Spot longitude versus time for spots with flux deficit higher than 0.1 are shown as white circles overplotted on the map of the spot filling factor obtained by Lanza et al. (2009) from out-of-transit data (their Fig. 4). Different colours indicate different filling factors, with yellow indicating the maximum spot occupancy and dark blue the minimum. The bridges connecting active longitudes are labelled with A, B, and C (see the text).