Divide and conquer: when and how should competitors share?

Abstract

When two individuals are unwilling to fight over a valuable resource, then they may obtain it with equal probability, or they may choose to divide the resource in some way. Although both strategies have been observed in nature, modelers have so far implicitly assumed that their long-term payoffs are the same. First we show that increasing returns to size in the value of a resource favor random allocation over sharing, whereas diminishing returns favor the reverse. Next we extend our approach to understand the conditions under which sharing will evolve when contestants vary in their resource-holding potential. We show that although closely matched individuals are more likely to share, it is by no means a prerequisite when contestants have limited information about one another's abilities. Collectively, our models support recent observations of physical sharing as a solution to conflict resolution, and elucidate the conditions under which sharing will arise.

Contests over reproductive resources in female roller beetles: Outcome predictors and sharing as an option

“…Food sharing has been observed in different animal species [ 62 – 65 ]. Even when both contenders play the same strategy, there usually are asymmetries increasing the probability that one of the contenders will keep all or most of the resource, but sharing remains a likely ESS in such circumstances and the stronger opponent should be less willing to divide the contested resource [ 37 ].…”

The evolution of respect for property

“…However, an alternative endpoint to a dispute is to share the contested resource (Chamorro‐Florescano et al ., ; Eswaran & Neary, ). Mesterton‐Gibbons & Sherratt () recently extended the Hawk–Dove model to understand when and how sharing should evolve, and although they considered potential differences in RHP, they did not consider the effects of the more fundamental role asymmetry of owner and intruder. As physical sharing is an intuitively reasonable solution to conflict resolution that is occasionally observed, and as theory has already demonstrated that a nonfighting convention can maintain partitioning of space in the presence of a landmark (Mesterton‐Gibbons & Adams, ), it would be of interest to elucidate the effect of role asymmetry on physical sharing.…”