Gaze Following in Pigeons Increases with the Number of Demonstrators

Abstract

Gaze following, orienting ones gaze in the same direction as another individual, is widespread across species and well-studied in terms of cognitive mechanisms. However, the role of collective context on this behavior is less understood. This study tested whether the number of conspecifics looking in a particular direction facilitates gaze following in pigeons (Columba livia). We presented attention-getting stimuli to subsets of pigeons (demonstrators), while other pigeons (observers) could not see the stimuli directly. We used a motion-capture system to track fine-scale movements of head and body orientations. Observer pigeons followed the gaze of demonstrators, specifically toward the target object rather than a perceptually similar distractor. Critically, the likelihood and frequency of gaze following increased with the number of demonstrators looking at the target. We observed no nonlinear effects, such as saturation or quorum thresholds, in this increasing trend, at least under our experimental conditions. In group-living species like pigeons, multiple individuals looking in the same direction may serve as a more reliable social signal. To our knowledge, this is the first study to demonstrate that the number of demonstrators influences gaze following in non- human animals, highlighting the critical role of collective context in animal social cognition.