Field studies of habituation: III. Playback contingent on the response of the white-crowned sparrow

Territorial song was played to pairs of breeding white-crowned sparrows. Presentation of the song was contingent on the song of the resident male. Continuous recordings of an extensive sample of the behaviour of the male and female were made. A predicted increase in behaviour elicited by this playback regime, as compared to an invariant presentation of song every 11 s, did not occur. A large amount of variance was accounted for when the subjects were split into two groups on the basis of the number of songs emitted by the male. This latter result was cross-validated with data from two other studies. These results suggest that there is a male state variable that exerts a strong influence on the behaviour of both the male and female member of the pair.