Increased allocation to reproduction reduces future competitive ability in a burying beetle

1. The existence of a trade-off between current and future reproduction is a fundamental prediction of life-history theory. Support for this prediction comes from brood size manipulations, showing that caring for enlarged broods often reduces the parent’s future survival or fecundity. However, in many species, individuals must invest in competing for the resources required for future reproduction. Thus, a neglected aspect of this trade-off is that increased allocation to current reproduction may reduce an individual’s future competitive ability.

2. We tested this prediction in the burying beetle, Nicrophorus vespilloides, a species where parents care for their offspring and where there is fierce competition for resources used for breeding.

3. We manipulated reproductive effort by providing females with either a small brood of 10 larvae or a large brood of 40 larvae and compared the ability of these females, and virgin females that had no prior access to a carcass, to compete for a...