Figure 6.

The information content of panoramic views as determined by rotIDFs (see §2 for details). (a) Image differences over orientation between a south-oriented panoramic image recorded at the nest (see bottom image on the right) and itself (red), and images recorded to the north of the nest looking south at different distances (0.5 m, green; 1 m, blue; 5 m, yellow; 10 m, black). (b) Same for a north-oriented snapshot at the nest and views recorded to the south of the nest looking north at different distances. Panoramic images are aligned such that nest direction is in the centre. (c) Same for a west-oriented snapshot at the nest and the view at the distant release site further than 100 m east of the nest area (black line and matching frame on right). Blue, rotIDF for a horizontal slice stretching from 22° to 43° above the horizon; green, rotIDF for a horizontal slice stretching from 0° to 22° above the horizon.