Figure 2.

Mean foraging trip duration and maximum distance from the colony for 21 Northern Gannet Morus bassanus colonies in relation to colony size and latitude. Black lines show the prediction from a finite population corrected linear model ±95% confidence intervals (grey ribbon) using the mean value of latitude to predict the effect of square-root (√) colony size and vice versa. To visually correct for √colony size, we subtracted the √colony size effect (grey dashed line) from each data point (grey circle) and then added the √colony size effect for the mean √colony size (black circle). See electronic supplementary material, figure S3 for figure 2 with points labelled by colony name.