Biological markets in cooperative breeders: quantifying outside options

Area of Science:

• Evolutionary Biology
• Behavioral Ecology
• Social Insects

Background:

• Cooperative societies involve subordinates helping dominant breeders raise offspring, foregoing their own reproduction.
• Traditional models assume solitary breeding is the only alternative to helping, often an unfeasible option.

Purpose of the Study:

• To investigate the alternative nesting options available to subordinate paper wasps.
• To test the fitness payoffs of helping versus alternative strategies.
• To evaluate the role of biological market theory in explaining cooperative breeding.

Main Methods:

• Large-scale field experiments were conducted on paper wasps (Polistes dominula).
• Alternative nesting options and their fitness payoffs were assessed.
• Experimental removal of helpers was used to gauge replacement costs.

Main Results:

• Subordinate wasps possess high-quality alternative nesting opportunities with fitness payoffs comparable to their current roles.
• These payoffs significantly exceed those from solitary breeding.
• Experimental removals indicated that subordinates are difficult for dominants to replace, suggesting costs associated with rejection.

Conclusions:

• Cooperative breeding in paper wasps is influenced by the availability of attractive alternative options, not solely by the lack of solitary breeding success.
• Biological market theory, incorporating partner choice and competition, is essential for understanding helping behavior in these societies.
• Traditional models may overestimate the incentive to help and underestimate reproductive concessions needed to retain subordinates.