Communication of Food Location Between Human and Dog (Canis Familiaris)

Two domestic dogs (Canis familiaris) participated in a series of studies in which they communicated with a human about the location of hidden food. In the first study both dogs were able to follow human pointing reliably to one of several locations where food was hidden, both in front of them and behind them. They also showed some skills at following human gaze direction in this same task, when both head and eyes indicated the same location. They did not follow eye direction when it conflicted with head direction. A second study clearly ruled out a low-level visual tracking explanation for at least one of the subjects. In a third study one of the two dogs was able to lead a naive human to one of three locations containing food consistently, mainly by barking and orienting its body to the food. The subject did not behave differently, however, when the human turned his back or covered his eyes; he continued to orient to the food and bark under all conditions. In a fourth study in which more clearly visual signals were involved, both subjects strongly preferred to drop a retrieved object at the front of, rather than at the back of, the human — even when the human turned his back so that subjects had to bring the object around his body upon return. The knowledge of human pointing and gaze direction displayed by these two domestic dogs is in many ways comparable to that displayed in experimental studies by nonhuman primates.