title: Relatedness and helping in fish: examining the theoretical predictions.
abstract: Many studies have attempted to explain the evolution of cooperation, yet little attention has been paid to what factors control the amount or kind of cooperation performed. Kin selection theory suggests that more cooperation, or help, should be given by relatives. However, recent theory suggests that under specific ecological and demographic conditions, unrelated individuals must 'pay to stay' in the group and therefore may help more. We tested these contrasting predictions using the cooperatively breeding fish, Neolamprologus pulcher, and found that the degree of work effort by helpers depended on which helping behaviours were considered and on their level of relatedness to the breeding male or female. In the field, helpers unrelated to the breeding male performed more territory defence, while helpers unrelated to the breeding female contributed less to territory defence. In the laboratory, unrelated group members helped more. Our work demonstrates that a number of factors in addition to kinship shape cooperative investment patterns.
authors.affiliation: Animal Behaviour Group, Department of Psychology, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Stiver
authors.forename: Petra
authors.initials: P
authors.lastname: Dierkes
authors.forename: Michael
authors.initials: M
authors.lastname: Taborsky
authors.forename: H Lisle
authors.initials: HL
authors.lastname: Gibbs
authors.forename: Sigal
authors.initials: S
authors.lastname: Balshine
mesh_terms: D000818:Animals; D001837:Body Weights and Measures; D023681:Cichlids / Q000235:genetics / Q000502:physiology*; D003299:Cooperative Behavior; D005260:Female; D005618:Fresh Water; D008297:Male; D012098:Reproduction / Q000235:genetics; D012641:Selection, Genetic; D012737:Sex Factors; D012744:Sex Ratio; D013731:Territoriality; D015024:Zambia