Quantifying role of individuals
To determine the role of individuals in the social structure, we calculated standard centrality measures (Wey et al. 2008; Krauseet al. 2010; Pinter-Wollman et al. 2014) for each individual in each social situation and in the aggregate network:
Degree : The number of unique individuals that a vulture interacted with.
Strength : The intensity of interactions of an individual, calculated as the sum of the weights of all the edges that reach a node. Higher values indicate more strongly connected individuals.
Page rank : A score given to a node based on second-order interactions, such that nodes connected to well-connected individuals have a higher score.