The genetic basis for social network traits in the wild.

Sociality is fundamental for many species, linked to an individual’s survival and reproductive success. The evolution of social behaviours has been studied, especially in complex social animals such as birds. However, discerning the genetic basis of these behaviours has been difficult due to the lack of ecological validity and life-history in controlled environments. In wild populations, however, there are the challenges of getting accurate pedigree and behavioural data. This paper used data from a long-term wild sparrow population in which we tracked the social behaviour and genetic pedigree, to assemble social networks. Here, we estimated the genetic architecture of three social network metrics—degree, strength, and betweenness—as a method of characterising social behaviour. The results show a clear genetic component, with heritability values of 8%, 6%, and 1.7% for strength, degree, and betweenness respectively. This study expands our understanding of how sociality is inherited from controlled settings to wild populations, showing a link between genetics and social behaviour. The finding of a negative genetic correlation between strength and degree indicates a more complex genetic relationship underlying these social traits, calling for more research to understand the ecological and evolutionary impacts of these findings. Our results clearly show a genetic basis for social interactions in sparrows, inviting more research into sociality in other bird and non-bird species.