Group-level cooperation often poses a social dilemma in which joint action may be difficult to
achieve. Theoretical models and experimental work on humans show that social incentives …

In numerous social species, males direct aggression towards female group members during
intergroup fights, and this behaviour is commonly thought to function as mate guarding, even …

In social species, fighting in intergroup conflicts is one of the riskiest cooperative activities
group members engage in, particularly for individuals of the smaller sex. In a number of …

The energetic costs and benefits of intergroup conflicts over feeding sites are widely
hypothesized to be significant, but rarely quantified. In this study, we use short-term …

Intergroup interactions in social animals can vary from hostile to affiliative and may be
influenced by factors such as competitive ability, resource values and existing intergroup …

In many social species, group members cooperate to defend a communal home range.
Fighting in between-group conflicts carries an opportunity cost, a risk of injury or death, and …

Habitat-wide depletion of food leads to scramble feeding competition and animals can
mitigate costs with behavioral adjustments in ranging and activity budgets. In seasonal …

Socioecological theory predicts that larger groups are able to gain better access to
resources because of their numerical advantage in intergroup contests. Nevertheless, the …

Objectives Social animals often have dominance hierarchies, with high rank conferring
preferential access to resources. In primates, competition among males is often assumed to …

Intergroup relationships vary greatly among primate species from peaceful intermingling in
some species, to the consistent defense of territorial borders in others, to ritualized signaling …