Figure 9.

Experimental set-up: In the aviary room, young birds housed in the three different aviaries could hear and see each other. In the soundproof chambers, birds were housed individually or in pairs. All the experimental birds received the same auditory exposure. Birds in the soundproof chambers could hear all the songs from the birds in the aviaries via microphones and loudspeakers. (M, wild males; m, experimental males; f, experimental females; LS, loudspeaker; micro, microphone; →, direction of auditory information transfer (from Poirier et al., 2004).