Impact of visual stimuli on emotional reactivity in European starling Sturnus vulgaris

International audienceIt is generally admitted that birds are particularly sensitive to some biologically relevant visual stimuli. Thus, “eyes” or “raptor” 2D pictures are predominant in studies aiming to test repellent signals. But the question is how such representations are really perceived by birds and whether they all elicit the same type of potential avoidance. In this study, we tested the hypothesis that reactions to supposed “repellent“visual stimuli may depend on context and type of stimulus.Captive wild caught European starlings were exposed to a variety of repellent visual stimuli presented on a LCD monitor: human, eyes, snake, raptor, as well as neutral stimuli. Starlings expressed approaches and avoidances as well as gazes towards the screen. Their behavioural profiles revealed that they classified these stimuli into two categories, one grouping humans and eyes representations, the other raptors, snakes and neutral images. The approach of the images by birds reveals that the “universal” supposed effect of some predator like stimuli may be questioned in non appropriate contexts such as cages. The classification of the stimuli by the birds shows nevertheless that they do perceive the 2D images but it is more the internal representation of the stimulus that may be involved. The effect of experience has been further tested by using hand raised starlings.The significance of these results both in terms of cognitive abilities of birds and experimental set ups will be discussed