FEMALE PIED FLYCATCHERS RESPOND DIFFERENTLY TO SONGS OF MATES, NEIGHBORS AND STRANGERS

In a field experiment we show that female pied flycatchers, Ficedula h ypoleuca, can learn male song quickly. Of the 16 females that responde d to playback of mate's song and stranger's song, 13 responded only, o r approached sooner and stayed longer in response to the song of their own mate. Of these females 11 females responded solely to their own m ate's song. The number of days the females had been mated had no effec t on their response (range 1 to 7 days, median 3). The result may be e xplained as females recognizing their mates' song or that they respond ed to familiar songs. In a second set of experiments, we therefore tes ted females with a neighbour's song and a stranger's song, broadcastin g the neighbour's song either from the direction where he usually sang or from the opposite direction. Only 8 of 19 females responded to pla yback; when the song was broadcasted from the direction where the male usually sang, none of the females responded, while 8 of 12 females re sponded by approaching and staying near the speaker during the trials when the song was broadcasted from the opposite direction. Thus, femal e pied flycatchers show individual recognition of male neighbours as h as been shown in males of some other species. We therefore infer that the strong response to mates' song may also indicate individual recogn ition. It could be advantageous for females to respond to both mates a nd to neighbours but for different reasons, i.e. mate defence and terr itory defence, respectively.