Dominance, sharing, and assessment in an iterated Hawk–Dove game

Abstract

Animals use a wide variety of strategies to reduce or avoid aggression in conflicts over resources. These strategies range from sharing resources without outward signs of conflict to the development of dominance hierarchies, in which initial fighting is followed by the submission of subordinates. Although models have been developed to analyze specific strategies for resolving conflicts over resources, little work has focused on trying to understand why particular strategies are more likely to arise in certain situations. In this paper, we use a model based on an iterated Hawk-Dove game to analyze how resource holding potentials (RHPs) and other factors affect whether sharing, dominance relationships, or other behaviors are evolutionarily stable.We find through extensive numerical simulations that sharing is stable only when the cost of fighting is low and the animals in a contest have similar RHPs, whereas dominance relationships are stable in most other situations.We also explore what happens when animals are unable to assess each other's RHP without fighting, and we compare a range of strategies for this problem using simulations. We find that the most successful strategies involve a limited period of assessment followed by a stable relationship in which fights are avoided, and that the duration of assessment depends both on the costliness of fighting and on the difference between the animals' RHPs. Along with our direct work on modeling and simulations, we develop extensive software to facilitate further testing; and we make it publicly available at https: //bitbucket.org/CameronLHall/dominancesharingassessmentmatlab/.

Social status and previous experience in the group as predictors of welfare of sows housed in large semi-static groups

“…There is evidence that pigs highly involved in reciprocal fights have more skin lesions immediately after mixing, but likewise the strong propensity to receive non-reciprocal aggression is susceptible to increase body lesion severity [ 26 ]. Once established, stable dominance hierarchy among group members can suppress unnecessary fights [ 53 ], which are among the most damaging social interactions, and future agonistic interactions are usually limited to single bites, knocks and threats due to the competition for resource access (e.g., feeding, resting area), hunger, discomfort, irritability or frustration [ 8 , 54 , 55 ]. On days 27 and 29, Resident Subdominants gave numerically more non-reciprocal agonistic acts than their Resident counterparts.…”

Social status and previous experience in the group as predictors of long-term welfare of sows housed in large semi-static groups

“…There is evidence that pigs highly involved in reciprocal fights have more skin lesions immediately after mixing, but likewise the strong propensity to receive non-reciprocal aggression is susceptible to increase body lesion severity (25). Once established, stable dominance hierarchy among group members can suppress unnecessary fights (52), which are among the most damaging social interactions, and future agonistic interactions are usually limited to single bites, knocks and threats due to the competition for resource access (e.g., feeding, resting area), hunger, discomfort, irritability or frustration (8,53,54). On days 27 and 29, Resident Subdominants gave numerically more non-reciprocal agonistic acts than their Resident counterparts.…”

Dominance in humans

“…If players could only act in one way permanently, natural selection will favour a mixture of hawks and doves depending on the value of the resource, each individual's chances of winning, and fighting costs. However, if agents can switch, natural selection can favour the use of even arbitrary differences among pairs to coordinate hawk or dove status, thereby preventing fights [20] For example, in the stable state achieved if all players use the bourgeois strategy, the individual who arrives first at the resource receives it (plays hawk) while the later arrivals are doves. This suppresses costly conflicts and permits the bourgeois to drive out pure hawks and doves.…”