title: Social deprivation affects cooperative predator inspection in a cichlid fish.
abstract: The social environment individuals are exposed to during ontogeny shapes social skills and social competence in group-living animals. Consequently, social deprivation has serious effects on behaviour and development in animals but little is known about its impact on cooperation. In this study, we examined the effect of social environment on cooperative predator inspection. Predator inspection behaviour is a complex behaviour, which is present in a variety of shoaling fish species. Often, two fish leave the safety of the group and inspect a potentially dangerous predator in order to gather information about the current predation risk. As predator inspection is highly risky, it is prone to conflicts and cheating. However, cooperation among individuals may reduce the individual predation risk. We investigated this complex social behaviour in juveniles of the cichlid fish Pelvicachromis taeniatus that were reared in two different social environments throughout development. Fish reared in a group inspected more often than isolation-reared fish and were more likely to cooperate, i.e. they conducted conjoint inspection of a predator. By contrast, isolation-reared fish were more likely to perform a single inspection without a companion. These results suggest an impairment of cooperative behaviour in isolation-reared fish most probably due to lack of social experience and resulting in lowered social skills needed in coordinated behaviour.
authors.affiliation: Institute for Evolutionary Biology and Ecology , University of Bonn , An der Immenburg 1, Bonn 53121, Germany.
authors.forename: Saskia
authors.initials: S
authors.lastname: Hesse
authors.affiliation: Institute for Evolutionary Biology and Ecology , University of Bonn , An der Immenburg 1, Bonn 53121, Germany ; Department of Fish Ecology and Evolution , Evolution and Biogeochemistry, Seestraße 79 , Kastanienbaum 6047, Switzerland ; Department of Aquatic Ecology, Eawag Centre of Ecology , Evolution and Biogeochemistry, Seestraße 79 , Kastanienbaum 6047, Switzerland.
authors.forename: Jaime M
authors.initials: JM
authors.lastname: Anaya-Rojas
authors.affiliation: Department of Behavioural Ecology, Institute for Ecology and Evolution , University of Bern, Wohlenstr. 50a , Hinterkappelen 3032, Switzerland.
authors.forename: Joachim G
authors.initials: JG
authors.lastname: Frommen
authors.affiliation: Institute for Evolutionary Biology and Ecology , University of Bonn , An der Immenburg 1, Bonn 53121, Germany ; Department of Behavioural Ecology, Institute for Ecology and Evolution , University of Bern, Wohlenstr. 50a , Hinterkappelen 3032, Switzerland.
authors.forename: Timo
authors.initials: T
authors.lastname: Thünken
keywords: cichlids; cooperation; predator inspection; social environment; social isolation