The Komodo Dragon: Deadly Drooler or Poisonous Predator?

The Komodo dragon (labeled "Vulnerable" by the IUCN) has long had the title of "World's Deadliest Drooler."  Native only to the Komodo Islands in Indonesia, The story went that the Komodo would bite its prey and let it slowly die, eaten away from the inside out by all of the deadly bacteria that fermented in its mouth.  It ends up that this story, as that is all it is, a story, originated from just one or two accounts of the creature almost a century or so ago, and that they were based almost entirely upon observation.  After these accounts were made public, more and more researchers and scientists tagged on to this idea until, eventually, it was a scientifically accepted fact.

Further support for this hypothesis was observations of Komodos biting buffalo, a main food source, and simply hanging around for days, weeks, and (I believe) on at least one occasion, a month.  Scientists believed that the animals would slowly succumb to the copious amounts of bacteria that were at home in the mouth of the worlds largest extant lizard. 

While it is true that the mouth of the Komodo dragon was, in fact, home to a number of very virulent strains of bacteria, it seems that there are other players at work.  A group of scientists noticed that the Komodo dragon, and other closely related monitor lizards, all had interesting bulges in the sides of their mouths.  These bulges they thought resembled those seen in the Gila monster, one of just two lizards that were previously known to have venom, the other being Mexico's beaded lizard.  Komodo skulls are hard to get a hold of, however, and it wasn't until 2009 that the team of researchers were finally able to get ahold of a Komodo dragon skull to put through an MRI machine.  The MRI scan showed that the Komodo did indeed have venom glands.  Although the venom appeared not to be deadly, it was potent enough to act as a sedative.  This, the team concluded, was how the Komodo would kill its victims: sedate them with its mildly potent venom, and then finish them off when they were slow and torporous. 

This didn't explain why it sometimes took weeks for Komodos to finish off a buffalo.  Kurt Schwenk believes it is because the Komodos often don't want to risk life and limb.  So what they do is they bite their victims, and let a combination of shock and bloodloss do the trick.  As the prey slowly starves, being surrounded by Komodo dragons and unable to retreat anywhere, more and more Komodos congregate in preparation of the coming feast.  And given their slow metabolic rates, they can afford to wait, too: unlike a lion or a cheetah, they are in no hurry to finish off their prey, and see no reason to take unnecessary risks to finish off the prey.

While all of this research is highly disputed, and subject to many different points of interpretation, it does seem like the idea of the Komodo killing by its toxic drool is indeed false, although only future research will decide all of this for certain.