Individuals of many species utilise social information whilst making decisions. While
many studies have examined social information in making large scale decisions,
there is increasing interest in the use of fine scale social cues in groups. By
examining the use of these cues and how they alter behaviour, we can gain insights
...
Individuals of many species utilise social information whilst making decisions. While
many studies have examined social information in making large scale decisions,
there is increasing interest in the use of fine scale social cues in groups. By
examining the use of these cues and how they alter behaviour, we can gain insights
into the adaptive value of group behaviours. We investigated the role of social
information in choosing when and where to dive in groups of socially foraging
European shags. From this we aimed to determine the importance of social
information in the formation of these groups. We extracted individuals’ surface
trajectories and dive locations from video footage of collective foraging and used
computational Bayesian methods to infer how social interactions influence diving.
Examination of group spatial structure shows birds form structured aggregations with
higher densities of conspecifics directly in front of and behind focal individuals.
Analysis of diving behaviour reveals two distinct rates of diving, with birds over twice
as likely to dive if a conspecific dived within their visual field in the immediate past.
These results suggest that shag group foraging behaviour allows individuals to
sense and respond to their environment more effectively by making use of social
cues.