Archive for September, 2009

Nick Smith’s feature on wildlife conservation in Mauritius – ‘Miracle Workers’ – as published in Geographical magazine, October 2009

September 22, 2009

Miracle workers

When Gerald Durrell helped establish the Mauritius Wildlife Foundation 25 years ago, few could have predicted the overwhelming success of many of the organisation’s conservation projects. Words and photography by Nick Smith

Sitting in his office, windows flung open against a blisteringly hot day, Vikash Tatayah points to a painting of a bird of prey on the wall behind him. He explains that the copper-coloured kestrel is the symbol of the Mauritian Wildlife Foundation (MWF) of which he is the Conservation Manager. He’s just about to depart for neighbouring Mascarene island Rodrigues and can’t be late. He’s also writing his doctoral thesis and there’s a steady stream of colleagues knocking on his door asking detailed questions about various aspects of field science. He’s obviously in demand and the MWF headquarters in Vacoas is a busy place.

I’ve come to visit Tatayah to find out about the origins of the MWF that’s currently celebrating its 25th anniversary. It’s a story revolving around the legendary British author and wildlife conservationist Gerald Durrell. But as Tatayah says, in order to understand what was happening on Mauritius a quarter of a century ago, you need to understand what happened 400 years ago, when the country was first discovered and colonised. Over the past four centuries there has been large-scale clearance of the native forest to make way for agriculture and human development. Sugar was the king crop and from the word go every conceivable pocket of land that could be found for its cultivation was exploited. All that remained of the forest were tiny fragments high up in the mountains: in fact there is now less than 1.5% of native forest left on Mauritius.

Deforestation, hunting and introduced species all had their effect on the biodiversity of Mauritius, which now has one of the highest extinction rates of birds, mammals and reptiles in the world. The lowest point for biodiversity was in the 1970s when the country could boast the rarest pigeon, parrot and bird of prey. But it wasn’t just birds that were on the brink. There were also habitats that were seriously degraded, including Round Island that, while rich in reptiles, had lost most of its forest to introduced goats and rabbits. Meanwhile the Rodrigues fruit bat become rare and had declined to perilously small numbers.

At this point the Gerald Durrell enters the story. He and his assistant John Hartley arrived on Mauritius in 1976 originally with the intention of – according to Tatayah – ‘lying on the beach, drinking lots of tea and whisky, smoking a lot and writing a book.’ But the government invited the naturalists to review their conservation projects. They are shown the pink pigeon, the Mauritius Kestrel, taken to Round Island and to see the golden bats of Rodrigues (later immortalised in Durrell’s book Golden Bats and Pink Pigeons). Upon being shown the extent of the decline of biodiversity on Mauritius, Durrell offered to start a captive breeding programme for some of the rare birds at his Durrell Wildlife Conservation Trust in Jersey (as Durrell Wildlife was then called).

By the 1980s it was clear that there was a pressing need for an NGO dedicated to wildlife conservation on Mauritius capable of raising funds internationally. Durrell was the catalyst and the Mauritian Wildlife Appeal Fund was created in 1984. A quarter of a century and a name-change later the organisation employs around 130 staff (including volunteers) making the MWF not only the largest conservation NGO in the region, but the sole terrestrial wildlife conservation body for Mauritius and Rodrigues. The MWF is working on more than 20 bird, reptile, education, eco-tourism, habitat restoration and rare plant conservation projects and runs eight field stations: five within the Black River Gorges National Park and one apiece on Rodrigues, Round Island, Ile aux Aigrettes.

Birds, bats and giant tortoises

Although there have been other pink pigeons endemic in the Mascarenes, the Mauritian Pink Pigeon is the only survivor, and only just. The reason it’s become rare is because of habitat degradation and there are only a few pockets of suitable habitat remaining. The pink pigeon conservation project takes place on Ile aux Aigrettes, a tiny island on the southeast corner of Mauritius that has been cleared of predators and where the habitat has been restored.

When Durrell first came to Mauritius there was only one pink pigeon population, and that was at the appropriately named Pigeon Wood on the mainland where there was an estimated 12-20 birds in total. Although this total may seem low at its all-time low in 1990 there were only nine birds in existence. A PVA (population viability assessment) was done which concluded that the most likely outcome was that the pink pigeon would die out by 2000. Today, there are six sub-populations, with a total of 420 regularly observed birds. This success means the bird has been down-listed on the IUCN Red List from ‘critically endangered’ to ‘endangered’. Tatayah says that the MWF is talking to Birdlife International about down-listing the pink pigeon further to merely ‘vulnerable’.

The Mauritius Kestrel shares with the pink pigeon a steep decline and almost miraculous recovery, although the reason for its near extinction is quite different. In the twentieth century, one of the biggest health problems on Mauritius facing the human population was malaria and during the Second World War it was discovered that the synthetic pesticide dichlorodiphenyltrichloroethane (or DDT) was extremely good at eradicating the mosquitoes that transmitted it. And so DDT was sprayed in high concentrations all over Mauritius. It wasn’t until decades later that scientists came to realise that it was also extremely good at eradicating birds of prey (although other organophosphates had also played their part). As a result the Mauritius Kestrel became the rarest bird in the world – in 1974 there were only four left (with only one breeding female). With the aid of the Peregrine Fund, the Durrell Wildlife Conservation Fund and the ICBP (now Birdlife International) the MWF set up a captive breeding programme that reared and reintroduced several hundred hatchlings into three mountain ranges on the island. It’s estimated that there are now more than 600 free flying kestrels in the wild, making it as Tatayah claims ‘the most successful bird restoration project in the world.’

Originally, the only herbivores in the Mascarenes were tortoises and the highest density anywhere in the world was on Rodrigues. When the first settlers arrived they found the island covered with them and in some places you could walk a hundred paces on their backs without setting foot on the ground. The settlers over-harvested them for food, and within a few decades the entire population became extinct.

Tortoises have a significant influence on botanical ecology by controlling grasses, and dispersing seeds through their droppings. After their extinction in the Mascarenes the ecological functions they served such as selective grazing and seed dispersal, were not taken up by any other species. According to Tatayah, for a number of years the MWF debated what species could be introduced, not to replace the tortoise, but to plug the evolutionary gap left by the species. ‘It’s like a jigsaw puzzle’ he says. ‘It’s sad if you lose a piece, but if you can find a replacement part that maintains the integrity of the puzzle then, so long as it’s not an invasive species, why not?’

The MWF has experimented with the introduction of two different Indian Ocean tortoises: the Giant Aldabra from the Seychelles and the Madagascan radiated. Trials on Ile aux Aigrettes have shown that these tortoises are important in maintaining the low swathe of grass and are helping biologists to understand the co-evolution of plants and animals in the Mascarenes. Currently there are 20 tortoises on Ile aux Aigrettes, free roaming and breeding well. ‘It’s like having twenty labourers on the island’ says Tatayah. ‘They do the weeding and plant seeds. We’ve found that seeds dispersed by tortoises germinate better than those that simply fall off the tree and grow.’ Tatayah believes that tortoises can eventually return to the mainland – possibly to the Black River Gorges National Park – where they could play a part in controlling invasive plants.

Facing the future

What Mauritius needs, says Tatayah, is a halt to the invasion of exotic species. ‘We have a large number of plants and animals that are causing great havoc and so we need for an effective quarantine policy so that no more invasive species enter into the country.’ But alongside deceleration of the invasion it is also a requirement to restore the native forest.

The MWF estimates that 6,000 hectares of forest are needed to establish a self-sustaining ecological balance on the island. The sheer scales of such a project presents a huge environmental challenge for Mauritius. One of the ways of achieving this is to reclaim so-called marginal land. In Mauritius most of the sugar plantations are planted right up to the foothills of the mountains. These lower-yield areas are no longer profitable for agriculture because of the fall in global sugar prices, but would assist in reclaiming the forest, which is rich in indigenous biodiversity, including many species of critically endangered snail. The top third of the island’s mountains have been kept as forest fringe due to a law passed in the French colonial days. ‘But one of the things we would like to do’ says Tatayah ‘is to go down-slope. We need to see if we can reverse the trend by reclaiming these marginal areas. So instead of the agriculture encroaching we want the forest to reclaim the land.’

The MWF has been pushing for a policy to restore the marginal lands and it has become one of the highest recommendations in the National Forestry Policy Action Plan. But the big question is whether there is the political will for this to happen. ‘It’s very difficult to convince a politician that a snail on top of a mountain is important. If the snail could vote, that would be a different thing.’

For further information on, or to make a donation to, the Mauritian Wildlife foundation visit www.mauritian-wildlife.org