How dangerous is a Komodo dragon?

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Raja has been trained not to bite

A group of divers stranded on a remote island had to fight off a "man-eating" Komodo dragon. How dangerous are these creatures really?

When three Britons were washed up on a remote Indonesian island, their relief must have been immense.

For 12 hours they and two other divers had been clinging to each other in shark-infested waters after being carried from their diving boat by currents.

But wracked by dehydration and exhaustion, their joy at reaching Rinca island was short-lived when a Komodo dragon appeared on the beach. They pelted it with rocks and it retreated, and the five divers were later rescued.

Komodo dragons are known to have killed and eaten humans. So how dangerous are are they?

Dr Ian Stephen is assistant curator of herpetology (reptiles and amphibians) at London Zoo, where he looks after two Komodo dragons. Raja is an adult male, 10 years old, and Raja's daughter Sayang is nearly two.

Potentially they are very dangerous animals, he says, but it helped that the divers stayed on the beach.

THE ANSWER In the wild they are very dangerous and would attack humans unprovoked They bite their prey and their saliva has 80 strains of bacteria They then wait two days for it to die and feast as a group on the kill

"They will eat anything that washes up on the beach. That's why these people would have been in danger. When you have animals on the brink of starvation they will be very aggressive and humans are not very powerful.

"If you have a couple of people throwing stones or sticks, that can work as long as you are only dealing with one or two [dragons]. They were in danger but they did the right thing.

"They can move incredibly quickly over short distances. The danger would have been when people started looking for food and headed inland, into long grass."

A Komodo dragon's favoured method of attack is to lie in the bushes and long grass and then pounce on their prey, usually deer, feral pigs or water buffalo. It also eats carrion.

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Pound for pound they are incredibly powerful, says Dr Stephen, the largest lizard in the world measuring up to three metres long (9ft 10ins) and 120kg (265 lbs). And they are strong swimmers so could follow a fleeing human into the sea.

"Generally they attack their prey but don't kill it there and then. They have a poisonous saliva full of different bacteria, about 80 species of bacteria. So in a couple of days septicaemia sets in and the prey dies."

Contrary to some reports they do not spit venom, he says, but their teeth are shark-like and leave a very nasty and poisonous bite. If the wounded prey gets away the dragon can follow a blood trail a couple of miles away.

KOMODO DRAGON World's largest lizard, up to 3.1m and 126kg Capable of 'virgin births' without a male Numbers estimated at 4,000 on four Indonesian islands In captivity there is an acute shortage of females Nicknamed 'buaya darat' or land crocodile

A kill usually attracts many dragons who feed according to their own hierarchy.

Humans living on the islands within the national park habitat of the dragons have learnt how to adapt to the dangers. Their houses are on stilts.

Although attacks on humans are rare, an eight-year-old German boy was mauled to death there in 2007.

Dr Stephen says a Komodo dragon in the wild would not hesitate to kill and eat a human if they wanted to, but Raja has been trained and is quite tame.

He is fed deer, rabbits or wild boar every four to eight weeks. He eats the whole prey - skin, bone and hair. Sometimes he regurgitates some of the bones.

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He seems to enjoy human interaction, especially being stroked, but there are occasional, sharp reminders of his strength.

"When Raja has a blood test, it takes two men to restrain his tail. You can't imagine the power in this animal and he's only 54kg. Imagine one that was 120kg."

In the wild, the tail is used as defence or to compete with other dragons for the meat of a big kill.

Fortunately, the dragons on Rinca island were denied a human meal at the weekend.