Fiona Jones


For me, the dodo (Raphus cucullatus) is as intimately associated with the city of Oxford as the dreaming spires, or an afternoon spent punting on the Cherwell. Its plump form famously decorates the pages of Alice’s Adventures in Wonderland1 – Lewis Carroll’s 1865 novel, which in itself has become an Oxford treasure. However, the dodo’s relationship with Oxford began long before Carroll put pen to paper, when, on the 20th March 1683, a taxidermied specimen was put on display at the Ashmolean Museum2. The mummified head and foot are now all that remain, and they can now be seen at the Oxford University Museum of Natural History3. The pride surrounding this specimen is clear, and the dodo is now the emblem of the museum. This is with good cause too, as the Oxford dodo represents the most complete individual we have3.

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The Oxford Dodo, on display at the Oxford University Museum of Natural History. Photo credit: Fiona Jones

But in addition to inspiring writers – and scientists – what is the relevance of the dodo to biology? Well, I think that exploration of the dodo story is a novel way of touching on multiple disciplines within the biological sciences, showing how knowledge from seemingly disparate fields may be required to fully understand a specimen.

What do I mean by this? Well firstly, we can examine the life history of this bird when it was…well…not as dead as a dodo. Specifically, the dodo can teach us about the complex nature of ecological interspecific interactions, highlighting that things may not be as they first appear. In a 1977 paper, Temple proposed that the seeds of the tambalacoque tree – endemic to the island of Mauritius (home to the dodo) – needed to pass through the gizzard of the dodo in order to successfully germinate4. He went so far as to suggest that the dodo and tambalacoque tree were involved in a coevolved obligate mutualism, based partly on the notion that no tambalacoque trees had germinated in the 300 years since the dodo’s extinction5. This hypothesis has since been refuted, with Witmer and Cheke (1991) pointing out that seeds with a thick coating are often able to “[rupture] along a natural zone of weakness”, and that there is little evidence to suggest that digestion by the dodo would have quickened the germination process5. They also question the idea that no tambalacoque seedlings have grown since the dodo’s extinction; indeed, Vaughan and Wiehe (1941) identified 33 trees in one hectare of forest, including three within the 10-14cm diameter at breast height (DBH) category5, 6. Surely these trees must have been less than ~260-270 years old?

On a different note, the dodo story is an example of the difficulties encountered when trying to understand the phylogenetic relationships (i.e. resolve the evolutionary family tree) of a species that has long been extinct. Indeed, it can be particularly challenging to do this for endemic island birds, which can be associated with unusual traits such as gigantism and flightlessness6. Confusion has surrounded this topic since the 1800s, and only with the aid of the Oxford dodo has it been possible to untangle its family history3, 7. It is now believed that its sister taxon was the solitaire (Pezophaps solitaria), with its closest living relative being the Nicobar pigeon (Caloenas nicobarica)7.

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Family resemblance? This is the Nicobar pigeon (Caloenas nicobarica), the closest living relative of the dodo. Image source: Wikipedia

The last example relates to what the dodo story can teach us about the public perception of a species. Earlier I referred to the dodo’s ‘plump form’, and the portrayal of the dodo by Carroll and others (notably Jan Savery and George Edwards, who painted the dodo in 1651 and 1759, respectively) have indeed lead us to believe that the dodo was – to put it bluntly – pretty fat, with a comical, eccentric beak3. So, was this not the case? If not, how can we possibly know what it looked like with limited evidence remaining? Some have suggested that the dodo was overfed while in captivity, causing it to become obese3, 8. In this situation, it is therefore necessary to hunt for early accounts of the dodo’s appearance, recorded by those who saw it in its natural habitat. Interestingly, a sketch from the first Dutch expedition to Mauritius in 1598 shows the dodo to be quite slim3. This supports calculations made using the Oxford dodo, and bones from the Natural History Museum and the Cambridge Zoology Museum, which suggest the dodo skeleton could not have supported an obese bird. As such, the Oxford dodo teaches us to be wary of interpreting what we see in books and paintings as scientific fact.

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The dodo, as painted by Jan Savery (1589-1654) in 1651. Image source: http://assets.atlasobscura.com/article_images/5133/image

Please see http://www.oum.ox.ac.uk/ for more information about the museum which the Oxford dodo calls home.

References

[1] Carroll, L. (1865). Alice’s Adventures in Wonderland. UK: Macmillan.
[2] Norton, C. (2013). The Last Dodo. History Today 63(4). Retrieved from http://www.historytoday.com/charles-norton/last-dodo on 25/11/15.
[3] OUMNH. Learning more…The Oxford Dodo. Retrieved from http://www.oum.ox.ac.uk/learning/pdfs/dodo.pdf on 24/11/15.
[4] Temple, S.A. (1977). Plant-animal mutualism: Coevolution with dodo leads to near extinction of plant. Science 197(4306) pp. 885-886.
[5] Witmer, M.C. & Cheke, A.S. (1991). The dodo and the tambalacoque tree: An obligate mutualism reconsidered. Nordic Society Oikos 61(1) pp. 133-137.
[6] Vaughan, R.E. & Wiehe, P.O. (1941) Studies on the vegetation of Mauritius. III. The structure and development of the upland climax forest. Journal of Ecology 29(1) pp. 127-160.
[7] Shapiro et al. (2002). Flight of the dodo. Science 295(5560) p. 1683.
[8] Connor, S. (2011). Driven to extinction: Who killed the Dodo? Retrieved from http://www.independent.co.uk/news/science/driven-to-extinction-who-killed-the-dodo-481631.html on 25/11/15.

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