Feeding Captive Savannah Monitors (Varanus exanthematicus) and Black and White Tegus (Tupinambis merianae): Zoo Med’s Canned Tegu and Monitor Diet

Hello, Frank Indiviglio here. Thanks for your interest in our blog and for your feedback on the article…much appreciated.

Savannah monitors very often develop food preferences in captivity…this may be linked to their behavior in the wild. I have read field reports citing animals found with “thousands” of locusts or snails in their stomachs, and noting that these items form the entire diet for months at a time. So, when they encounter something that tastes good and is available, they stay with it.

You might try mixing the canned food with your lizard’s preferred food – try to arrange it in such a way that the animal must eat both in order to get at its favorites. Try spreading the canned diet on mice or mixing live earthworms or super meal worms into the food. Don’t be afraid to keep it a bit hungry – savannahs are great at storing food and he/she likely has plenty of reserves.

It’s good to use pinkies and fuzzies as opposed to adult mice for most of the rodent portion of the diet, and earthworms are a very good food item. Other large food items that can be used to increase dietary variety are canned grasshoppers, silkworms and snails. These and some hard boiled egg can also be mixed into the canned diet. If available at a local seafood market, land snails are usually taken, and they relish roaches and crayfishes as well.

As concerns their habits in the wild, such varies greatly by location. The name “savannah” sometimes misleads folks into picturing these magnificent lizards as limited to East Africa’s grasslands. But in actuality savannah monitors occupy a huge swath of north and central Africa, being found from Mauritania clear across the entire continent to Sudan and south to the Democratic Republic of Congo and Kenya. If you take a look at a map of Africa, it will be easy to imagine that within this huge range they have adapted to a variety of diets, habitats and conditions.

Monitors are not the only reptiles that tend to become “picky” eaters. One adult anaconda I cared for at the Bronx Zoo would eat wild-caught rats but rejected those raised commercially for reptile food – this despite the fact that both are the same species, Rattus norvegicus. Another anaconda took only muskrats, which had to trap for her…eventually I weaned her onto muskrat-scented lab rats (muskrats are among my favorite local creatures, so I was relieved when the snake became more “reasonable” in her demands!).

Please keep me posted, and let me know if you would like further information.

Best regards, Frank Indiviglio.

Hello Jesse, Frank Indiviglio here.

Thanks for your interest in our blog.

Unfortunately, tegus are often quite problematical in captivity. Although close contact often habituates animals to people, in tegus, especially aggressive adults, it usually does quite the opposite – increases their stress level and renders them even more defensive. I would not suggest trying to handle it any further.

A male I cared for in the Bronx Zoo attacked keepers even after 14 years in captivity…and his exhibit measured 20 feet by 6 feet, more than enough space to allow him to avoid us. A wild one I encountered in Venezuela (please see my article Notes from the Field) attacked despite having literally miles of grassland over which to escape.

I’ve watched tegus in the wild – they cover an incredible amount of ground while foraging each day, and seem unable to settle into even quite spacious cages. I suggest you treat yours as an animal to observe rather than a pet to handle. I doubt that attempts to calm it thorough contact will be useful. Give it as large an enclosure as possible – you’ll need a custom made cage or something along the lines of an outdoor aviary to properly house the animal; outdoor access is ideal By allowing the lizard to stay well away from you when you enter to feed, you can decrease its stress level and reduce aggressive behavior. If space is a problem, you might wish to get the animal into a situation where it can be give the room it needs. Long term stress (expressed as aggression in your tegu) will eventually weaken its immune system and lead to its early demise.

Sorry I could not provide a more optimistic answer, but this really is the best advice in this case.

Please keep me posted and be in touch if you need further information,

Best regards, Frank Indiviglio.

Hello Stacey, Frank Indiviglio here.

Thanks for your interest in our blog.

Unfortunately, I’ll need a bit more information before I can offer any advice. Please let me know the animal’s size, the size and physical layout of the cage, any history you might have (wild caught/captive bred, past diet, etc.), the ambient and basking temperature, UVB source, foods offered etc.

However, if the animal has not fed for several months, you should have it examined by a veterinarian, as it may be ill, or have an intestinal blockage or heavy parasite load.

Please write back with any information you might have and I’ll be happy to lend a hand.

Best regards, Frank Indiviglio.

Hello Mark, Frank Indiviglio here.

Thanks for your interest in our blog. It’s not a good idea to feed bullfrogs to monitors – most frogs have skin toxins, and animals not native to the frog’s range have no instinctive avoidance (in Australia, monitor populations are declining due to deaths resulting from consumption of introduced marine toads). Bullfrogs are not known to be especially toxic, but I have seen tiger salamanders release small ones and then rub their mouths on the substrate, as if in distress.

A potentially worse problem is the possibility that various bacteria and other micro-organisms that live in the bullfrog and cause no problems to healthy individuals could be deadly to an animal from another continent, such as the savannah monitor.

Good luck and please keep me posted.

Best regards, Frank Indiviglio.

Hello Jamar, Frank Indiviglio here.

Thanks for your interest in our blog. It is not usually for the animal to sleep continually; please send me some details as to basking temperature, ambient temperature, UVB light source and so on; low temperatures can cause the lizard to become inactive, and also to have trouble digesting food. Live/frozen is not critical. As long as the food is thawed properly, there is no need for live pinkies.

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio