'So they're not particularly endangered?

`Well, they are, because only three hundred and fifty of them are breeding females. We don't know if that's a typical number or not, but it seems pretty low. Furthermore, if an animal has a low population and lives in a very restricted area, like just a few small islands in the case of the dragons, it's particularly vulnerable to changes in its habitat, and wherever human beings arrive, habitats start changing pretty quickly.'

'So we shouldn't be here.'

'It's arguable,' said Mark. 'If no one was here taking an interest the chances are very strong that something could go wrong. just one forest fire, or a disease in the deer population could wipe out the dragons. And there's also the worry that the growing human population on the islands would start to feel that they could very well live without them. They are very dangerous animals. There's not merely the danger of being eaten by one. If you just get bitten you are in very serious trouble. You see, when a dragon attacks a horse or a buffalo, it doesn't necessarily expect to kill it there and then. If it gets involved in a fight it might get injured, and there's no benefit in that, so sometimes the dragon will just bite it and walk away. But the bacteria that live in a dragon's saliva are so virulent that the wounds will not heal and the animal will usually die in a few days of septicaemia, whereupon the dragon can eat it at leisure. Or another dragon can eat it if it happens to find it first - they're not really fussed. It's good for the species that there is a regular supply of badly injured and dying animals about the place.

There was a well-known case of a Frenchman who was bitten by a dragon and eventually died in Paris two years later. The wound festered and would just never heal. Unfortunately there were no dragons in Paris to take advantage of it so the strategy broke down on that occasion, but generally it works well. The point is that these things are buggers to have living on your doorstep, and though the villagers on Komodo and Rinca have been pretty tolerant, there has been a history of attacks and deaths and it's possible that as the human population grows there will be a greater conflict of interest and rather less patience with the idea of not being able to go off for a wander without running the risk of having your leg bitten off and your entrails ripped out by a passing dragon.

'So, as we've discovered, Komodo is now a protected national park. We've got to the point where it takes active and deliberate intervention to save rare species, and that's usually sustained by public interest. And public interest is sustained by public access. If it's carefully controlled and disruption is kept to a minimum then it works well and is fine. I think. I won't pretend that I don't feel uneasy about it.'

'I feel very uneasy about the whole place,' said Gaynor with a shudder. `There's a kind of creeping malignancy about it.'

Just your imagination,' said Mark 'For a naturalist it's paradise.'

There was suddenly a slithering noise on the roof of the terrace, and a large snake fell past us to the ground. Instantly a couple of park guards rushed out and chased the thing off into the bush.

'That wasn't my imagination,' said Gaynor.

'I know,' said Mark, enthusiastically. 'This is wonderful.'

In the afternoon, accompanied by Kiri and a guard, we went off to explore. We found no dragons, but as we thrashed recklessly through the undergrowth, we encountered instead a bird, and it was one that I felt very much at home with.

I have a well-deserved reputation for being something of a gadget freak, and am rarely happier than when spending an entire day programming my computer to perform automatically a task that it would otherwise take me a good ten seconds to do by hand. Ten seconds, I tell myself, is ten seconds. Time is valuable and ten seconds' worth of it is well worth the investment of a day's happy activity working out a way of saving it.

The bird we came across was called a megapode, and it has a very similar outlook on life.

It looks a little like a lean, sprightly chicken, though it has the advantage over chickens that it can fly, if a little heavily, and is therefore better able to escape from dragons, which can only fly in fairy stories, and in some of the nightmares with which I was plagued while trying to sleep on Komodo.

The important thing is that the megapode has worked out a wonderful labour-saving device for itself. The labour it wishes to save is the time-consuming activity of sitting on its nest all day incubating its eggs, when it could be out and about doing things.

I have to say at this point that we didn't actually come across the bird itself, though we thought we glimpsed one scuttling through the undergrowth. We did, however, come across its labour-saving device, which is something that it's hard to miss. It was a conical mound of thickly packed earth and rotting vegetation, about six feet high and six feet wide at its base. In fact it was considerably higher than it appeared because the mound would have been built on a hollow in the ground which would itself have been about three feet deep.

I've just spent a cheerful hour of my time writing a program on my computer that will tell me instantly what the volume of the mound was. It's a very neat and sexy program with all sorts of pop-up menus and things, and the advantage of doing it the way I have is that on any future occasion on which I need to know the volume of a megapode nest, given its basic dimensions, my computer will give me the answer in less than a second, which is a wonderful saving of time. The downside, I suppose, is that I cannot conceive of any future occasion that I am likely to need to know the volume of a megapode nest, but no matter: the volume of this mound is a little over nine cubic yards.

What the mound is is an automatic incubator. The heat generated by the chemical reactions of the rotting vegetation keeps the eggs that are buried deep inside it warm - and not merely warm. By judicious additions or subtractions of material from the mound the megapode is able to keep it at the precise temperature which the eggs require in order to incubate properly.

So all the megapode has to do to incubate its eggs is to dig three cubic yards of earth out of the ground, fill it with three cubic yards of rotting vegetation, collect a further six cubic yards of vegetation, build it into a mound, and then continually monitor the heat it is producing and run about adding bits or taking bits away.

And thus it saves itself all the bother of sitting on its eggs from time to time.

This cheered me up immensely, and the good mood it put me into lasted all the way back to the visitors' village and up to the precise point when we walked in through the door of the but which we had been assigned as sleeping quarters.

It was quite large and constructed, as I have said, on stilts -for obvious reasons. However, the wood of which it was built was half rotten, there were damp and stinking mattresses in the small bedrooms, ominously large spiders' webs in all the corners, dead rats on the floor and the stench of an overflowing lavatory. We tried gamely to sleep there that night, but in the end were driven out by the sheer noise of the rats fighting the snakes in the roof cavity, and eventually took our sleeping bags down to the boat and slept on its deck.

We awoke early, cold and damp with the dew, but feeling safe. We rolled up our bags and made our way back along the rickety jetty and under the arch. Once again, as soon as we had passed through the arch the smell of the place assailed us and we were in that malign other world, Komodo.

This morning, we had been told, we would definitely see dragons: Big dragons. We didn't know precisely what it was we were in for, but clearly it was not what we had originally expected. It didn't look as if we would be pegging a dead goat out on the ground and then hiding up a tree all day.