The functions of song in the serin

The function of song in the serin Serinus serinus was investigated by measu ring Variation in singing time and song flights by the male, and nest build ing by the female during the prelaying and laying period, and by correlatin g nest building, extra-pair copulation attempts and chasing of the female w ith male singing time and song flights between pairs. Both singing time and nest building varied in relation to the female fertile period, peaking at day -4. Moreover, nest-building activity correlated with singing time, but not song flights, between pairs. This suggests that song may have a functio n in stimulating the female to nest build or begin rapid yolk deposition. P air copulations were not correlated with singing time or song flights eithe r over days relative to laying or between pairs and pairs were not more lik ely to copulate in a given minute of observation when the male had sung in the previous minute than when he had not. However, extra-pair copulation at tempts and chasing of the female showed a tendency to be negatively correla ted with song flight but not singing time, between pairs. This suggests tha t song flight may have a function in discouraging sexual competition from o ther males.