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

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

 

Browsing the pages of Herpetologica and other journals over the years, I several times came across field studies indicating that certain populations of savannah monitors consumed diets composed entirely of invertebrates.  In certain seasons, the lizards gorged on either locusts or land snails exclusively for months on end.  When some captives fed largely upon rodents showed evidence of kidney and liver damage and intestinal impactions, articles in popular magazines began calling for insect-based diets.

Canned Diets

Savannah monitors may approach 5 feet in length, and thus an insect-based diet is difficult to arrange…thousands would be needed weekly in some cases.  Zoo Med’s Canned Tegu and Monitor Diet provides a handy solution.  Formulated with these lizards in mind, it is readily accepted by most individuals.

After reading the aforementioned articles, I took a moderate position as regarded the savannah monitors under my care in public collections, using canned food as 60-75% of the diet.  I supplemented the food of adults

once weekly with vitamin/mineral powder  and that of juveniles 3-4 times weekly.

Invertebrate and Vertebrate Food Items

The easiest way to supplement canned food without using mice is to establish a breeding colony of Madagascar hissing roaches (even the well-armored adults are readily accepted) and nightcrawlers.  Crayfish, if available to you, are a great monitor food.  Other useful food items are land snails (available in seafood markets), tomato hornworms, hard boiled eggs (in moderation, i.e. once monthly) and canned grasshoppers , silkworms  and snailsPink and fuzzy mice (these are preferable to adult mice and rats) may be offered every 10-14 days.

My Observations of Wild Black and White Tegus

My observations of black and white tegus in Venezuela leads me to believe that, at least in llanos habitat, these lizards consume far more large insects, turtle eggs and frogs than rodents.  Mammals are taken when available, mainly as carrion or unearthed rodent nests.

I have kept tegus for lengthy periods on rodent-based diets but now counsel more variety…I suggest feeding as described above, but with canned food comprising a smaller portion (i.e. 25-50%) of the diet, and rodents, preferably pink and fuzzy mice, being offered once weekly.  If your tegu will accept whole fish (i.e. large shiners), use these in place of mice.

An interesting article on savannah monitor natural history and diet in the wild is posted at http://www.mampam.com/index.php?option=com_content&task=view&id=36&Itemid=76

22 comments

  1. avatar

    yes i have fed this food to my savannah monitor, he used to eat it readily a long as i wasnt watching, now when i give it to him he doesnt eat it but instead spits it out, i still try because i want his diet to be more varried but since i started giving him fuzzies and hoppers he really only wants whole prey, he eats frozen thawed mice, live crickets and earthworms and if he will eat it this canned food. he refuses all other types of monitor food, this seems to be the best but i feel he thinks it is too boring and too mushy. if they made a bunch of big solid cubes they would like them more. i liked this topic and the connected site, i have had a hard time finding information like that and i do want to know where he comes from and what wild savs do and live. Thanks!

    • avatar

      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.

  2. avatar

    i have a golden tegu got him when he was older and agressive tale has been broken and he has hardley any nales on his feet. try to make him tame by holding once a day but really makes him angry i want him or hre dont know to be able to come out of its cage have any sugestions

    • avatar

      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.

  3. avatar

    my golden tegu was given to me at an auction a few months ago. i own a b/w arg. tegu that i have had for a little over a year. he is great. but the new one is not eating. iv tried everything. please help.

    • avatar

      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.

  4. avatar

    is it ok to feed my savannha moitor bullfrogs

    • avatar

      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.

  5. avatar

    hi, i just bought a juvenile savannah monitor a couple weeks ago and all he do is sleep, is that common? ..it seem like he eats when he wants to, just like today i tried offering him a pinky and he didnt take it, is that common?” I gave him a live pinky last week and he ate it, this week i gave him a thawed one and he regurgitated it..do u think he rather take live than frozen/thawed?

    • avatar

      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

  6. avatar

    Hey Mr. Indiviglio,

    I’ve been keeping reptiles/fish/amphibians and various aquatic predators my whole life, but this is the first time I’ve tried a large, carnivorous lizard.

    I just got an 8 inch Savannah monitor last saturday and I have a few questions to ask. The first and most important is how will I be able to tame him to a handleable level so he doesn’t become agressive as an adult? Right now he either retreats or tolerates me when I change his water/approach his tank, I haven’t handled him yet. Also, he doesn’t seem intrested in mealworms, I’ve tried several times and they just end up escaping into the cage, and how will I be able to integrate canned food (like zoo med’s monitor food) into his diet? In the long haul it would be the cheapest alternative to rodents. And how often should I be feeding him/what would be other food items I could give? I do it everyday right now. What substrates would be good? I’m using paper towels right now, but I do have a case of aspen snake bedding that I got along with him and, I’m also looking into Exo-Terra’s desert sand, coco husk and other subtrates.
    And last but not least, all he seems to do is loaf/bask/sleep, he will sometimes roam around or look for a way out but the majority of the time he just lays there. I use Exo-Terra’s Solar Glo lamp for lighting and heating during the day, the cool side is around 85-90 degrees while the basking side gets around 100. The temp at night is around 80, maybe a few less.

    I think that’s about all I could think of right now. Many thanks, from one herper to another!

    • avatar

      Hi Alex,

      Healthy monitors tend to eat whenever food appears, but as yours is new it is likely adjusting to its new surroundings. A hiding spot/cave is impt to its welfare, as is a suitably large cage. A 55 gallon tank would be ideal for that size animal, but he will outgrow it very quickly…you’ll likely need a custom made cage in time. Best not to handle until it has settled in and adjusted. personalities vary, but all need routine handling in order to remain calm around people. They cannot be tamed in the manner of a dog or cat, however…they can inflict severe injuries, and may bite in response to things we cannot hear/smell/sense. so caution must always be exercised.

      Cage liners or carpeting is preferable to wood chips, and esp to sand and coco husk. These can be swallowed and may also stick to the cloaca during defecation.

      Despite the studies quoted in this article (re inverts as food), many folks have done fine using pinkies and fuzzies as a major part of the diet. Earthworms, crickets roaches and canned insects (see article for link) should also be offered. You can add a favorite food into the canned monitor food once it begins feeding. keeping the animal hungry for a few days will also encourage it to take canned food. You can feed 3-4X week, depending on type of food given.

      Lying about is what reptiles do best! It is in their interest to conserve energy. Monitors, being ever-hungry, sometime move about more often, but even they have a tendency to become obese and develop related health probs in captivity. A large cage, esp an outdoor pen, that can be seeded with live food, will encourage activity. However, if it lies “flat out” on the belly, w/o any movement, doesn;t bask and does not begin feeding, a vet exam is in order. please let me know if you need help in locating a nearby reptile vet.

      Be sure to use supplements on most meals, other than rodents; repticalcium with D3 and retivite work well.

      Please see this article for general monitor info and let me know if you have further questions.

      Enjoy and please keep me posted, Best, Fran k

  7. avatar

    I’m pretty well off and prepared then. He seems to just be basking normally, as opposed to being lethargic.

    Only one concern is left: what level of humidity would be needed? Also, do you know of any sites that sell Dubia or Malagassy hissers? The only good one I can find is backwaterreptiles.com since they offer free shipping.

    Oh, and I have noticed that he seems to be a heavy sleeper, I was doing maintainance (moving decor/installing lights) and he didn’t even seem to notice. He also seems to toss around and move while he sleeps, like we would while sleeping (possibly dreaming?) and he uses a rock near his hide opening as a pillow of sorts, always the same one and in the same position.

    • avatar

      Hi Alex,

      They are adapted to dry environments, so humidity not a concern…damp conditions can lead to fungal and other problems. A water bowl large enough for soaking is sufficient. Fill to a point where it will not overflow when the lizard enters.

      It’s common for them to return to a specific site to sleep; they are territorial as well, which may be one of the reasons that shipping, changing habitats throws them off for a time.

      I haven’t dealt with any specific suppliers lately; best to keep an eye on the Kingsnake.com feeder ads; I noticed hornworms were listed there today; they are a great source of dietary variety for larger herps.

      Best, Frank

  8. avatar

    I’ve now gotten him to eat Zoo Med’s canned monitor food. I started by tempting him with crickets and tricked him to strike at the food instead of the bugs. The only problem is that it sticks to his jaws when he tries to swallow and it flies out of his mouth when he shakes his head. Any tips on how to handle this phenomenon?

    Cheers,
    Alex

    • avatar

      Hi Alex,

      You might try rolling it into bite-sized balls that can swallowed easily. Rolling the balls in some bread crumbs may dry and hold the food together, making it less likely to stick or get tossed around. However, food remaining along the jaw line, etc. is not ideal, so you may need to re-consider if this does not help.

      Best, Frank

  9. avatar

    Hi Frank,
    Sorry I have not aswered your last email, I will do, hopefully today.
    There seemsd tobe large discussions on the use of UV for Savanna monitors, often quoted as its up to the owner if they use it or not.
    To me this does not seem a suffecient answer, surely if they come from hot and sunny climate, then they should have some level of UV.
    i have tried to look for recent research, but have been a bit busy re the rescues, can you shed any light on this exsuse the pun.
    Also should the uv if needed be uvb or just uv.
    Hope you can help ,I will want to post answers to this on my rescue page if thats alright.
    Thank you Frank.
    Take care,
    Bella

    • avatar

      Hi Bella,

      Nice to hear from you.

      Savanna Monitors should be provided UVB; the critical range is 290-315 nanometers, this is not well-established and is provided by bulbs made by reliable companies. Florescent bulbs should be positoned within 6-12 inches of the baqsking site; mercury vapor bulbs broadcast over a greater distance. Please see Part I and Part II of this article, and let me know if you need further info.

      UVA (320-400 nm) may encourage natural behaviors and breeding, but is not critical. Many bulb manufacturer’s are now including a UVA component in UVB bulbs. Please see Part I and Part II of this article for details.

      Certain heliothermic (sun-basking) lizards and turtles that normally metabolize D3 in the skin, when exposed to UVB, can utilize dietary D3 if it is provided in certain amounts and forms; savannahs may be among these, but we do not have any specifics as to details of feeding them properly in the absence of UVB; given the ready availability of uvB LAMPS AND THEIR NATURAL HISTORY, uvb should be [provided to all captives.

      Yes, please feel free to post the answer on your site; thanks for the interest. please include a link back to the original article, and the links that I’ve added within this response. I’ll be happy to answer any questions your readers may post.

      Sorry for the delay in responding to Facebook comments; I’ll catch up soon.

      Best regards, Frank

  10. avatar

    just a quick question you say in one of your replys that savannah monitors are used to dry conditions this is wrong they need humidity of above 60% also they need to dig and burrow so need a bedding material of dirt at least 2ft, or is this information wrong also canned food is this true that they are ok for this type of animal as most of my research says other wise

    • avatar

      Hello,

      Canned foods can be used as part of the diet as described in the article; various populations from different parts of the range have adapted to different foods; knowing the origin of your animal’s ancestors would be very useful, but this is difficult for most pet owners to determine. In common with many arid adapted animals, this species does spend time in humid burrows,. In captivity, their needs may be met by providing a large water bowl (for soaking), misting daily; shelters are required, but the ability to create burrows, while desirable, is not essential. Best regards, Frank

  11. avatar

    Hi my name is Justin Myatt.

    I just wanted to tell you I loved reading your blog and admire your passion in caring for reptiles. I have had a collection of reptiles for the last 5 years that has grown to almost 200 heads. I also am working with a very special group of bearded dragons I have amassed. My selective breeding goal is to prove out the paradox gean that has appeared in the last few years. This year I produced 2 purple paradox silky dragons and be live it to be a result of pairing two codom leatherbacks that are either hett. Hyposmellenistic or hett. Translucent, both the lizards have been proven out to be codom for opposite their hett.s so…. Anyway I was just ranting on. I would love to speak with someone that has had the opportunity to field herp. With larglizards. I have a collection of monitors and one prized Argentin red (massive. Female) tagu. Feel free to contact me I also have a huge passion with the anacondas. Have owned 3 currently working with constrictors…

About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.

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