Data for: Fragmentation and disturbance drive montane mixed-flock species roles and interaction strength

Mixed-species flocks are a key facilitative interaction for tropical birds. Forest fragmentation leads to species loss and spatial turnover in these flocks, yet it is unknown how these changes to composition influence within-flock species interactions. We used network analysis to characterize flocking interactions along a fragment-size gradient in the Colombian Western Andes. We asked (1) how patch size, edge density, and vegetation structure explained network measures indicative of flock cohesion, (2) whether changes were driven by flocking species turnover or changes to the frequency of species co-occurrence, and (3) whether nuclear species, those that maintain flock stability and cohesion, changed in importance across the gradient. We constructed weighted social networks from flock compositions observed on 500-meter transects, and then calculated global network measures and the centrality of six nuclear species. Patch size and edge density did not correlate with interspecific co-occu...