Stability and change in gartersnake social networks across ontogeny

Abstract

AbstractDevelopmental studies of sociality in non‐human animals can offer important insights into the evolution, function, and plasticity of social behavior, especially in understudied species. We examined the development of social behavior in gartersnakes. We hypothesized that social interactions change as snakes age, but are relatively stable in the short term. To assess developmental changes in social patterns, we examined the social tendencies of a group of 6 eastern gartersnakes over the first year and a half of their lives. We placed the snakes in an arena for 8 days and recorded the time that they spent in physical proximity to each other. We repeated this 8‐day process 7 times across the snakes’ development. We looked at changes in association patterns and individual differences in sociality (i.e., network position), and examined the effect of group size reduction on social behavior. We found that individuals tended to show repeatable network position across time, but there was a behavioral divide between younger snakes and mature snakes. When male snakes reached sexual maturity, they began initiating most social interactions. Additionally, group member attrition caused the networks to tighten, and the population reduction in combination with sexual maturity created stable social networks. This research shows that social context can have important effects on sociability, and that even a species without permanent social groups will be influenced by its social environment.