title: Social motivation and conflict resolution tactics as potential building blocks of sociality in cichlid fishes.
abstract: Even closely related and ecologically similar cichlid species of Lake Tanganyika exhibit an impressive diversity of social systems, and therefore these fishes offer an excellent opportunity to examine the evolution of social behaviour. Sophisticated social relationships are thought to have evolved via a building block design where more fundamental social behaviours and cognitive processes have been combined, incrementally modified, and elaborated over time. Here, we studied two of these putative social building blocks in two closely related species of cichlids: Neolamprologus pulcher, a group-living species, and Telmatochromis temporalis, a non-grouping species. Otherwise well matched in ecology, this pair of species provide an excellent comparison point to understand how behavioural processes may have been modified in relation to the evolution of sociality. Using social assays in both the laboratory and in the field, we explored each species' motivation to interact with conspecifics, and each species' conflict resolution tactics. We found that individuals of the group living species, N. pulcher, displayed higher social motivation and were more likely to produce submission displays than were individuals of the non-grouping species, T. temporalis. We argue that the motivation to interact with conspecifics is a necessary prerequisite for the emergence of group living, and that the use of submission reduces the costs of conflict and facilitates the maintenance of close social proximity. These results suggest that social motivation and conflict resolution tactics are associated with social complexity, and that these behavioural traits may be functionally significant in the evolution and maintenance of sociality.
authors.affiliation: Department of Psychology, Neuroscience, & Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada.
authors.forename: Sigal
authors.initials: S
authors.lastname: Balshine
authors.affiliation: School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
authors.forename: Marian Y L
authors.initials: MYL
authors.lastname: Wong
authors.affiliation: Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, QC, H3A 1B1, Canada. Electronic address: adam.reddon@mcgill.ca.
authors.forename: Adam R
authors.initials: AR
authors.lastname: Reddon
mesh_terms: D000374:Aggression / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D023681:Cichlids; D009042:Motivation / Q000502:physiology*; D012919:Social Behavior; D012930:Social Dominance
keywords: Aggression; Cooperative breeding; Group living; Lake Tanganyika; Sociality; Submission