Variation in singing activity during the breeding cycle of the European starling Sturnus vulgaris.

We examined the pattern of song output of male European starlings during different stages of the breeding cycle. Song activity dropped dramatically at pairing, suggesting that the song has an important mate-attraction function. Singing in the nest box occurred almost only when males were unpaired and when prospecting females were in the vicinity of the nest box. Pairing in starlings had several other effects on male behaviour: the occurrence of wingwaving (a visual display sometimes associated with singing) and of carrying green nest materials dropped significantly after pairing. Unpaired males sang significantly more close (less-than-or-equal-to 1 m) to the nest box than paired males. After pair formation, an increase in singing activity was observed in the period coinciding with the presumed fertile period of the female. Evidence is presented that by singing males try to stimulate their females to solicit copulations during this period. Monogamous males almost completely stop singing after the egg laying period, whereas males attempting to become polygynous start/continue singing at another nest box at a level comparable to that of unpaired males.