The Communal Display of the House‐sparrow Passer Domesticus

Summary. The communal display of the House‐sparrow is described. The display may involve from two to ten or more males, but only one female. In both Hampshire and Holland the display is most frequent in April, uncommon at the beginning of May, rises to a secondary maximum at the end of May, does not occur in August and the first half of September, and reappears in the late autumn. The initiation of the display and the relationship of the birds taking part is discussed. In the instances observed only one bird of each sex was involved in the initial stages. In all cases where the participants have been identified the females have been paired birds. The males have included both paired and unpaired birds; the mate of the participating female has frequently taken a prominent role. It is suggested that the display arises when a male attempts to mount a female which is not ready for coition. A chase takes place, attracts other males and the communal display develops. The occurrence of the display is then related to the sexual relationship between paired birds. It is concluded that the communal display in the House‐sparrow is a true sexual display, which has developed in a social species into a communal display, whereby not only pairs of birds but the whole of the flock may be brought into breeding condition.