individuals are not always more sensitive to poor and stressful conditions
than outbred ones.