Fig. 1. Laysan albatross Argos track (A), and selected examples of linear (B) and Bézier (C) interpolation of this track (every 10 min). In B and C, the circled cross represents an Argos position that was removed to use as a reference position. The distance between this position and the corresponding interpolated location was calculated for each mathematical algorithm that we used (see Materials and methods). Note the possibility to visualize transit speed in interpolated tracks.