Considering appropriate replication in the design of animal social network studies

Abstract

Social network analysis has increasingly been considered a useful tool to interpret the complexity of animal social relationships. However, group composition can affect the contact structure of the network resulting in heterogenic variation at the group level. Replication in contact network studies is rare but is essential for valid hypothesis testing and inference in social contact networks. Social contact data were collected from replicated networks of cattle before and after the application of a social disturbance treatment and the impact of varying the number of replicates in the study was investigated. Subtle but consistent changes in animal contact patterns were detected after the application of a social disturbance treatment demonstrating that replicated animal contact networks are a sensitive tool to investigate biological effects in animal social systems. The analysis demonstrates that reducing the number of networks observed in the study would reduce the probability of detecting treatment differences for social behaviours and social network measures even if the total number of animals was kept the same. This is the first study to quantify within- and between-group variation in animal social contact behaviour, assess its impact on the precision of treatment differences, and consider the likely implications for hypothesis testing.