Fig. 3. Example paths of four return flights at early and late times relative to sunrise and sunset. In each plot, the flight path is in black, with white markers to indicate the sample points. The nest entrance is shown as a cylinder on the right wall, and two-dimensional projected flight paths are shown as gray shadows on the right, left and bottom walls. Luminance in the early morning was 1.1x10^–4 cd m^–2 and the landing lasted 11.4 s; late morning was at 1.9x10^–3 cd m^–2 and the landing lasted 4.7 s; early evening was at 3.9x10^–3 cd m^–2 and the landing lasted 1.8 s; and late evening was at 3.9x10^–4 cd m^–2 and the landing lasted 16.2 s. Each grid square is 10 cm per side.