All post-1638 depictions appear to be based on earlier images, around the time reports mentioning dodos became rarer. Differences in the depictions led ornithologists such as Anthonie Cornelis Oudemans and Masauji Hachisuka to speculate about sexual dimorphism, ontogenic traits, seasonal variation, and even the existence of different species, but these theories are not accepted today. Because details such as markings of the beak, the form of the tail feathers, and colouration vary from account to account, it is impossible to determine the exact morphology of these features, whether they signal age or sex, or if they even reflect reality. Hume argued that the nostrils of the living dodo would have been slits, as seen in the Gelderland, Cornelis Saftleven, Savery's Crocker Art Gallery, and Mansur images. According to this claim, the gaping nostrils often seen in paintings indicate that taxidermy specimens were used as models. Most depictions show that the wings were held in an extended position, unlike flighted pigeons, but similar to ratites such as the ostrich and kiwi.
All post-1638 depictions appear to be based on earlier images, around the time reports mentioning dodos became rarer. Differences in the depictions led ornithologists such as Anthonie Cornelis Oudemans and Masauji Hachisuka to speculate about sexual dimorphism, ontogenic traits, seasonal variation, and even the existence of different species but these theories are not accepted today. Because details such as markings of the beak, the form of the tail feathers, and colouration vary from account to account it is impossible to determine the exact morphology of these features, whether they signal age or sex, or if they even reflect reality. Hume argued that the nostrils of the living dodo would have been slits, as seen in the Gelderland, Cornelis Saftleven, Savery's Crocker Art Gallery, and Mansur images. According to this claim, the gaping nostrils often seen in paintings indicate that taxidermy specimens were used as models. Most depictions show that the wings were held in an extended position, unlike flighted pigeons, but similar to ratites such as the ostrich and kiwi.