Jackdaws' behavioural data for experimental stage 3 (choice between mirror and cardboard compartments).

Behavioural data have been standardized to calculate each value per hour. In each case, the first value shows the number of bouts performed in front of the cardboard and the second those performed in front of the mirror. Data has been calculated as the mean value of the six sessions performed in the box separated in two compartments. Looks behind the mirror in these experimental sessions, in which the mirror (or the cardboard) is on the wall, involve going to the edge of the mirror and have a lateral look.*: The jackdaw Blue spent most of its time in the corridor without entering any of the compartments. For information on sex and status (captured in the wild or hand reared in the laboratory) of each individual see Table 1.