Consistency of animal social networks after disturbance

Abstract

Social networks encompass both individual and group phenotypes that have been shown to covary with fitness in several species. In order for network characters to be evolutionarily important, they must reliably reflect properties of an individual or groups of individuals; however, it is unknown whether network traits are consistently expressed at either level. To determine if measurable components of individual social network position were repeatable and if the network structure as a whole was consistent in Bolitotherus cornutus (the forked fungus beetle), we constructed 8 experimental populations. Half of the populations were disturbed between 2 observation periods. Two individual network metrics (strength and betweenness) were significantly repeatable across time in all treatments; a third (clustering coefficient) was not. At the network level, all 3 metrics changed more in undisturbed than disturbed networks. These findings suggest that individual network position can be a consistent property of individuals that is resilient to disturbance and could experience selection in a predictable fashion. However, group network structure seems to change over time unless reset by disturbance.