Naïve large Australian varanid lizards have recently been shown to suffer a massive increase in mortality (> 95%) when attempting to feed on this toxic amphibian. The high susceptibility of Australian varanids to toad toxin is caused by minor mutations in the sodium-potassium-ATPase enzyme.
In the present study we show that Komodo dragons (Varanus komodoensis) have similar mutations within this enzyme as observed in Australian varanids demonstrating that dragons are extremely susceptible to toad toxin. During the last decade the black-spined toad (Bufo melanostictus) has been able to invade areas close to the five toad-free islands constituting the habitat of Komodo dragons. An invasion of highly toxic black-spined toads into dragon habitats may therefore cause similar dramatic increase in dragon mortality as recorded in Australian varanids imperiling the long-term survival of this giant and iconic lizard.
Ujvari et al. 2015 Pacific Conservation Biology 20: 363-365.