Dawn Singing in Pied Flycatchers: Mated Males Sing Highly Versatile Songs in the Early Morning

In the pied flycatcher, singing is thought to be used mainly for attracting females, because males seem to sing very little after pairing. However, I observed a peak of high singing activity in 19 mated males — so-called dawn singing — that had never been reported for the pied flycatcher. Mated males started to sing 1 hr 15 min before sunrise, under poor-light conditions. Their singing activity lasted for 40–50 min and then decreased substantially. I compared songs before pairing and dawn songs after pairing for nine individually marked pied flycatcher males. Dawn songs had significantly higher song versatility and song rate as compared with songs performed before pairing by the same males. I propose that pied flycatcher males use dawn singing to stimulate females for extra-pair copulations, because pied flycatcher females prefer males with greater song repertoires, higher song rates and higher song versatility.