Response to interspecific vocalizations is affected by degree of phylogenetic relatedness in Streptopelia doves

Owing to common descent, related species often show similarity in a number of traits, including those involved in communication. As a result signal si milarity and phylogenetic distance are usually inversly, related. However, similarity in signal structure need not correspond with similarity in respo nse to such signals. We tested the hypothesis that individuals are more res ponsive to signals from closely related species than from distantly related ones. We conducted playback experiments on two turtle dove species (Africa n collared-dove, Streptopelia roseogrisea, and vinaceous dove, Streptopelia vinacea) using conspecific and heterospecific vocalizations. Vocalizations were played from species that differed in degree of relatedness and in rel ative geographical distribution This enabled us to separate the effects of phylogeny and those of sympatry. There was an effect of phylogenetic distan ce, with a decrease in response to playback stimuli as phylogenetic distanc e increased. The results also suggest. a minor effect of sympatry, with the response to sympatric species being lower. (C) 2001 The Association for th e study of Animal Behaviour.