More than noise? - Field investigations of intraspecific acoustic communication in dogs (Canis familiaris)

摘要

Besides being a widely investigated behavioural phenomenon, barks of dogs often represent a factor of nuisance for people. Although some argue that dog barking has no or only minimal communicative function, it was shown recently that these acoustic signals carry various information that humans can decipher. However, apart from a few laboratory studies, until now no targeted research has been done about the communicative role of barks in the intraspecific domain. In this field experiment companion dogs were tested with bark playbacks at home, in a suburban environment. From a hidden sound system, placed near to the gate outside of the property, each subject was exposed to pre-recorded barks of an unfamiliar and a familiar dog. Barks for the playbacks were recorded in two different contexts: when the dog was either left alone or when it was barking at a stranger at the fence. We found differences in the behaviour of dogs depending on both the familiarity and context of the playback barks. The position of the dogs (near the house or near the gate) was mainly influenced by the context of the barks (p = 0.011), in a significant interaction with the familiarity of the barking dog (p = 0.020). Subjects stayed at the gate (nearest to the source of the sound) the longest when they heard an unfamiliar dog barking at a stranger (P-adj = 0.012). Meanwhile they stayed at the house mostly during the barks of a lonely unfamiliar dog (P-adj = 0.001). Dogs oriented more towards the house (where the familiar dog stayed during the experiment) when they heard the familiar dog's barking (p = 0.019). Subjects barked more often when they heard the 'stranger' barks, independently of the familiarity of the caller (p = 0.035). As a conclusion, dogs seemingly distinguished among the callers based on familiarity and between the contexts of the barks. This is the first study on companion dogs in their natural environment that found evidence that dogs are able to extract detailed information from the barks. The relevance of our findings for the management of excessive bark is discussed