The frequency and timing of copulations in the Willow Tit Parus montanus

Abstract

The frequency and timing (in relation to season and time of day) of copulations were studied in the Willow Tit Parus montanus . We monitored 124 pairs in four years. Copulations were solicited by both sexes and they occurred both in the suspected fertile and non-fertile periods of the females. Similarly, there was no significant decline in the copulation frequency after the laying period started. The frequencies of copulations and copulation attempts were estimated as 0.37-0.52/h/pair and 0.21- 0.43/h/pair , respectively . Copulations occurred from 03:42-11 :00 hours, but they peaked early in the morning. No copulations were seen in the afternoon. The results imply that, like in many other territorial species, the copulation frequency of the Willow Tit is relatively low and thus, probably not influenced by sperm competition . Other functions of copulations (in addition to fertilization) and the reasons for early morning copulation peak are discussed.