Anecdotal data on complications following V. komodoensis bites triggered scientific interest and were at first explained by the potential existence of pathogenic bacteria unique to the lizards’ oral flora. The origin of this idea dates back to folk myths; however, Auffenberg is often quoted as the originator of it. In his monumental 1981 study, he reports the presence of Staphylococcus sp., Providencia sp., Proteus morgani and Proteus mirabilis in mucoid samples from the external gum surface of the upper jaw of two freshly captured “oras” (the local name for V. komodoensis). In the same study, the specimen from the San Diego Zoo possessed none of these bacteria, and Auffenberg suggested that oras may depend on frequent reinfestation from carrion to replenish their “weaponised bacteria”. Though Auffenberg concludes that Proteus-dominated infection could be responsible for the consequences of some of the recorded bites and could potentially play an adaptive role in V. komodoensis ecology, he himself concludes “that the infectious feature of an ora bite is a folk myth”.

It was not until very recently, however, that the idea was definitively discarded, since research by us revealed that V. komodoensis oral flora turned was not at all dissimilar from that of any other carnivorous animal. The sensational reports of buffalo dying from infection are not only exaggerations about the frequency of what is a rare event, but they are also a fundamental misreading of scenario with recent anthropogenic origins—V. komodoensis evolved in Australia, alongside two larger species of varanid lizard, and subsequently radiated into Indonesia. Water buffalo, on the other hand, were introduced to the islands only 300 years ago by Dutch settlers. In their native environment water buffalo frequent vast marshes, whilst on the islands of Komodo and Rinca, which they share with V. komodoensis, the only available water sources are stagnant rocky pools measuring only 5–10 m across. V. komodoensis attacks upon water buffalo are invariably unsuccessful. However, subsequent to seeking refuge in watering holes filled with their own sewage, water buffalo may become infected with pathogenic bacteria that ultimately cause fatal sepsis. This scenario, in which ora attacks and buffalo deaths are temporally, but not causally, connected, compounded by the observation of oras scavenging on the carcasses of dead buffalo, likely lead to the “folk toxicology” explanation of V. komodoensis using bacteria as a weapon.

The (un)natural history of Varanus komodoensis and Bubalus bubalis. These two animals share a habitat only because of the recent (< 300 years) introduction of B. bubalis onto the islands by Dutch settlers. Consequently, (A) B. bubalis does not re…

The (un)natural history of Varanus komodoensis and Bubalus bubalis. These two animals share a habitat only because of the recent (< 300 years) introduction of B. bubalis onto the islands by Dutch settlers. Consequently, (A) B. bubalis does not recognize V. komodoensis as a natural predator, while V. komodoensis will experimentally attack any animal. (B) B. bubalis always escape but sometimes with deep wounds to the hindquarters. (C) Upon seeking refuge in the tiny rocky watering holes that are the only water source on the small islands, the wounds become infected because of the high concentrations of fecal matter. (D, E) If death occurs, multiple V. komodoensis will feed on the fresh carcass, using their powerful necks and forelegs to remove large chunks of meat. (F) Only once the adults have finished will the smaller V. komodoensis feed on the remains. (Photos A, D, E: Chris Kugelman; B, C: Bryan G. Fry; F: Gembong Riyadi Nurrasa.). From our book Venomous Reptiles and their toxins.