Figure 3.
Track of a Brent Goose, one of a flock of 36, shown in Google Earth from the KML file. The observer's position on the shore is marked ‘Vector’, and the anemometer was nearby. This goose was tracked for 2 min 16.8 s, for a ground distance of 1760 m. There were 16 observations (0–15) giving 15 air speed estimates, which were averaged to get the Run Mean and s.d. for the air speed (14.5 ± 0.953 m s−1). The wind, from a single anemometer reading immediately after the run, was 2.3 m s−1 from 246° (True), measured at 7.2 m above the water surface. The corrected wind (used to calculate the air speed) varied between 1.4 and 2.5 m s−1 as the goose's flying height varied between 1.1 and 10.1 m. This track is typical of 53 that were obtained for this species. (Online version in colour.)