Fig. 4

Longitudes (upper panel) and latitudes (lower panel) of a track of a tree swallow as estimated from 2-min fixing interval data by classic approach (GeoLight, dots) and FLightR. The medians of twilight positions estimated by FLightR are shown with accompanying quartile ranges and 95 % credible intervals. Note absence of the latitudinal positions from GeoLight during the equinoxes (shown by red vertical lines)