The Enchanted Gaze: Modification of Butterfly Eyespots in Flemish Art

As shown by Palaeolithic cave paintings, animals were the first subjects that humans began to depict and recall in their imagination, not solely for their utilitarian function. Some animals, due to distinctive morphological features, appear to have captured our ancestors’ attention in a special way. This is the case of animals with eye-like patterns, which have been reproduced in multiple ways and contexts throughout human history. This paper examines how Flemish artists have depicted a particular example of eye-like patterns, the eyespots on the wings of Aglais io butterflies, to understand whether these artists attributed any particular relevance to the eyespots. Modifications were identified by comparing 51 real images and 50 depicted ones of A. io by means of geometric morphometrics using 34 landmarks and 12 semi-landmarks. Generally, eyespots resulted to be located towards the interior of the wing, enabling us to discriminate 92% of depicted A. io from real images. This tendency is in line with the observer centre bias but, in this case, applied to the production of pictorial images rather than to their visual fruition, and which might be called ‘a shifting location bias’. Moreover, the eyespots’ size was depicted with accuracy and minimal variation among painters, while the outline of the wings appeared to be subject to considerable artistic freedom. Overall, these findings highlight the importance attributed by the artists to the eyespots, sustaining the hypothesis concerning the salience of this feature in attracting human attention.