2017 Advent Calendar / Advent calendar

Door 22 – Sticking with turkey

Sticking with turkey – the life and death of the dodo

Dodo, Natural History Museum London (c. John Cummings)

The dodo, Raphus cucullatus, is possibly the most famous animal to have gone extinct in modern times but, confusingly, it is also one of the extinct animals that we know the least about. Very few written accounts of living examples exist, the validity of artistic depictions are questionable and only one specimen with soft tissue remains, now held at the Oxford Natural History Museum. Indeed, the total human knowledge of the dodo could be summarised in a single blog post, or several theses.

The dodo is endemic to the Mascarene island of Mauritius in the Indian Ocean. The Mascarenes were visited by Arab traders in the early 13th century and Portuguese explorers in the early 16th century but no documented accounts of Mauritian island fauna existed until the Dutch arrival and settlement in 1598.

Relief map of Mauritius

Mauritius is a richly vegetated island with an abundance of seed, fruit and other plant matter. Artistic representations of the dodo often place the bird in a waterside setting but these must be assessed with caution. Many of the artworks were produced by Roelant Savery, a Flanders born painter, who is known to have never travelled to Mauritius himself. It has been suggested that the Dutch colonists brought a live dodo to the Netherlands from which Savery painted his pieces so it is possible that Savery used a live model but that the setting and other included creatures are an artistic creation.

The dodo’s diet is a point of much speculation. There is only one contemporary account that simply states: “their food was raw fruit” (anon, 1631), suggesting that the dodo ate fallen seeds and fruit. It is certainly true that dodos would have been ground-feeders and the vegetation on Mauritius would have provided an abundance of seeds and fruit all year round.

The species had previously been grouped with birds that are closer to the dodo in terms of how they look, such as the ratites (large flightless birds such as ostriches), and the raptors (birds of prey). However DNA evidence has now placed dodos within the family Columbidae: pigeons and doves.

Nicobar Pigeon Bird Pigeon Wildlife Nest Exotic

Much of what we know about dodos comes from comparison with closely related living columbids. The closest living relative to the dodo is the Nicobar pigeon which lives in the Indian owned Adaman and Nicobar islands in the Indian Ocean. Based on the shape of the beak, comparisons suggest that the dodo may have consumed hard food items such as seeds and shelly invertebrates, as depicted in Roelant Savery’s painting. Furthermore, the strong feet, claws and hooked beak of the dodo would have made it capable of breaking into mollusc shells and able to retrieve eggs and extract the inside. The dodo may also have made use of gastroliths, small rocks that are swallowed by animals to help grind down food, making it easier to digest. Nicobar pigeons use gastroliths in their feeding habits and there are other accounts that describe the presence of gastroliths within dodo gizzards.

The famous Edwards’s Dodo, painted by Savery in 1626

So what of their extinction? The story known by most is that the flightless birds were as delicious as they were easy to catch and were quickly caught by Dutch settlers, hungry after a long period at sea. They were, in fact, so tasty that they were hunted to extinction within a century of Dutch settlement.

But is this common conception true? Well, one account as to the delicacy of the dodo was made by Sir Thomas Herbert, an English 1st Baronet under King Charles I, who described the meat of the dodo as follows: “through its oyliness it cannot chuse but quickly cloy and nauseate the stomach, being indeed more pleasurable to look than feed upon”. Given this, and other, similar accounts, it is likely that hunting by humans was a negligible factor in the extinction of the dodo. Instead, the main cause of extinction was probably the introduction of invasive species to their habitat. Animals like black rats, pigs and crab-eating macaques would have predated on eggs and young dodos, disrupting nesting and breeding – a problem that is still pervasive in many island ecologies.

So, given its ‘oyliness’, may we suggest that our readers stick to the turkey, or vegetarian options, this Christmas and leave the dodo in Oxford. Enjoy the brussels!

Will Foreman and Lucy Roberts

3 thoughts on “Door 22 – Sticking with turkey

  1. Pingback: Door 24 – Quiz answers, challenge winners and a very merry Christmas! | Geological Society of London blog

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