Do American Crows Pay Attention to Human Gaze and Facial Expressions?
Article first published online: 17 FEB 2013
© 2013 Blackwell Verlag GmbH
Volume 119, Issue 4, pages 296–302, April 2013
How to Cite
Clucas, B., Marzluff, J. M., Mackovjak, D., Palmquist, I. (2013), Do American Crows Pay Attention to Human Gaze and Facial Expressions?. Ethology, 119: 296–302. doi: 10.1111/eth.12064
- Issue published online: 15 MAR 2013
- Article first published online: 17 FEB 2013
- Manuscript Accepted: 17 JAN 2013
- Manuscript Revised: 7 SEP 2012
- Manuscript Received: 10 JUL 2012
- McIntire-Stennis Cooperative Forestry Research Program
- University of Washington. Grant Number: 3077-01
Interactions between species can lead to the evolution of interspecific communication. Non-verbal communication by humans, both intentional and unintentional, can be interpreted by other species. We tested whether American crows (Corvus brachyrhynchos) were sensitive to human facial features under field conditions by comparing flight initiation distances and urgency of escape behavior to human approaches varying in eye contact and facial expression. We first examined whether crows distinguish between an approaching human who is directly gazing at them and a human approaching them with an averted gaze. In a second experiment, we tested whether crows differentiate a smiling from scowling human approaching them with direct or averted gaze. In the first experiment, we found that crows fled sooner and more urgently when humans were directly gazing at them. Similarly, in the second experiment, crows responded sooner to a direct vs. averted gaze; however, they did not react differently to varying human facial expressions. We suggest that crows use human gaze as a reliable visual cue compared with facial expressions when making decisions about responding to approaching humans. This is the first study to show that a wild corvid species changes its behavior based on human gaze, possibly representing an adaptation to living in human-dominated urban areas and suggesting crows might perceive human intention by this visual cue.