Abstract

Canid and human barks and growls were examined in videotapes of 24 humans (Homo sapiens) and 24 dogs (Canis familiaris) playing with familiar and unfamiliar cross-species play partners. Barks and growls were exhibited by 9 humans and 9 dogs. Dogs barked and (less often) growled most frequently when being frustrated by humans and/or engaged in competitive games, and less often when being chased or inviting chase, and being instigated or captured. Dogs never growled when playing with an unfamiliar human, and humans did so rarely when playing with an unfamiliar dog. Humans growled and (less often) barked most frequently when chasing and capturing the dog, less often when engaging in competitive games, being frustrated by the dog, and/or instigating the dog, and rarely when showing or throwing an object. Dog barks were most often requests for the human to make an object available to the dog. Dog growls were often pretend threats when competing for an object or being frustrated by the human’s actions. Human barks and growls were typically pretend threats, and were sometimes used to emphasize simultaneous behaviors. Human barks and growls allow humans to connect with their canid partner.