Author’s note -Last week I was surprised to learn that this post was selected for the 2011 edition of The Open Laboratorythe 2011 edition of The Open Laboratory – a “best of” science blogs mixtape which features some of the top blog entries from the past year. Good to know that the dodo still has friends. I have a bit of editing and updating to do, but here’s the original essay which I published on February 10, 2011. The next time you see the post, it will be in dead tree form.
The Dodo, Didus, is a bird that inhabits some of the islands of the East Indies. Its history is little known; but if the representation of it be at all just, this is the ugliest and most disgusting of birds, resembling in its appearance one of those bloated and unwieldy persons who by a long course of vicious and gross indulgences are become a libel on the human figure. – Charlotte Turner Smith, A natural history of birds: intended chiefly for young persons, 1807
I hate to say it, but the dodo looked as if it deserved extinction. What other fate could there have been for such a foolish-looking ground pigeon? A grotesque, tubby creature with huge nostrils and a ridiculous little poof of tail feathers, Raphus cucullatus had the air of a bird that stood still with a blank stare as the scythe of extinction lopped off its head.
But the dodo I have always known is not a true reflection of the bird. Notes, skeletal scraps, a disregard for soft-tissue anatomy, and a bit of artistic license created this symbol of extinction. The dodo looked so stupid because we made it so.
In order to understand the legacy of the dodo, a little background on its demise is required. It has not been very long since we lost the dodo – only about three centuries – but the exact date has been difficult to pin down. Until recently, the last confirmed dodo sighting on its home island of Mauritius was made in 1662, but a 2003 estimate by David Roberts and Andrew Solow placed the extinction of the bird around 1690. They were probably not far off.
Historical documents described by Julian Hume, David Martill, and Christopher Dewdney in 2004 confirmed that dodos were killed for the Opperhoofd (governor) of Mauritius, Hubert Hugo, on August 16, 1673. Hugo’s successor, Isaac Joan Lamotius, also jotted down notes about still-living dodos in his notebooks at least twelve times between 1685 and 1688, with the last capture of a dodo recorded on November 25, 1688. (There is some doubt here, as some historians think Lamotius was referring to the also-extinct red rail, but Hume and co-authors pointed out that Lamotius was a skilled observer of nature who was unlikely to confuse this distinctive dodo with the red rail.) Using these late sightings with the estimation techniques of Roberts and Solow, the scientists came up with a new extinction date of 1693, although we will probably never know when the last dodo actually died. Over a century before the idea of extinction was accepted, those who extirpated the dodo did not keep detailed records of the bird’s decline. That an entire species could disappear simply did not occur to them.
No single cause drove the dodo into extinction. Humans hunted the naive birds, of course, but the rats, cats, pigs, and other animals that we brought along with us were just as destructive. The extinction of the dodo was not simply a matter of systematic extermination. Our species created a major ecological disruption that many unique island species could nope cope with. Still, the fact that dodos were regularly hunted greatly contributed to their demise, and, contrary to the common belief that they had a disgusting flavor, Jan Den Hengst has drawn on several historical sources to show that dodo meat was considered quite palatable by sailors. Who knows how many dodos were killed to satisfy gustatory curiosity?
Thankfully for us – though not for the dodo – some of those hungry sailors recorded a few aspects of the bird’s natural history. The Dutch who stayed on Mauritius observed the dodos, made notes about them, sketched them, and even brought stuffed dodos back to Europe, so why, then, are there so many inaccurate restorations? We’re not dealing with some animal that became extinct during the Pleistocene, living on only in sketches drafted on cave walls. The Age of Exploration both discovered and wiped out the dodo – from a geological perspective, it popped out of existence only yesterday – and so it is puzzling why an animal that died out so recently has been so poorly represented.
In many cases, mistakes about the dodo are copycat errors. One artist got something wrong and the mistake stuck. Take the color of the dodos, for example. First-hand accounts of the birds agreed that they sported plumage that was black to grey in color, but many 17th century Dutch paintings restored them as white. Why they did so is unknown – perhaps artists mistakenly gave the dodos the color of another now-extinct bird, the white ibis of Réunion Island, or perhaps the unique coloring of an albino dodo caused it to be copied more regularly than others. Whatever the reason, light-colored dodos stuck around.
A single painting by Roelandt Savery had an even stronger effect. His rendition of the dodo, created around 1626, differed from earlier drawings of dodos as long-legged and spry in showing the dodo as a fat, stumpy bird. Although earlier illustrations of live dodos had been made by travelers to Mauritius, Savery’s was by for the most ornate, stylized, and detailed painting, so it is not surprising that subsequent artists followed his lead. Even Richard Owen, the brilliant Victorian anatomist, later used Savery’s rendition as a starting point for reconstructing the bird.
We can’t be too critical of Savery, though. There are only two confirmed accounts of live dodos that were displayed in Europe, and Savery probably never saw a still-breathing dodo. Most artists who illustrated the bird had not seen a living specimen. This situation left at least one tell-tale sign in artistic renderings of the bird – the enlarged nostrils. Sketches of live and recently-deceased birds show the nostrils as being very small, but in skeletons and stuffed specimens the soft tissue was gone, leaving the nasal cavity open and looking relatively large. If a dodo restoration has large gaping nostrils, then it was based upon a long-dead specimen.
Mistakes about dodo anatomy gained a cultural inertia that was difficult to stop. Extensively reviewed by dodo-expert Julian Hume in 2006, illustrations of dodos were based on scrappy remnants and the works of others. “The Dodo, one of the most documented and famous of birds and a leading contender as the ‘icon’ of extinction,” he wrote, “has endured more than its fare share of over zealous misinterpretation.” At least the Pleistocene artists who drew mammoths, rhinos, and Irish elk on cave walls had seen the living creatures; in the case of the more recently-extinct dodo, the distance between the artists and last birds allowed errors to take hold and quickly proliferate.
Strangely, though, the dodo became an almost mythical creature as soon as it became extinct. Samuel Turvey and Anthony Cheke have documented that, despite the bird’s notoriety among the Dutch, many French naturalists considered the bird to be entirely fanciful. To some 18th century naturalists, the dodo was about as real as a griffin, and there seemed to be no conclusive evidence that the bird had ever actually existed. Given that the French took control of Mauritius in 1710 and found no sign of the dodos, it seemed possible that the birds were the product of exaggeration and overactive imaginations.
It was only in the early 19th century, when European naturalists began describing dodo scraps scattered among various museums, that it became widely recognized as a real animal that had recently gone extinct at the hands of our species. (And, of course, its appearance as an icon of political foolishness in Alice’s Adventures in Wonderland helped.) “[B]oth chance and necessity played a part in the Dodo’s rise to fame,” Turvey and Cheke noted, and the dodo only became symbol of extinction when the disappearance of other creatures – such as that of the Great Auk in the mid-19th century – affirmed that species truly could undergo a catastrophic decline. Scientists working today know more about the dodo than the naturalists who overlapped in time with the last birds, although much about this strange bird remains uncertain.
Among the frustratingly fuzzy questions about the dodo was how much it weighed. Here the notes of eyewitnesses and estimates made by scientists conflict. Whereas some mariners said that dodos weighed as much as 50 pounds, scientific estimates based upon the bird’s skeletal anatomy have restored them between 23 and 46 pounds. The higher estimate is consistent with the pudgy, waddling creature seen in seventeenth century paintings, whereas the lower bar fit the earlier reports of svelt, long-legged dodos. According to a paper just published by Delphine Angst, Eric Buffetaut, Anick Abourachid that used leg bones – from femur to ankle – to estimate the mass of the bird, dodos may have come in at just under the previous lower limit. Dodos only weighed about 22 pounds. This is about as heavy as a wild turkey, and the scientists proposed that the heavier estimates of the 17th century mariners may have been inspired by the puffed-up appearance of some birds and a bit of exaggeration.
In order to truly understand the dodo, though, we need more remains of the bird. Despite the number of preserved dodos brought back to Europe, scientists have rarely had the opportunity to study whole skeletons. The scant sampling of dodo remains collected during the 17th century were lost, destroyed, and crumbled to dust. In a famous bit of historical lore, by 1755 the last remaining stuffed dodo in Oxford’s Ashmolean Museum had degraded to such a point that it was ordered to be destroyed in a fire and it was only through the quick intervention of a sharp-eyed naturalist that the head and foot were saved from the flames. As with many cherished stories, though, this is untrue. The dodo was so badly decayed that the museum’s curator had the head and foot removed so that they might be saved from the otherwise rotted mount.
The first scientific assessment of a complete dodo skeleton was made in 1866 by Richard Owen. He had reconstructed the skeleton of the dodo from the sub-fossil remains of multiple individual birds found on Mauritius, although Owen’s vision was controversial for two different reasons. From an anatomical perspective, Owen had assumed that Savery based his painting off a living bird and simply reconstructed the bones to fit within an outline of the artist’s plump dodo. (Owen later issued an updated, more upright version of the dodo skeleton in 1872.) Owen’s ability to reconstruct the bird at all, though, was made possible by his hijacking of fossils intended for naturalist Alfred Newton at Cambridge. Owen’s stake on the dodo forced Newton to reluctantly bare his throat by offering Owen the best of the dodo fossils he had in his possession and also withdrawing his own paper on the dodo from potential publication, letting Owen become the prime interpreter of yet another fantastic extinct creature.
Lacking any stuffed specimens or new skeletons, it is easy to see how the traditional image of the buffonish dodo remained entrenched, but recent expeditions to Mauritius have turned up new fossils of the bird. A 2007 report stated that the most complete dodo skeleton ever found has been recovered from a cave deposit, and a 2009 paper by Kenneth Rijsdijk, Julian Hume, and colleagues described a 4,000 year old bonebed rich in dodo remains. This site has allowed a fleeting glimpse into what Mauritius was like long before the arrival of the Dutch sailors. In addition to numerous dodo remains, the bones of extinct giant tortoises, bats, and other birds were found in the same deposits, which have been reconstructed as a freshwater oasis in an otherwise dry habitat. The accumulation was not the result of one catastrophic event, but had built up over several centuries as seasonal droughts killed animals that relied on this watersource. But this is just one brief snapshot in the history of the dodo. How far back its history goes – and how the bird evolved in the first place – is a mystery.
Despite its proximity to us in time, it is almost easier to think of the dodo as a fossil creature. So much of what we thought we knew about it relied on the testimony of long-dead witnesses. Only by going back to the bones of the dodo can we start to understand this bird’s biology. The dodo is an unmistakable icon of extinction, a species squandered in near-time, but separating the animal from its modern mythology is an ongoing task.
Top Image: The dodo as painted by Roelant Savery around 1626. Image from Wikipedia.
Angst, D., Buffetaut, E., & Abourachid, A. (2011). The end of the fat dodo? A new mass estimate for Raphus cucullatus Naturwissenschaften DOI: 10.1007/s00114-010-0759-7
DEN HENGST, J. (2009). The dodo and scientific fantasies: durable myths of a tough bird Archives of Natural History, 36 (1), 136-145 DOI: 10.3366/E0260954108000697
Hume, J. (2006). The history of the Dodo Raphus cucullatus and the penguin of Mauritius Historical Biology, 18 (2), 65-89 DOI: 10.1080/08912960600639400
Hume, Julian; Datta, Ann; Martill, David M. (2006). Unpublished drawings of the Dodo Raphus cucullatus and notes on Dodo skin relics Bulletin of the British Ornithologists’ Club, 126 (A)
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