The sensory world of the Dodo and Solitaire revealed by endocast and skull anatomy

The Dodo (Raphus cucullatus) and its close relative, the Rodriguez Solitaire (Pezophaps solitaria), are two of the most recognized symbols of human-caused extinction. Yet, despite their prominence in the scientific and popular literature, little is known about their behaviour. Because sensory systems shape how species perceive and interact with their environments and each other, estimating the sensory abilities of extinct taxa can provide insights into their behaviour and ecology. Here, we use a quantitative approach to compare the anatomy of cranial and endocranial features of the Dodo and Solitaire with 36 species of extant pigeons and doves (Columbiformes). The skull morphology of both the Dodo and Solitaire strikingly differs from other columbiforms, suggesting potential behavioural or ecological differences. The Solitaire’s sensory niche appears largely consistent with that of extant pigeons, whereas the Dodo departs more markedly from the typical columbiform condition. In particular, the Dodo exhibits potentially enhanced olfactory abilities and differences in visual processing abilities that might reflect shifts from an exclusively diurnal activity pattern. These results highlight the importance of a quantitative approach in the study of endocasts and skulls of extinct species and provide new insights into the behaviour of these two enigmatic species.