To test the mate attraction hypothesis and the territory defence (establishment) hypothesis in the Whitethroat Sylvia communis, I studied the pattern of vocal activity in the different phases of the breeding cycle in 1995 and 1996. Furthermore the response of unmated and mated males to playback was studied in 1997. The low “perch song” activity and “flight song” activity of mated males compared to unmated males suggest that song was used in mate attraction. The perch and flight song activity in the morning tended to increase during the season but only significantly in 1996. The perch song was also used in territorial defence as suggested by unmated males responding to the playback with increased song activity. The diving song was apparently used in courtship of the female, since most diving songs were directed towards females. In mated males the dscharp-call was the most frequent vocal behaviour and mated males primarily used this call in response to playback. The more discreet vocal behaviour of mated males suggests that males use a silent strategy.
song function, silent strategy.