Social associations are predicted by nest proximity but not kinship in a free-living social parrot

Abstract

Social associations among conspecifics are typically non-random, often being a function of relatedness, familiarity, or spatial distributions. The aim of this study was to combine field observations with molecular genetic techniques and social network analysis to investigate the predictors of social associations in free-living monk parakeets, Myiopsitta monachus. Monk parakeets are non-territorial parrots whose nests are often aggregated, with relatives clustered in kin neighbourhoods and within cooperatively breeding groups. First, we characterized social associations when away from the nest, showing that individuals typically had a few strong social ties. Second, we investigated whether these social associations were related to nest proximity or genetic relatedness. The strength of association decreased with increasing inter-nest distance, but there was negligible influence of relatedness on the strength of associations. These patterns did not differ between same-sex and opposite-sex dyads. Finally, we investigated whether members of breeding pairs were close social associates, finding that in most cases the closest associate of an individual was their mate, although social bonds also existed outside of the pair; members of breeding groups also associated closely when foraging. Social associations are poorly known in parrots owing to methodological challenges, hence our results add to the limited knowledge of sociality in this taxon.