Helping in Cyanopica · Why helping others? The role of direct fitness benefits within the social-networks in cooperatively breeding azure-winged magpies

Why helping others? The role of direct fitness benefits within the social-networks in cooperatively breeding azure-winged magpies

"Cooperation is widespread in nature, including our own species, but in many cases it poses an evolutionary paradox with natural selection favouring own success in competition with alternative genetic forms. One main classic explanation is kin selection, i.e. the success of genes promoting copies of themselves not only by means of the reproduction of the bearer but also of its relatives. However, current literature on the evolution of cooperation agrees that kin selection cannot explain the benefits accrued by cooperators in many systems. One main gap is the type of direct benefits that helpers obtain in cooperative breeding systems and how they constitute an evolutionarily stable strategy, provided that natural selection favours defectors over cooperators in unstructured populations. Recent advances show that ""social viscosity"" could maintain benefits for cooperators. Thus, the study of social network structure could potentially explain why cooperation persists. This type of approach can only be tackled after a longterm study at individual level. Birds are good model species for studying cooperation, in particular by investigating the helping behaviour in cooperatively breeding species. For more than 20 years, I have participated in a research team that monitored a population of cooperative breeding Iberian magpie (Cyanopica cooki). I have pedigree data, their reproductive behaviour in helper and breeder roles, and lifetime reproductive success for many birds. Yet, the reason why helpers contribute to rearing other birds' offspring has remained elusive. The objective of this project was to use network approach to previous data plus new monitoring of breeding groups to study: the role of kinship, by using pedigree and genetic analyses; the structure of social networks based on cooperative relationships, to see whether interactions can explain the maintenance of cooperative behaviour from the point of view of reciprocity and generalized reciprocity predictions; potential paternity sharing between breeders and helpers; and the relative roles of different benefits in lifetime inclusive fitness. "

Data: CORDIS, © European Union