Sideroxylon grandiflorum, also known as the tambalacoque or dodo tree, is a long-lived species of tree in the sapote family Sapotaceae. It is endemic to Mauritius.
Description
The fruit of
Sideroxylon grandiflorum is analogous to a
peach. Each is termed a
drupe because each has a hard
endocarp, or pit, surrounding the seed. The plant itself superficially resembles the unrelated
Plumeria, but the dodo tree's flowers and fruit are
cauliflorous.
Ecology
In 1973, it was argued that the species was becoming
Extinction. There were supposedly only 13 specimens left, all estimated to be about 300 years old; the true age could not be determined because tambalacoque has no
.
Stanley Temple hypothesized that the
dodo, which became extinct in the 17th century, ate tambalacoque fruits, and that only after passing through the digestive tract of the dodo could the seeds germinate. Temple force-fed seventeen tambalacoque fruits to
in 1977. Seven of the fruits were crushed by the bird's gizzard, while the remaining ten were either regurgitated or passed with the bird's feces. Temple planted the remaining ten fruits, three of which germinated. Temple did not try to germinate any seeds from control fruits that had not been fed to turkeys so the effect on germination of feeding fruits to turkeys was unknown. Studies on tambalacoque seed germination by Hill (1941) and King (1946) found that the seeds germinated without abrading.
Temple's hypothesis that the tree required the dodo was contested. Others have suggested that the decline of the tree was exaggerated or that other extinct animals, such as Cylindraspis, , or the broad-billed parrot, may also have been distributing the seeds. The decline of the tree may be due to introduction of and crab-eating macaques, and competition from introduced plants. Alternatively, the difference in reported tree numbers may arise from the fact that young trees are not distinct in appearance and may easily be confused with similar species. Catling (2001) in a summary cites Owadally and Temple (1979) and Witmer (1991), while Hershey (2004) reviewed the flaws in Temple's dodo-tambalacoque hypothesis.
In 2004, the Botanical Society of America's Plant Science Bulletin disputed Temple's research as flawed. The Bulletin published evidence as to why the dodo's extinction did not directly cause the increasing disappearance of young trees, including suggestions that the Cylindraspis giant tortoises would have been more likely to disperse the seeds than dodos, casting doubt on Temple's view as to the dodo and the tree's sole survival relationship.
Uses
The dodo tree is highly valued for its wood in Mauritius, which has led some foresters to scrape the pits by hand to make them sprout and grow.
See also
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Sideroxylon majus, a species native to Réunion, that has been confounded with Sideroxylon grandiflorum (particularly under its synonym Calvaria major)
External links
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Catling, P. M. (2001): Extinction and the importance of history and dependence in conservation. Biodiversity 2(3): 2-13
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Helfferich, C. (1990): The Turkey and the Tambalacoque Tree
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Hershey, D. R. (2004): The widespread misconception that the tambalacoque absolutely required the dodo for its seeds to germinate. Plant Science Bulletin 50: 105–108.
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Hill, A. W. (1941): The genus Calvaria, with an account of the stony endocarp and germination of the seed, and description of the new species. Annals of Botany 5(4): 587–606. PDF fulltext (requires user account)
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King, H. C. (1946): Interim Report on Indigenous Species in Mauritius. Port Louis, Mauritius: Government Printer.
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Owadally, A. W. & Temple, Stanley A. (1979): The dodo and the tambalacoque tree. Science 203(4387): 1363–1364.
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Quammen, David (1996): The Song of the Dodo: Island Biogeography in an Age of Extinction. Touchstone, New York.
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Temple, Stanley A. (1977): Plant-animal mutualism: coevolution with Dodo leads to near extinction of plant. Science 197(4306): 885–886. HTML abstract
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Witmer, M. C. & Cheke, A. S. (1991): The dodo and the tambalacoque tree: an obligate mutualism reconsidered. Oikos 61(1): 133–137. HTML abstract
