LAUSR

Interspecific communication provides good opportunity for studying signal evolution. In this theoretical paper, we hypothesized that vocal signaling in dogs may show specific changes that made it more suitable for interspecific communication in the anthropogenic niche. We assumed that (1) some dog vocalizations will diverge from the corresponding exemplars of wolves; (2) they provide comprehendible affective, indexical, and contextual information for humans; (3) some aspects of dog vocalizations are more typical for the interspecific than for the intraspecific domain. We found that the most unique type of vocalization in the dog is barking. We proved that human listeners can contextually categorize dog barks, as well as attribute distinct inner states of dogs based on the barks. We found that dogs are sensitive to both contextual and individual-specific features of other dogs’ barks. However, dogs showed almost no response to the bark emitted in isolation, which is one of the easiest to recognize by humans, indicating the possibility of a specific, new communicative role for barks, not present in its original function. Our conclusion is that the qualitative and quantitative proliferation of barks can be explained by mechanisms of evolution such as ritualization and adaptive radiation. Barks became suitable for conveying a more various set of information than the original barks of wolves did. Barks also became typical in such contexts where originally they were not used – such as the contact seeking calls of isolated specimens, apparently targeted at the human, and not at a canine audience.