Figure 1

(after [ 103 ] ). A geometric segmentation of a trajectory. Red/pink segments are migration flight, yellow segments are stopovers (one stopover is shown in more detail in the lower right corner). Blue markers indicate end of a stopover. Stopovers are described by staying within a bounded activity radius for at least 2 days. This is a conjunction of a monotone-decreasing criterion (if the sequence (B, C,…, G) stays in a disk of small radius then so does every subsequence, e.g. (D, E, F)) and a monotone-increasing criterion (if the sequence (B,…, G) corresponds to a duration of at least two days then so does every sequence which includes it, e.g., (A, B,…,G, H)).