Polla, E. J., Grueter, C. C., & Smith, C. L. (2018). Asian elephants (Elephas maximus) discriminate between familiar and unfamiliar human visual and olfactory cues. Animal Behavior and Cognition, 5(3), 279-291. https://doi.org/10.26451/abc.05.03.03.2018.

Social animals use individual identity cues to form and maintain social relationships with conspecifics. This ability to discriminate between individuals extends to heterospecifics in some social mammals. The aim of this study was to determine if Asian elephants (Elephas maximus) could differentiate between familiar and unfamiliar people using visual, auditory, and olfactory cues independently. Two female Asian elephants at the Perth Zoo were tested with stimuli generated from six humans. Video playbacks, auditory playbacks and pieces of worn shirts were used to present familiar and unfamiliar human stimuli to the elephants using a simultaneous two-choice task. Trunk reach duration and trunk reach frequency were used as measures of the elephants' interest in the stimuli. The elephants’ trunk reach durations revealed a significant difference between familiar and unfamiliar human stimuli using visual cues alone, with significantly more trunk reaching toward familiar human stimuli. No significant difference in trunk reach duration was seen between familiar and unfamiliar human stimuli for auditory or olfactory cues. Trunk reach frequency revealed a significant difference between familiar and unfamiliar human stimuli for visual and olfactory stimuli, with a greater frequency of trunk reaching towards familiar stimuli for both modes. No significant difference in trunk reach frequency was seen between familiar and unfamiliar human stimuli for auditory cues. This is the first study to use video playbacks with any species of elephant and demonstrates a potential new method for cognitive testing in this species. The results suggest that familiar humans may be important to zoo-housed Asian elephants.

Discrimination; Elephant; Elephas maximus; Heterospecific; Unimodal; Visual; Olfactory