There seem to be two concurrent threads happening here! 1. captive monitors and carrion - I happen to agree with Dragoness on this one. Wild monitors eat amazingly rancid stuff, but I believe they have to 'inoculate' themselves gradually. I think if a captive were to try eating something truly rancid without ever having been exposed to it before it would get bloated with gas and would end up regurgitating it. It would knock it around for a while and the monitor could end up being quite unwell. The next time it tried eating rancid carrion it will probably have better luck keeping it down. This is anecdotal and based on a small number of observations, though, so I wouldn’t take it as gospel. 2. Komodos and venom/bacteria – this one is quite complicated, I think, and I don’t think there are any pat answers. I used to be okay with the idea that the dragons used bacteria to kill large mammals slowly, even if it meant other dragons benefitting from the animal’s death. Then Bryan mentioned the venom found in monitors (not just the dragons) and it made sense that the animals die faster than bacteria alone could account for. Then I visited the islands myself last year. Of the many things that made me think twice, one was seeing two buffalo still alive after being bitten by a dragon. One of the buffalo had been bitten several days earlier (the ranger had seen the bite occur and we visited the same buffalo twice) and the other we had no information on. The latter buffalo was clearly in distress and probably not going to make it (see photo below), but the bite on the other was starting to heal over (although it still had a swelling around the bite, indicating infection). That certainly doesn’t suggest strong venom. A few things to consider: 1. Komodo dragons have an incredibly nasty bite, with or without venom and/or bacteria. They’re a big lizard with sharp teeth, so most animals copping a good bite will stand a good chance of bleeding to death anyway. If the venom helps this process by accelerating the bleeding and slowing the coagulation, this would be beneficial to the dragons. 2. Other monitors have a similar venom (according to Bryan’s earlier papers), not just the closely related lace monitor but even more distantly related species, none of which attacks large prey in the way the dragons do. This would suggest that the effect of the venom in helping large mammals bleed to death would be convenient, but not why it originally evolved. Something that sends an animal into shock may still be beneficial, though, even if it is a small prey item but a professional herpetologist (Sam Sweet) suggested in a similar thread elsewhere that it may well have evolved in small monitors first as a deterrent to predators – most people working with monitors will tell you that the bite of small species hurts a lot more than it should for their size. This would put off enough predators to be of benefit. 3. There is some doubt as to which of the current prey animals of the dragons are truly native and which have been brought to the islands by man at some point in the past. Although there are water buffalo, wild boar and Timor deer native to that general region of Indonesia, it’s thought that the buffalo weren’t on the smaller, isolated islands (such as Komodo itself) until locals brought them there. Buffalo are the animals most often mentioned in discussions on dragons and venom and/or bacteria, because their size suggests that dragons would need help getting them down. Pigs and deer are probably native, but both of those are small enough to be incapacitated by a dragon bite – with or without venom and/or bacteria. The venom and/or bacteria may help matters, of course, particularly the venom if it caused immediate shock. So, what all of this says in a long-winded way is that monitors may have evolved venom so that smaller ones could defend themselves but large dragons may use this to their benefit by helping to knock down large prey items faster, whether they need it or not. Bacteria also helps if the prey doesn't die right away. …which probably doesn’t answer anything anyway I do have a photo of a buffalo having a bad day as a result of a dragon bite, though!