Fig. 4

Net error between (GPS-corrected) dead-reckoned and GPS positions for a track from 5 African lions. a Maximum net error (m) between ground-truthed GPS and time-matched dead-reckoned positions after one iteration of correction, both as a function of GPS correction rate [one correction per 1—(red), 12—(green) and 24—(blue) hours] and underlying m-coefficient used to determine the DBA-derived speed. Data from 5 lions (individual denoted by symbol shape) over a period of 12 days. Note that the difference in error varies according to individual, initial speed estimate and the rate of correction. b Net error between dead-reckoned positions and all available GPS fixes, according to correction rate (data from the same 5 lions), subsequent to the iterative procedure of GPS correction (maximum distance between GPS fix used in correction procedure and according dead-reckoned position < 0.01 m). Boxes denote the median and 25–75% interquartile range with a blue ‘loess’ smooth line. Whiskers extend to 1.5 * interquartile range in both directions