The Story of the Dodo

By Julian Hume

The Dodo

The dodo, Raphus cucullatus (family Columbidae), has become one of the most famous birds in the world, a true icon of extinction, with probably more written about it than any other bird, yet we know practically nothing about it in life. It was endemic to the volcanic and isolated Mascarene island of Mauritius, which is situated in the southwestern Indian Ocean around 829 km east of Madagascar, the nearest large land mass. Arab traders probably discovered the Mascarene Islands as early as the 13th century, followed by the Portuguese in the early 16th century, but neither the Arabs nor Portuguese, as far as it is known, settled there. Following the acquisition of Mauritius by the Dutch in 1598, the islands were used as ports of call for provisioning ships for the next century, and vague and inadequate references to the original fauna and flora, including the dodo, were recorded in ships’ logs and journals. These early accounts are invaluable in determining the island’s original ecological composition, because by the end of the 17th century, Mauritius had been altered beyond recognition due to the ravages of humans and their commensal animals. It was during this first hundred years of human occupation on Mauritius that the dodo became extinct.

dodo-extinct-dung-beetles-plus-other-extinct-invertebrates

Dodo, extinct dung beetles and other extinct invertebrates, painting by Julian Hume

Written and pictorial evidence

Ships’ logs and journals became important source material for artists and book publishers, and it was these publications, often expanded and illustrated long after the voyage itself, that have become the source material for scientific study. But these accounts and illustrations are often plagiarized from earlier sources, contradictory, or simply manufactured from pure imagination, and has resulted in a wealth of scientific myths and misconceptions about the dodo itself.

Transportation of dodo specimens, living or dead

It has been postulated by some authorities that each image of a dodo represents a different individual and as a result at least 17 dodos must have been transported to Europe and the Far East. However, physical and documentary evidence suggests that as few as two or three dodos made the journey alive to Europe, and a similar number survived the journey east, as far as Japan. One specimen, the only dodo to have unequivocally reached Europe alive, was exhibited in a shop somewhere in London in 1638. This individual may have been the one that ended up in the Ashmolean Museum (now University Museum), Oxford. Despite popular belief, this unique stuffed specimen was not thrown onto a fire to be burned. In 1755, after examining the then disintegrating specimen, the trustees could save only the head and one foot, disposing of the rest. The head, which still retains soft tissue, and the bony core of the foot still reside in Oxford today, whereas all other dodo soft tissue remnants have long since decayed or have been lost.

Extinction

Inferences made from the few accounts of dodos on Mauritius indicate that the birds disappeared on the mainland concomitant with ever-increasing encroachment by humans and their commensal animals. Hunting was probably restricted to the coastal areas and extremely limited because of the small human population; therefore, it was almost certainly competition and predation by introduced animals, such as rats, monkeys, pigs, goats, and deer, that were responsible for the dodo’s demise. Although still a matter of debate, dodos may have survived until at least c.1690, but they had probably ceased to breed long before, with the last aged survivors hanging on in just a few remote places.

Race to find the first fossil evidence

Until the discovery of dodo bones in 1865, virtually no physical remains survived, leading some authorities to doubt that the dodo had ever existed. However, the head and foot at Oxford and a foot in London formed the basis for the first anatomical study by Hugh Strickland and Alexander Melville in 1848, after which scientific interest in procuring dodo specimens intensified, in particular, the need to discover fossil material on Mauritius.

The publication of Lewis Carroll’s ‘Alice’s Adventures in Wonderland’ in 1865 gave worldwide recognition to the Dodo and it coincided with the discovery of subfossil dodo bones in the same year at the Mare aux Songes marsh in Mauritius. George Clark, Master of the Diocesan School at Mahébourg, Mauritius and Harry Higginson, a railway engineer, co-discovered the site, and Clark began excavations using local labourers. News of the discovery reached Professor Richard Owen, then superintendent at the British Museum of Natural History, and also Alfred Newton, who was based at Cambridge, England. Both Owen and Newton were on friendly terms and Owen was intending to give his full testimonial support to Alfred’s application to become the first professor at the University of Zoology and Comparative Anatomy in Cambridge. Clark sent the first consignment of bones to Owen in September 1865, and organized another shipment of bones for Newton, who was intending to sell them by auction the following year. Owen was tipped-off about the consignment by Captain Frederick-James Mylius, George Clark’s son-in-law, and Owen intercepted the bones. He arranged a new deal with Clark via Mylius and promptly retained all of the material, including further shipments. Clark received £100 from Owen for exactly 100 Dodo bones, which was an extremely large reward at the time. Alfred was obviously furious and was going to make a formal complaint to the Royal Society, but Owen blatantly blackmailed Alfred from taking any further action by threatening his application to become professor at Cambridge. Alfred had to relinquish his claim on the dodo and also had to withdraw a manuscript describing the dodo’s anatomy.

Owen’s ruthless tactics paid off, as it resulted in the publication of his monograph on the dodo in October 1866, in which he formerly described the dodo’s anatomy.

The Mare aux Songes marsh was reworked more intensively in 1893 by Theodore Sauzier and again by Paul Carié in the early 1900s, resulting in the retrieval of many more dodo bones. Such was the abundance of dodo material collected from the marsh—albeit a composite of many different individuals—that almost all dodo remains held in museum collections today are derived from this one site. Around the turn of the 20th century, Louis Etienne Thirioux, a hairdresser by trade, discovered a complete dodo in a valley beneath Le Pouce Mountain, and remains the most complete and only associated dodo in existence.

Affinities

The affinities of the dodo were explored by numerous authors, and it was often preposterously placed within a large assortment of bird orders—for example, a miniature ostrich, a rail, or even a vulture. After examining a skull in Copenhagen, Professor J. T. Reinhardt proposed that the dodo was related to Columbiformes (pigeons and doves). This assertion was initially met with ridicule, but after Strickland and Melville confirmed his theory by examination of the Oxford dodo head, the idea became universally accepted. DNA studies have now concluded that the dodo and closely related solitaire Pezophaps solitaria of Rodrigues are a sister clade nested within the family Columbidae and derived from the same ancestor as the Southeast Asian Nicobar pigeon Caleonas nicobarica.

mare-aux-songes-4000-ybp

Mare aux songes 4,000 YBP, painting by Julian Hume

Recent discoveries

In 2005, a Dutch expedition discovered fresh fossil material at the Mare aux Songes. This resulted in a full scale excavations from 2006 to 2010, and revealed that thousands of bones still existed at the site. The fossil layer also contained seeds, tree trunks and branches, leaves, insects, land snails, and even fungi, deposited long before humans arrived on the island. The fossil remains are dominated by extinct giant tortoises Cylindraspis sp., but they also include snakes, lizards, owls, hawks, rails, parrots, pigeons, and songbirds. The flora comprised various palms, screw pines Pandanus sp., canopy trees such as the dodo tree (tambalacoque) Sideroxylon grandiflorum and ebony Diospyros sp., and a host of smaller plant species, enabling scientists to reconstruct the dodo’s habitat in a pristine state. In 2007, a complete but degraded dodo skeleton, ‘Dodo Fred’, was discovered in a cave in the highlands, with further fossil discoveries made in lowland caves, which increased the known distribution of the dodo on Mauritius.

As a result of this new physical evidence, it is now possible to make scientifically valid conclusions about the dodo’s ecology and the ecosystem in which it lived. The dodo was found close to the coast as well as in the mountains, occupying dry and wet forest zones, and with its well-developed olfactory system, fed on fallen fruits and perhaps invertebrates by locating them with a sense of smell. Judging by the number of individuals preserved, it was abundant in the lowlands at least, and was well adapted to survive the sometimes harsh conditions of the seasonal variations in food supply. Now extinct specialist bird dung beetles utilised the dodo’s waste products, and trees and shrubs relied on it as a dispersal agent for their nuts and seeds.

However, the dodo still remains somewhat of a mystery. For example, what was the use of its large, hooked bill and what role did this giant flightless pigeon play in its forest home? What is certain is that the dodo was unable to cope with the rapid changes brought about by anthropogenic agencies and died out less than a century after being discovered.

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