Ile aux Aigrettes

Located in the Bay of Mahébourg, about 800 m off the southeast coast of Mauritius, these 26 ha of coralline limestone, partially overlain with sand and humus deposits, are what remain of an eroded dune exposed after a drop in the sea level some 10,000 years ago.
Previously much degraded and weed invaded, this islet is the last refuge of the dry coastal forest, an ecosystem once common around much of coastal Mauritius.
Free from human presence for a long time, Ile aux Aigrettes became a natural museum with a remarkable collection of endemic species of Mauritian fauna and flora. However, the arrival of man on the islet in the early 1600s disturbed and almost totally destroyed this island ecosystem. Tree felling continued even after the island was first declared a nature reserve, in 1965.

Restoration work on the island began with a weeding programme to eradicate introduced invasive plants such as the faux acacia Leucaena leucocephala and prune malgache Flacourtia indica.

This type of forest was once rich in the unique and Critically Endangered species of ebony Diospyros egrettarum, the Endangered bois de chandelle Dracaena concinna, and a species of orchid Oeoniella polystachys, amongst others. The next step was to eradicate introduced predators such as rats, paving the way for the reintroduction of native fauna. Interestingly, once the rats had gone there was a dramatic emergence of ebony seedlings.

In 1997, a nursery was built for the propagation of endangered native plants for replanting on the island. The nursery now produces about 6,000 plants per year of which most are planted on Ile aux Aigrettes, although some are sent to Round Island.  We also donate a few thousand plants to communities and social institutions on Mauritius (thanks to the support of Air Mauritius).

The entire island has now been weeded at least once and replanted with around thirty threatened endemic plant species.

With the re-establishment of native forest on the island we began to reintroduce the endemic species of birds and reptiles, which would once have populated Ile aux Aigrettes. The Mauritius Kestrel was the first species to be reintroduced.

However, it transpired that this unique bird of prey prefers the nearby mainland Bambous Mountains, and birds rarely come back to the island. Pink Pigeons, Mauritius Fodies and Mauritius Olive White-eyes have also been reintroduced, along with the Aldabra Giant Tortoise (to replace the extinct giant tortoise once found here), Telfair’s skink Leiolopisma telfairi and Guenther's gecko Phelsuma  guentheri. The beautiful endemic Ornate Day Gecko Phelsuma ornata still occurs on the island naturally. Captive Mauritius Fruitbats Pteropus niger can also be viewed on the island.

Ile aux Aigrettes has become a showcase for the work undertaken by MWF with animal and plant species unique to Mauritius found in a habitat restored, as closely as possible, to its natural state of 400 years ago. Members of the public have been able to visit the island since 1997 to experience for themselves this transformation as part of our awareness and ecotours project.