We heard him complain regularly and bitterly during our time on Mauritius that he was no good at administration or politics, and yet to keep his work going he had to spend an awful lot of time doing both. He had constantly to work raising money, justifying and accounting for the money he gets to the people he gets it from, and negotiating with the various international conservation bodies who seem to watch over his shoulder all the time. As far as he's concerned it just prevents him from doing the work he's best able to do, and he wishes they'd leave him alone and let him get on with it. Or rather, give him the money and then leave him alone and let him get on with it. The whole project, to save the fragile and unique ecology of Mauritius , is run on a pathetically meagre budget, and money - or the lack of it - is the bane of Carl's life. He left in a harassed fluster.

`You'd think that everyone involved in conservation work would be on the same side,' said Mark after he'd gone, 'but there's just as much squabbling and bureaucracy as there is in anything else.'

`You're telling me,' said Richard. `And it's always the workers out in the field who get mucked about by it. Look at these rabbits.'

With a contemptuous wave of his hand he showed us a cage in which a few perfectly ordinary looking rabbits sat twitching at us.

`There's an island near here - a very, very important island as far as wildlife is concerned - called Round Island . There are more unique species of plants and animals on Round Island than there are on any equivalent area on earth. About a hundred, hundred and fifty years ago somebody had the bright idea of introducing rabbits and goats to the island so if anybody got shipwrecked there they'd have something to eat. The populations quickly got out of hand and it wasn't until the mid-seventies that they managed to get rid of the goats. Then just a few years ago a team from New Zealand came to exterminate the rabbits, until someone realised that they were exterminating a rare breed of French rabbit that didn't exist any more in Europe and it should therefore be transferred to mainland Mauritius and preserved in some way, i.e. by us.

`As far as I'm concerned,' continued Richard, 'we could just put them in the pot. They're just ordinary rabbits. Also, since then someone has come along and said, "That's a load of rubbish - these aren't that particular variety."

`So we've just got to sit here feeding these rabbits until the rabbit experts have decided whether they're valuable or not. It's a waste of our time and resources. I mean just feeding all these animals is a problem. They all need something different and you have to work out what it is.

These Rodrigues fruitbats you've come to see, we have to feed them on a mixture of fruit and powdered dog food reconstituted with milk. They used to be fed a diet rich in banana which did them no good at all and only gave them a nervous tic.' He shrugged.

`I don't know what you've got against them,' said Mark, 'I think they're great animals.'

'I've nothing against them. They're great. They're just common that's all.'

Mark protested, `It's the rarest fruitbat in...'

'Yeah, but there are hundreds of them,' insisted Richard.

`Hundreds means they're severely endangered!' said Mark.

'Do you know how many echo parakeets there are in the wild? exclaimed Richard, 'Fifteen! That's rare. Hundreds is common. When you come to Mauritius and you see things in such a last ditch state, everything else becomes unimportant. It becomes unimportant because we're witnessing here a species which could be saved if people put their minds to it, and if it does go extinct it will be our fault because we never got around to saving it. There's fifteen of them left. We've got the kestrels up and the pigeons up purely because of the effort we've put into them, the money and the personnel. The parakeets? We're working very, very hard to save them, and if we don't manage it they will be gone for ever, and we have to worry about somebody else's rabbits.'

He shook his head, and then calmed down.

`Listen,' he said to Mark. `You're right. The Rodrigues fruitbat is a very important animal, and we are working to protect it. It's lost a lot of its habitat because the people of Rodrigues live by subsistence farming which means that they've done a lot of forest clearance. The bat population is so reduced that one big cyclone - and we get them here - could wipe them out. But the Rodriguans have suddenly realised that it's actually damaging their own interests to cut down the forest, because it's reducing their water supply. If they want to preserve their watersheds they have to preserve the forests, which means the bats get somewhere to live. So they're in with a chance. By the world's standards they're severely endangered, but by the standards of these islands where every indigenous species is endangered, they're doing fine.'

He grinned.

`Want to see some endangered mice? he said.

'I didn't think mice were an endangered species yet,' I said.

'I didn't say anything about the species,' said Richard. 'I just meant the particular mice. Conservation is not for the squeamish. We have to kill a lot of animals, partly to protect the species that are endangered, and partly to feed them. A lot of the birds are fed on mice, so we have to breed them here.'

He disappeared 'into a small, warm, squeaking room and re-emerged a few seconds later with a handful of freshly killed mice.

`Time to feed the birds,' he said, heading back towards the Landrover from hell.

The best and quickest road to the Black River gorges where the kestrels live is a private one through the Medine sugar estate.

Sugar, from the point of view of the ecology of Mauritius , is a major problem. Vast swathes of the Mauritius forest have been destroyed to provide space to grow a cash crop which in turn destroys our teeth. This is serious anywhere, but on an island it is a very special problem, because island ecologies are fundamentally different to mainland ones. They even have a different vocabulary. When you spend much time on islands with naturalists you will tend to hear two words in particular an awful lot: `endemic' and 'exotic'. Three if you count 'disaster'.

An 'endemic' species of plant or animal is one that is native to an island or region and is found nowhere else at all. An 'exotic' species is one that has been introduced from abroad, and a disaster is usually what results when this occurs.

The reason is this: continental land masses are big. They support hundreds of thousands, even millions, of different species, each of which is competing with another for survival. The sheer ferocity of the competition for survival is immense, and it means that the species that do survive and flourish are mean little fighters. They grow faster and throw out a lot more seeds.

An island, on the other hand, is small. There are far fewer species, and the competition for survival has never reached anything like the pitch that it does on the mainland. Species are only as tough as they need to be, life is much quieter and more settled, and evolution proceeds at a much slower rate. This is why you find on, for instance, Madagascar , species like the lemurs that were overwhelmed aeons ago on the mainland. Island ecologies are fragile time capsules.

So you can imagine what happens when a mainland species gets introduced to an island. It would be like introducing AI Capone, Genghis Khan and Rupert Murdoch into the Isle of Wight - the locals wouldn't stand a chance.