Fig. 4

Track metrics. Diagram of successive hypothetical location fixes through (a) time and (b) space. a In order to calculate changes in track metrics through time, it is often necessary to regularise recorded ‘fixes’ (locations) to a constant time step. The resulting regularised fixes are normally connected in space with linear interpolation. b Diagram shows two metrics commonly used in movement analyses. Change in bearing (turning angle) is a measure of path sinuosity, whilst the displacement distance between temporally-regularised location fixes can give an estimate of ground speed. By examining changes to these metrics over time different movement patterns can be identified