The Other Mauritius – Lessons in Island niches

We gently negotiated the shallows close to the island and pulled up against a wooden jetty.  We disembarked and stretched our legs, and of course the first thing we did was look back to the mainland from where we had come.  We were taken by the tall slim guy to a collection of huts inland from the jetty.  In a small room that he called a museum, we were given an introduction to the foundation and its work.  He was very eloquent, speaking in both French and English to the mixed group.  The foundation had been set up in the 1970s to restore populations of various animals and plants that were on the verge of extinction.  The museum was devoted partly to those that had got away – those species who were already extinct before the foundation was able to do any good.  But they were rightly proud of their success stories.  After all I had seen for myself the released populations of Mauritian kestrels and pink pigeons in the Black River Gorges National Park. One of the most fascinating exhibits in the museum was a model of the Giant Skink, and animal that has been estimated to have been extinct since the 1650s.

It looked like any skink I have seen, the neat little lines of scales along its back, its slightly rounded but sleek looking head and the beady black eyes.  But the model, a life size, is nearly a metre long.  This would have been more like an iguana than the little friendly lizards that run up and down the walls of many a tropical house.  We also learnt of the Rodrigues and Mauritius Tortoises, with the most enormous necks to reach up to the fruits in the shrubs around.  Another magnificent sculpture gives an idea of what incredible creatures these must have been , before they too became extinct once man colonised the Mascarenes.

Sober to reflect on the losses but we also wanted to see the success stories, so we started our tour of the island.  First of all, our meticulous guide wanted to explain the importance of the vegetation.  He had a good reason too:  He was trying to make us understand a little as to why animals on Mauritius had become endemic species.  He showed us all manner of plants whose seeds had washed up on the shores and they had colonised the difficult volcanic and limestone rocks.  Many travelled in coconuts, hence the palms, some may have come by wind or inside birds guts or stuck to their exteriors.  Then the animals have arrived somehow – perverse in some cases.  Maybe it was plate tectonics which had separated species from their continental brothers, or perhaps bizarre cast away stories of animals stuck to branches, seeds or whatever.  But once on their own little island kingdoms they could become masters of both their environment and fellow creatures.  Each tried to find a niche.  The vegetation was dry and scrubby but quite thick.  The ground cover was available to a large number of creatures, but if by evolution you could breed in longer necks, some animals gained an advantage in reaching the further branches and have more food just for themselves.  This explained the anatomy of the tortoises.

There was evidence that some plants had evolved to take advantage of their relationships with the tortoises.  Some plants ensured their succulent leaves, flowers and fruits were at the tops of their structures; only reachable by one tortoise.  Fruits in particular could be passed through the tortoises’ digestive systems and excreted with all the other rich manure – a perfect place for a new plant to get a grip in a difficult rocky environment.

Then came a difficultly for some of these plants.  When species went extinct, the symbiotic relationship was broken, and the plants found it difficult to reproduce.  MWF are trying to overcome this now by introducing species which fit certain ecosystem niches.  In the case of the old tortoises they have introduced the only giant tortoise that still exist in the Indian Ocean, the Aldabara Giant Tortoise from the Seychelles.  They have long necks (not quite as giraffe-like as the Mauritian ones they replace), and are starting to assist in restoring the vegetation on the island back to how it might have been in the old days.

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