Straight from the dragon’s mouth: myth of toxic komodo dragon bite busted

Scott Sutherland

Human history is full of examples of fearsome myths and legends about dragons, and according to a team of researchers led by scientists from the University of Queensland, our only living example of a dragon — the komodo dragon — has some myths and legends build up about it as well.

The komodo dragon is the world's biggest species of lizard. They're native to Indonesia, and they have a fearsome reputation for a rather lethal bite. It's not because they have massive razor-sharp teeth, like something you'd expect to see in a Jurassic Park movie, but instead it was thought that their saliva contained a 'soup' of bacteria that quickly causes a lethal infection in their prey. Studies had shown that any komodo dragons in captivity didn't have this combination of bacteria, and that their saliva was actually quite clean. This was thought to be based on them being fed a cleaner diet and also because of antibiotics used in their care.

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However, according to Dr. Bryan Fry, an associate professor at the University of Queensland who studies venomous animals, the work done by he and his American counterparts shows that the mouths of komodo dragons, even those in the wild, are very clean.

"Komodo dragons are actually very clean animals," he said in a University of Queensland news release.

"After they are done feeding, they will spend 10 to 15 minutes lip-licking and rubbing their head in the leaves to clean their mouth. The inside of their mouth is also kept extremely clean by the tongue. Unlike people have been led to believe, they do not have chunks of rotting flesh from their meals on their teeth, cultivating bacteria."

The myth, according to the research, arose based on what people saw from water buffalo that had been attacked by the dragons. When the researchers observed pigs and deer that had been attacked, the animals typically survived the encounter with serious wounds, but then later died by bleeding out (partly due to the venom that the dragons have in their saliva glands, which disrupts blood-clotting). However, for water buffalo, they also escaped, wounded, but then did what they always do to protect themselves...

"The water buffalo follow their instincts and seek shelter in warm water that is usually stagnant, filled with water buffalo faeces and flourishing with bacteria — particularly nasty anaerobic types," Dr. Fry said in the statement. "It is when the water buffalo go stand in the toxic water with gaping wounds that they get infected."

"It really has been that simple all along," he added. "If water buffalo had never been introduced onto the islands, then this enchanting fairy tale never would have come into existence. The water buffalo are not living in their native habitat of large fresh marshes, but rather on islands with the only water source being tiny water holes. So they are basically going to the bathroom directly onto their wounds. This is an ideal scenario for infection, but a situation that is man-made and thus entirely artificial."

As for where the bacteria came from that previous studies had found in komodo dragon mouths? According to this research, it's from drinking the stagnant water from those same pools the water buffalo hide out in. The next step for the researchers is to test the water from those pools, to not only prove that, but also see exactly which germs are killing the infected water buffalo.

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The komodo dragon is currently listed as a 'vulnerable species' by the International Union for Conservation of Nature, with about 4,000-5,000 estimated to still live in the wild, and their numbers are dwindling due to natural disasters like volcanic eruptions, fires and earthquakes, but also from loss of habitat, tourism and poaching.

Now exonerated of this particular nasty reputation, and with Dr. Fry describing Monty, the komodo dragon he's posing with in the picture, as "by far the most sentient reptile I have ever encountered. Intelligent enough to have an inquisitive and quite sweet personality," hopefully conservation efforts for the komodo dragon will gain more support and we can preserve this remarkable species.

(Photo courtesy: Dr. Bryan Fry/University of Queensland)

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