Summary of seabird assemblages.

Dominant species were defined as those summing to ≥ 50% of species’ relative density for each assemblage. No dominant or co-dominant species are listed for the singles assemblage (Fig 4), as five species were needed to meet the ≥ 50% relative density threshold. Mean relative density relates to all cell-days within an assemblage. The silhouette coefficient assessed each cluster’s distinctness or ‘goodness’ where 1 indicates ideal clustering, 0 indicates that observations are between two clusters (cluster is not highly distinct), and -1 indicates observations are in the wrong cluster. Cell-day = a single 10 x 10 km cell with seabird observations in a given day.