Multiple Parameters in the Territorial coo of the Collared Dove: Interactions and Meaning

Abstract

The perch-coo of the collared dove (Streptopelia decaocto) is used as a territorial signal. We investigated the perception of acoustic variation in the coos by testing the responsiveness to playback in the field. Earlier experiments showed that both temporal and spectral features played an important role in eliciting a behavioural response. In the present study, we used playback experiments to examine whether the impact of temporal features interacts with the impact of spectral features. We show that the increased response level elicited by the presence of frequency modulations is independent of the positioning of frequency modulations within a coo. We conclude that the individual parameters contribute relatively independently of each other to the response. Furthermore, we discuss the functional interpretation of the behavioural response to temporal and spectral features. The nature of inter- and intra-specific variation, and the impact on playback responses may suggest that particular parameters contribute primarily to one function, whereas other features contribute primarily to another. Nevertheless, functions, such as species recognition and quality assessment, may depend on multiple parameters, and there is no evidence for different functions to be separated in specialized processing centres. The concepts of species recognition and quality assessment have to be regarded as labels attached to a particular part of the range of the behavioural response.