Fig. 4

Selected features for the classification of static clusters and directional movement are shown in 3D (top) and projected on maps (bottom) in a colour and size-scale. (a) The eccentricity and the perimeter-to-area ratio of the enclosing ellipse provide information on hull geometry and directional movement. (b) Dense clusters of nearest neighbours were constructed in areas used more frequently. (c) Final classification of static clusters and in-movement location based on thresholds of these features