Identifying the role that individual animals play in their social network

TL;DR

This study applies human social network analysis techniques to bottlenose dolphins, revealing community structures, roles of brokers, and similarities and differences with human networks, enhancing understanding of animal social organization.

Contribution

It introduces the application of human social network analysis methods to dolphin social data, identifying key individuals and community structures.

Findings

Identification of dolphin communities and subcommunities

Evidence of sex- and age-related homophily in social clustering

Discovery of key brokers crucial for social cohesion

Abstract

Techniques recently developed for the analysis of human social networks are applied to the social network of bottlenose dolphins living in Doubtful Sound, New Zealand. We identify communities and subcommunities within the dolphin population and present evidence that sex- and age-related homophily play a role in the formation of clusters of preferred companionship. We also identify brokers who act as links between subcommunities and who appear to be crucial to the social cohesion of the population as a whole. The network is found to be similar to human social networks in some respects but different in some others such as the level of assortative mixing by degree within the population. This difference elucidates some of the means by which the network formed and evolves.