title: Individual consistency and context dependence in group-size preference of Eurasian perch.
abstract: Many fish spend a large part of their life in groups. The size of the group influences potential costs and benefits of group living, and depending on context a fish may prefer different group sizes. Group-size preference may also depend on personality, with social individuals expected to prefer larger groups than asocial fish. This study investigates context-dependent group size preference in two populations of a highly social fish, young of the year Eurasian perch. The perch were given a choice between a group of two and a group of eight conspecifics under three different situations: the small group was feeding, the small group had access to shelter, and a control treatment with no extra stimuli. In general, the perch associated more with the large group, but significantly less so during the food treatment. Perceived access to shelter did not affect group size preference compared to the control treatment. Consistent individual differences in social attraction were found within each context, but not among all contexts. Also, an individual's sociability did not correlate with its degree of boldness, indicating a lack of a behavioural syndrome between the two personality traits in the studied populations. The results highlight the importance of considering environmental context when studying social behaviour in obligate social fish, and show the complexity of the concept of sociability as a personality trait by demonstrating context dependence in individual consistency in social behaviour.
authors: Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Sweden; Department of Ecology and Environmental Science, Umeå University, Sweden. Electronic address: gustav.hellstrom@umu.se.
authors: Gustav
authors: G
authors: Hellström
authors: Zoological Institute of the University of Cologne, Department of General Ecology and Limnology, Ecological Field Station Grietherbusch, D-50923 Cologne, Germany; Department of Ecology and Environmental Science, Umeå University, Sweden.
authors: Martina
authors: M
authors: Heynen
authors: Zoological Institute of the University of Cologne, Department of General Ecology and Limnology, Ecological Field Station Grietherbusch, D-50923 Cologne, Germany.
authors: Jost
authors: J
authors: Borcherding
authors: Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Sweden.
authors: Carin
authors: C
authors: Magnhagen
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D010471:Perches / Q000502:physiology*; D012919:Social Behavior