Wasps Use Social Eavesdropping to Learn about Individual Rivals

• Published in: Current biology Vol. 30; no. 15; pp. 3007 - 3010.e2
• Main Authors: Tibbetts, Elizabeth A., Wong, Ellery, Bonello, Sarah
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 03.08.2020
• Subjects: aggression; cognition; communication network; dominance; individual recognition; learning; public information; social eavesdropping; social information; social intelligence; communication network; cognition; social intelligence; social eavesdropping; learning; aggression; social information; dominance; individual recognition; public information
• ISSN: 0960-9822; 1879-0445; 1879-0445
• DOI: 10.1016/j.cub.2020.05.053

Many animals minimize the costs of conflict by using social eavesdropping to learn about the fighting ability of potential rivals before they interact. Learning about individual conspecifics via social eavesdropping allows individuals to assess potential opponents without personal risk. However, keeping track of a network of individually differentiated social relationships is thought to be cognitively challenging. Here, we test how Polistes fuscatus nest-founding queens use social eavesdropping to assess individual rivals. Bystanders watched conspecifics fight through a clear partition. Then, bystanders were allowed to interact with fighters. Bystander behavior toward fighters was strongly influenced by the observed fight; bystanders were less aggressive toward fighters that were seen to initiate more and receive less aggression. Control trials allow us to reject alternative explanations for the link between observed aggression and bystander behavior, including priming or winner/loser effects. Therefore, P. fuscatus wasps observe and remember a complex network of social interactions between individual conspecifics rather than only paying attention to individuals they interact with directly. Wasps have an impressive capacity to learn, remember, and make social deductions about individuals. These results indicate that insects can have surprisingly complex social lives involving a network of individually differentiated social relationships. •Wasps learn about new individuals by observation alone•Wasps watched fights, then interacted with the same or a different fighter•Wasps were less aggressive to individuals they observed fight well•Social eavesdropping allows individuals to assess rivals with little personal risk Animals often learn about other individuals through direct interactions like fights. Tibbetts et al. show that Polistes fuscatus wasps can use social eavesdropping to learn about potential rivals without direct interactions. Wasps learn, remember, and make social deductions about individuals via observation alone.