Fig. 1
From: Pair bonds during the annual cycle of a long-distance migrant, the Arctic Tern (Sterna paradisaea)
Trajectories for the outward (left column) and inward (right column) migrations of each pair plotted on a global orthographic projection. Outward tracks start from the date that the last member of the pair departed. Females, filled circles; males, filled triangles. Points are locations estimated by FLightR and coloured by date according to the colour scale and legend to the right of each pair of orthographic global projections to illustrate the temporal coordination (or lack thereof) of the location of pair members. The points do not include the periods in 24-h daylight and before the start of return migration which are shown as plots of longitude by date in Additional file 1: Fig. S3