Diet

All monitors are carnivorous, which means they all eat meat or insects. Only Varanus olivacaeus and the newly described V. mabitang, which both live on different Philippine Islands also take fruit and leaves (AUFFENBERG 1988, GAULKE & CURIO 2001). Insects, spiders, crayfish, fish, amphibians, reptiles, eggs, birds and mammals are the major part of the standard diet of all monitors, depending on the size of the animals. In the wild you can frequently see, that monitors, particularly V. niloticus, V. gouldii, and V. panoptes track clutches of eggs of other monitor species or crocodiles and take the eggs out of the nest (BAYLESS 1992c, LENZ 1995). They are not particularly selective in food. They sometimes also do not avoid to overpower smaller specimen of the same species (SHINE 1986). Since the sizes of the different species vary, the food spectrum is very variable too. In the wild members of the smaller species mainly feed on insects and smaller reptiles, which they can overpower. So V. komodoensis from Komodo Island not only feed on pigs, which occur on this island, but also takes red deer and wild domestic animals as well as humans become victim of monitor attacks. Numerous stomach examinations to free living monitors give information, which preferential food is taken by the single specimen (JAMES et al. 1992, LOSOS & GREENE 1988, PIANKA 1968, 1969a, b, 1970a, b, c, 1982, SPRACKLAND 1993b, ZIEGLER & BÖHME 1996, GAULKE & CURIO 2001). It is not possible to offer this food variety in captivity. As food items for the smaller species we could offer crickets, house crickets, grass hoppers, locusts, cockroaches and larvae of the Giant Mealworm. Freshly born mice occasionally offered enlarge the menu. Since the food however contains a balanced mixture on vitamins, minerals and fibre in the wild, it is absolutely necessary to adapt these conditions for the animals in captivity as close as possible. So it is good to dust all insects with a vitamin mineral mixture, e.g. Nekton MSA® or Korvimin ZVT®. But do not offer too much food, because especially crickets and cockroaches could hide within the decoration and the monitors could not reach them anymore. Night active, the insects could also become a thread for the reptiles. Till now, it is not reported, that crickets have attack healthy monitors, but the risk is there, especially when you raise offspring. With bigger monitors feeding of insects is not really possible. Mice and occasionally rats and chicks are the better food. Feeding chicks can cause a minor problem, because excrement is very thin and smells unpleasant. You will have to clean the enclosure immediately for hygienic reasons after this. The dead animals mentioned above should be enriched with vitamins and minerals too. Now you can inject liquid preparations, e.g. Tricrescovit® or Multimulsin®, in the food animal with a syringe and cannula. You should inject the dead mouse or the dead rat about 0.5 to 1 ml at Tricrescovit® every second to third feeding. You can give Multimulsin® in the same dosage. No visible side effects appeared at these vitamin diet at long-standing attitude till now. It is not advisable to feed the monitors with canned dog- or cat-food, because this food only contains too much protein, but it is very low in minerals and fibre.