The logo of the Darwin Initiative: a finch

Rebuilding reptile communities

A collaborative project between Mauritian Wildlife Foundation, the Durrell Wildlife Conservation Trust and the National Parks and Conservation Service of Mauritius.

The project is managed by Dr Nik Cole and funded by Defra's Darwin Initiative.

In 2006 the project initiated the first lizard translocations within the Indian Ocean. This has involved the movement of five endemic and vulnerable lizard species back to islands where they used to occur.

Unfortunately there are not many people that consider reptiles as being very nice, but they are incredibly important to our ecosystem, particularly in Mauritius. Before people arrived in Mauritius some 400 years ago there were no cats, dogs, deer, rats or any other mammal except for bats. It was an island of unique reptiles and birds. The reptiles did so well that they adapted to fill many of the roles that mammals usually occupy. There were giant tortoises that were the grazers and browsers, harmless snakes that ate smaller reptiles and birds, large lizards that were also predators and with the smaller lizards helped disperse the seeds of Mauritian trees and pollinate their flowers. The reptiles were so successful that for the size of the islands Mauritius and Rodrigues were once home to more unique species than anywhere else in the World.

A map of Mauritius
© Nik Cole
Map of Mauritius

However, when people arrived in Mauritius they introduced numerous animals and plants from elsewhere and cut down much of the original Mauritian forests. These disturbances caused the loss of more than 60% of the unique Mauritian reptiles from the main island. Five reptile species died out completely and because they were unique to Mauritius, not being found anywhere else, they went extinct. Some managed to persist on a few of the offshore islands, particularly those that had not been invaded by predatory mammals, such as rats, which have been responsible for much extinction worldwide. For Rodrigues it was much worse, all of the endemic reptiles became extinct.

Islands like Round Island, to the north of Mauritius were never invaded by rats and therefore became the last place in the World to have the large Telfair's skink, the giant Guenther's day gecko, two harmless snakes the Burrowing boa and the Keel-scaled boa (although the burrowing boa has not been seen since 1975) and the Durrell's night gecko.

Other introduced animals like cats, mongoose, shrews, couleuvre, house geckos and Madagascan geckos have contributed to the destruction of the unique Mauritian reptiles. Currently the majority of Mauritian reptiles are restricted to either Round Island or one or a few of another six out of 49 islands around Mauritius.

A photo of Round Island
© Nik Cole
Round Island.

Over the last three decades the project partners have been instrumental in restoring the northern and southeastern offshore islands. They have removed most of the problematic introduced animals, such as rats, cats, mice, hares, rabbits and goats and are restoring habitats by replanting endemic Mauritian species. All this hard work has made it possible to start moving unique reptiles back to islands where they used to occur. The re-establishment of new reptile populations reduces the risks of extinction, thus strengthening the long term sustainability of the unique Mauritian biodiversity.

Since 2006 we have moved five reptile species to four islands:

A Telfair's skink on the ground
© Nik Cole
Telfair's skink

The Telfair's skink (Leiolopisma telfairii)

Once widespread throughout Mauritius, this large lizard has been marooned on Round Island for more than 150 years because rats have caused their demise in all other locations. Round Island therefore became the last place in the World where you could still find this animal. We have moved individuals to Ile aux Aigrettes in the southeast and Gunners Quoin in the north where they are starting new populations. We are finding that these lizards are helping us in restoring islands, by reducing the numbers of other problematic introduced animals that we cannot remove, such as the shrew and wolf snake and dispersing many endemic seeds from plants such as Ebony. Gunners Quoin and Round Island are closed nature reserves and access is prohibited. Ile aux Aigrettes is also a nature reserve, but is open to the public who may visit the island with tour guides from the Mauritian Wildlife Foundation.

A Bojer's skink on a rock
© Nik Cole
Ilot Vacoas Bojer's skink

A rare form of Bojer's skink (Gongylomorphus bojerii sp.)

Once widespread through the southeastern area of Mauritius, this small skink has been marooned for some time on the tiny island Ilot Vacoas. This lizard was lost from all other locations because of predation by the introduced shrew and the wolf snake, although other introduced predators have also contributed. We have moved individuals back to Ile aux Fouquets (also known as Ile aux Phare) from Ilot Vacoas, where they are repopulating the island. Ilot Vacoas is a closed nature reserve and as such access is prohibited. These small skinks mostly eat insects, but will also eat fruits and thus disperse their seeds.

An orange-tail skink on the ground
© Nik Cole
Orange-tail skink

The orange-tail skink (Gongylomorphus fontenayi sp.)

Very little is known about the past distribution of this skink, but is thought to have once been found throughout the lowlands of Mauritius. Like the Bojer's skink predation from the introduced shrew and the wolf snake are likely to have been the cause of its restriction to Flat Island, its last refuge. To secure the skinks survival we have moved individuals to Gunners Quoin, where all initial observations show that they are doing extremely well and are starting to produce offspring.

The Durrell's night gecko (Nactus durrelli)

Durrell night gecko on a rock
© Nik Cole
Durrell's night gecko

This small nocturnal gecko that lives on the ground was once widespread throughout Mauritius and the islands, but for many years it has been restricted to Round Island. House geckos, shrews, wolf snakes and rats were responsible for the loss of this gecko from all other locations. To start a new population of geckos we moved individuals from Round Island to Ilot Chat.

The lesser night gecko (Nactus coindemirensis)

This tiny nocturnal gecko is similar to the Durrell's night gecko, but much smaller and was probably the most abundant reptile to have lived in Mauritius.

A lesser night gecko on a rock
© Nik Cole
Lesser night gecko

Like its larger cousin, this gecko was once widespread in Mauritius, but house geckos with shrews, wolf snakes and rats restricted the lesser night gecko to very small areas on four islands. To start a new population of the lesser night gecko we moved individuals from Ilot Vacoas to Ilot Chat with the Durrell's night gecko.

Do you want to know more?

If you would like to know more about the reptiles or if you live in Mauritius and want to find out what you have in your garden or your house, the Mauritian Wildlife Foundation are producing a colourful Guide to the reptiles and amphibians of Mauritius, which will be available from August 2008. Ile aux Aigrettes also offers the public and visitors to Mauritius a unique opportunity to view what Mauritius was like before people arrived and where you can see conservation in progress.

For details of my completed PhD project, please see The impact of invasive species on reptile communities.

Contact details

Dr Nik Cole
Mammal Research Unit
School of Biological Sciences
University of Bristol
Woodland Road
Bristol BS8 1UG, U.K.

Telephone: 0117 9287593
Email: Dr Nik Cole