Fig. 3. Foraging behaviour of one common guillemot during one complete foraging trip. (A) The first and (B) the second halves of the trip. The lines indicate the recorded activity of the bird, and its diving depth. Note (i) that the bird did not fly during the time elapsed from diving bout 3 to diving bout 7, and (ii) that it was either active (bouts 1, 2 and 4) or resting (bouts 5, 6 and 7) at the sea surface during dive intervals within diving bouts.