Are California Sea Lions (Zalophus californianus) Sensitive to the Attentional State of their Caretakers?

摘要

Human-animal relations appear in various contexts (homes, farms, zoos, aquatic parks, etc.) possibly favoring the emergence of the ability to understand heterospecific communication signals in several species. Studies show that dogs (Canis familiaris) have developed the ability to attribute attention to humans, reading their bod y, head and gaze cues. Horses (Equus caballus) and other species including African gray parrots (Psittacus erithacus) show this ability too. Here, we asked if California sea lions (Zalophus californianus) can discriminate the attentional state of their caretakers. Four sea lions were tested in three increasingly complex experiments requiring them to make a choice between an attentive versus an inattentive caretaker. The first test asked whether sea lions could attribute attention to a human facing them versus facing away. In the second test, the caretaker's head orientation towards the sea lio n served as the attentional cue. In the final test, the inattentive caretaker wore dark sunglasses. The results were heterogeneous and showed a higher rate of success than failure in the test 1, but the opposite in test 2. The results in the test 3 were not significant. Furthermore, the latency measures suggested that the subjects did not understand the tasks. It therefore appears th at in the situation used here sea lions mainly focused their attention on the experimenter's bod y orientation; the head did not seem to be a pertinent cue.