Dodo
2007 Schools Wikipedia Selection. Related subjects: Birds
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Extinct (1681)
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Raphus cucullatus Linnaeus, 1758 |
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Former range (in red)
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The Mauritius Dodo (Raphus cucullatus, called Didus ineptus by Linnaeus), more commonly just dodo, was a metre-high (three-foot) flightless bird of the island of Mauritius. The dodo, which is now extinct, lived on fruit and nested on the ground.
Dodo biology
Taxonomy and evolution
The dodo is a close relative of modern pigeons and doves. DNA sequence analysis suggests that the dodo's ancestors diverged from those of its closest known relative, the Rodriguez Solitaire (which is also extinct), about 25 million years ago, in the deserts of the middle east; these birds reached their impressive size as a result of the subsequent isolation of their desert homes in accordance with Foster's rule. The same study suggested that the Southeast Asian Nicobar Pigeon is the closest living relative of the dodo and the Rodriguez Solitaire. However, the proposed phylogeny is questionable as regards the relationships of other taxa and must be considered less than reliable pending further research; all that can be said with certainty is that the ancestors of the didine birds were pigeons from Southeast Asia, which agrees with the origin of most of the Sahara's birds. Whether the dodo and Rodriguez Solitaire were actually closest to the Nicobar Pigeon among the living birds or whether they are closer to other groups of the same radiation such as Ducula, Treron or Goura pigeons, the proposed relationship to the Nicobar Pigeon being an artifact of long branch attraction, is not clear at the moment.
Morphology and flight
In October 2005, an important site of dodo remains was found by Dutch researchers in Mauritius, including birds of various stages of maturity. These findings were made public in December 2005 in the Naturalis in Leiden. Before this find, few dodo specimens were known. Dublin's Natural History Museum had an assembled specimen, while the most intact remains from a single bird are a skeletal foot and a head, which contains the only known soft tissue remains of the species.
The decaying remnants of the last complete stuffed dodo, in Oxford's Ashmolean Museum, was ordered to be burned by the museum's director in 1755; the foot and head were salvaged from this specimen, and are currently on display. Nevertheless, from artists' renditions we know that the Dodo had blue-grey plumage, a 23-centimetre (9-inch) blackish hooked bill with a reddish point, very small wings, stout yellow legs, and a tuft of curly feathers high on its rear end. Dodos were very large birds, weighing about 23 kg (50 pounds). The breast structure was insufficient to have ever supported flight. These ground-bound birds evolved to take advantage of an island ecology with no predators.
The traditional image of the dodo is of a fat, clumsy bird, but this view has been challenged by Andrew Kitchener, a biologist at the Royal Museum of Scotland (reported in National Geographic News, February 2002), who believes that the old drawings showed overfed captive specimens. As Mauritius has marked dry and wet seasons, the dodo probably fattened itself on ripe fruits at the end of the wet season to live through the dry season where food was scarce; contemporary reports speak of the birds' "greedy" appetite. Thus, in captivity with food readily available, the birds would become overfed very easily. It had lived for thousands of years on Mauritius without any predators, being the largest animal then on the island (Mauritius had no native inhabitants).
Diet
The Tambalacoque, also known as the Dodo tree, was hypothesized by Stanley Temple to have been eaten from by Dodos, and only by passing through the digestive tract of the Dodo could the seeds germinate. Temple (1977) force-fed seventeen tambalacoque fruits to Wild Turkeys and three germinated. Temple did not try to germinate any seeds from control fruits not fed to turkeys so the effect of feeding fruits to turkeys was unclear. Temple also overlooked reports on tambalacoque seed germination by Hill (1941) and King (1946), who found the seeds germinated without abrading.
Dodos and humans
Etymology
The etymology of the word dodo is unclear. It may be related to dodaars, the Dutch name of the little Grebe or Dabchick. The connection may have been made because of similar feathers of the hind end or because both animals were ungainly. However, the Dutch are also known to have called the bird the "walgvogel" ("loathsome bird") in reference to its taste. This last name was used for the first time in the journal of vice-admiral Wybrand van Warwijck who visited and named the island Mauritius in 1598. Dodo or Dodaerse is recorded in captain Wilhem Van Westzanen's journal four years later, but it is unclear whether he was the first one to use this name. Before the Dutch the Portuguese had already visited the island. According to Encarta Dictionary and Chambers Dictionary of Etymology, 'dodo' comes from Portuguese doudo (currently, more often, doido) meaning 'fool' or 'crazy'. However, the present Portuguese name for the bird dodô ("dodo") is of English origin. The Portuguese word doudo or doido may itself be a loanword from Old English (cp. English 'dolt'). Yet another possibility, as author David Quammen has noted in his book Song of the Dodo, "that 'dodo' was an onomatopoeic approximation of the bird's own call, a two-note pigeony sound like 'doo-doo'."
Dodos and culture
The Dodo rampant appears on the Coat of arms of Mauritius. The Dodo is the symbol of the Brasseries de Bourbon, a popular brewer on Réunion Island. The Dodo is the symbol and mascot of the Durrell Wildlife Conservation Trust and the Jersey Zoological Park, founded by Gerald Durrell. The Dodo's significance as one of the best-known extinct animals and its singular appearance has led to its use in literature and popular culture to symbolize a concept or object that will or has become out of date, expressed in the expression "dead as a dodo". It is also used by environmental organizations that promote the protection of endangered species. Recently, the Dodo is set as an example of the documentary Flock of Dodos highlighting the "evolution intelligent-design circus".
Extinction
The cause of the dodo's extinction is not certain, but recent evidence suggests that it was nearly wiped out by some natural disaster before humans arrived on the island, its population reduced so severely that it fell below sustainable levels.
As with many animals evolving in isolation from significant predators, the Dodo was entirely fearless of people, and this, in combination with its flightlessness, made it easy prey. (The island was first visited by the Portuguese in 1507, but the Dutch were the first permanent settlers on the island.) However, when humans first arrived on Mauritius, they also brought with them other animals that had not existed on the island before, including sheep, dogs, pigs, cats, rats and monkeys, which plundered the Dodo nests, while humans destroyed the forests where they made their homes.
There is some controversy surrounding the extinction date of the Dodo. David Roberts states that "the extinction of the Dodo is commonly dated to the last confirmed sighting in 1662, reported by shipwrecked mariner Volkert Evertsz", but other sources suggest 1681.
Roberts points out that because the sighting prior to 1662 was in 1638, the Dodo was likely already very rare by the 1660s. However, statistical analysis of the hunting records of Isaac Joan Lamotius, carried out by Julian Hume and coworkers, gives a new estimated extinction date of 1693, with a 95% confidence interval of 1688 to 1715.
The last known Dodo was killed less than 100 years after the species' discovery, and no complete specimens are preserved, although a number of museum collections contain Dodo skeletons. The most complete of these on display in the Oxford Natural History museum, England. A Dodo egg is on display at the East London museum in South Africa. Genetic material has been recovered from these and its analysis has confirmed that the Dodo was a close relative of pigeon species that are to be found in Africa and especially South Asia.
Few took particular notice of the extinct bird until it became featured as a character in Lewis Carroll's Alice's Adventures in Wonderland (1865). With the popularity of the book, the Dodo became a household word: "as dead as a Dodo".