Saturday, 8 May 2010

Pigeons of Bristol 9: And finally ...

Of all the endangered pigeons currently on show at Bristol, the species I am most proud we have is one of the rarest in the world, the Mauritius Pink Pigeon Nesoeanas mayeri. As the last surviving endemic pigeon of the Mascarenes (Mauritius and its related islands of Reunion and Rodrigues) it is of very considerable interest.

The exact taxonomic position of the Pink Pigeon has been unclear, and it has been placed in either the Old World pigeon genus Columba (along with the Rock Dove), or with the Collared Doves in Streptopelia. It seems to belong, with its much smaller relative the Madagascar Turtle Dove, in a separate clade, and is now placed in Nesoeanas. It appears that its ancestors colonised Mauritius from Madagascar some millions of years ago and evolved there, later colonising the younger island of Reunion. Reunion Pink Pigeons (now sadly extinct) have been placed in a separate subspecies, but were apparently very similar.

Today the Pink Pigeon is the subject of intensive effort to rehabilitate the species. Bristol Zoo has bred them in the past, but it has proven extremely difficult to breed outside of Mauritius, and there are currently 46 in European zoos (including four at Bristol), with another 36 in the USA.

On Mauritius itself the Mauritius Wildlife Foundation has been more successful, and there are now 6 sub-populations. As of February 2009 the wild population stood at 422 birds. This sounds very small, but is a considerable improvement on the situation in 1986, when only 12 birds could be found at the only site they survived in.

Aside from predators, the main threat appears to be habitat degradation. Pink Pigeons are adapted to feed both on the ground and at the end of long branches, and deforestation and introduced plants do not provide the correct food. Fortunately they take readily to bird tables, so supplemental feeding is easy to provide. Indeed, there was an attempt to release birds in one of the botanic gardens on Mauritus. The birds survived, and even bred, but were wiped out by small boys with catapults, for whom they made easy targets.

As the Reunion Pink Pigeon was closely related to the Mauritius form, which was its ancestor, it might be possible in the future to reintroduce them to Reunion. Unfortunately, at this point politics intervenes. Whereas Mauritius, with Rodrigues, was a British colony and is now independent, Reunion is a French Overseas Department, so there is less connection between conservation on Mauritius and Reunion than there should be.

This brings this series on Bristol Zoos animals to a close – next week, the strangeness of gibbons (they have even more specializations than you think!)

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