Inter-nest distances drive most but not all social associations in a colonial seabird

Antoine Morel , Eric Vander Wal, Pierre-Paul Bitton

Social and spatial environments shape the way individuals associate and impact their social network structure. However, nowhere are social and spatial mechanisms more likely to be simultaneously entangled and potentially misinterpreted than in colonial species. We colour-banded 124 Atlantic puffins, georeferenced their burrows and tracked their associations on land using a scan sampling approach (regular observation through the plot) during the breeding season to understand how the spatial distribution of the burrows constrained their associations. 

We tested how the distance between nests in a colony affected (i) individual probability of association and the dyadic weight (number of associations between two individuals), and (ii) their community structure (when connections are stronger within rather than among modules). We also tested for the presence of non-random associations across different distances. 

We found that the distance between burrows strongly influenced the social network structure of Atlantic puffins. Individuals associated more often with close neighbours, but there was no evidence of favoured associations. However, contrary to expectation, we found that groups of individuals formed communities and evidence that distant associations with conspecifics were not all random. We suggest that individuals may seek each other out if it provides mutual benefits or have similar spatial and temporal requirements.