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

Area of Science:

• Evolutionary biology
• Behavioral ecology

Background:

• Life history theory predicts a trade-off between current and future reproduction.
• Brood size manipulations show reduced future survival or fecundity with larger broods.
• Future reproduction may also depend on competitive ability for resources.

Purpose of the Study:

• To test if increased investment in current reproduction reduces future competitive ability.
• To investigate this trade-off in the burying beetle, Nicrophorus vespilloides.
• To determine if reproductive benefits offset the costs of competition.

Main Methods:

• Manipulated reproductive effort by providing females with small (10) or large (40) broods.
• Assessed female competitive ability for a second carcass against a virgin competitor.
• Compared competitive success between females with different brood sizes and virgin females.

Main Results:

• Females caring for larger broods had reduced future competitive ability.
• Females with small broods were better competitors than virgin females.
• Females with large broods showed similar competitive ability to virgin females.

Conclusions:

• Increased allocation to current reproduction can impair future competitive ability.
• The trade-off between current and future reproduction can be mediated by competitive interactions.
• Direct benefits from reproduction, like resource acquisition, can offset some reproductive costs.