Figure 1.

Overhead schematic view of the test arena. Birds entered the test arena from the release box (RB). The room contained four novel objects placed at the centre of a blue chalk circle (approx. 55 cm diameter) drawn on the floor of the arena (O1–O4). The test arena was divided into an additional 17 sections; divisions between sections were visually estimated by observers during data collection using the relative size of the duck (i.e. distances are approximated in duck lengths; dl, length from beak tip to tail tip).