Without doubt, one of the coolest living animals on the planet is the Komodo dragon Varanus komodoensis, a giant flesh-eating lizard that kills water buffalo, eats children, harbours noxious oral bacteria and is impervious to bullets (ok, I made that last bit up)…
Unknown to western science until 1912 (when it was ‘discovered’ by J. K. H. van Steyn van Hensbroek, and described in the same year by P. A. Ouwens), it reaches a maximum authenticated length of 3.5 m and can weigh about 250 kg (Steel 1996). In contrast to most other monitors, its legs and tail become proportionally short and stocky as it gets larger. As a juvenile it is an excellent climber; as an adult it can dig burrows, locate carcasses that are more than 10 km away, swim from island to island, and kill a water buffalo that weighs about 600 kg. Using teeth and claws, it disembowels, hamstrings and slashes its prey, and it may also shake prey to break the neck. Serrations on the posterior margins of the recurved teeth* end up housing rotting meat and an interesting assortment of over 50 bacteria that can cause septicaemia and death (despite claims that dragons are ‘infector killers’ it still seems most likely that any effects these bacteria have on prey are accidental) [see comments section for discussion of recently discovered venomosity].
* Anterior teeth are unserrated on both anterior and posterior carinae.
While adult dragons today mostly eat mammals that have been introduced to Komodo, Rintja, Flores and the adjacent islands, fossils show that dragons previously lived alongside dwarf elephants (both Elephas and Stegodon), and it has even been argued that the dragon might be a specialised macropredatory giant that evolved to kill these (now extinct) endemic mammals (Diamond 1987). However, there were plenty of other small and mid-sized mammals that inhabited the same islands at the same time so ‘their diet was possibly more varied than just pygmy elephant’ (Mitchell 1987). Furthermore, the Komodo dragon almost certainly isn’t an example of island giantism: instead it apparently retains the large body size of a mainland ancestor (Gould & MacFadden 2004).
Dragons can be pugnacious beasts that might maim one another during combat; they also have cannibalistic tendencies. However, they also engage in appeasement behaviour, they tame quickly and appear to bond with humans, and ‘it is the opinion of many keepers that dragons may be among or the most intelligent of reptiles’ (Walsh et al. 2004, p. 12). As demonstrated by the awesome photos shown here, they can put their differences aside on at least some occasions, and it is well documented (although poorly known) that they will form ‘feeding scrums’ when attracted to a large carcass (Auffenberg 1981).
Finally, the wild population of several thousand individuals is generally regarded as relatively stable: excepting Flores, the range of V. komodoensis was declared Komodo National Park in 1980. Some of the populations that occur on various of the smaller islands (such as Gili Motang and Flores) are regarded as particularly vulnerable to habitat loss and other threats, such as slash and burn farming (Ciofi et al. 1999).
Ok, so this was meant to be a picture of the day submission, but I suppose I got carried away. The pictures used here were supplied by Tim Isles (thanks Tim), but they’ve been used on the internet before: we lack data on who took the photographs and would be interested to get any news on this. Must revisit this species again. I previously wrote about play behaviour in Komodo dragons at ver 1, here. In fact I’m feeling a deficit of articles on big lizards in general. Great, now I have guilt. And didn’t I say I wasn’t going to publish anything today? Oh well, I’m sure you can all forgive me.
Refs – -
Auffenberg, W. 1981. The Behavioral Ecology of the Komodo Dragon. University of Florida Press, Gainesville.
Ciofi, C., Beaumont, M. A., Swingland, I. R. & Bruford, M. W. 1999. Genetic divergence and units for conservation in the Komodo dragon Varanus komodoensis. Proceedings of the Royal Society of London B 266, 2269-2274.
Diamond, J. 1987. Did Komodo dragons evolve to eat pygmy elephants? Nature 326, 832.
Gould, G. C. & MacFadden, B. J. 2004. Gigantism, dwarfism, and Cope’s rule: “nothing in evolution makes sense without a phylogeny”. Bulletin of the American Museum of Natural History 285, 219-237.
Mitchell, P. B. 1987. Here be Komodo dragons. Nature 329, 111.
Steel, R. 1996. Living Dragons. Blandford, London.
Walsh, T., Visser, G. & Lewis, R. 2004. Komodo Dragon Husbandry Manual of the AZA/SSP & EAZA/EEP: accessed online, 2005, at http://www.varanusweb.com/species_content/Kd-HDL-2004.pdf.