Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Monitor Lizards Varanus sp.

A brief species overview for the prospective first-time monitor buyer...

©1993 Melissa Kaplan


This is one of the earliest reptile articles I wrote and, like most of my articles then and later, was in response to the too many people who had decided that they wanted something "cooler", more impressive (i.e., bigger, scarier to others, less frequently seen in the pet trade) lizards. Most of the individuals seeking "cooler" lizards seemed to want something bigger than green iguanas and less common (and bigger) than savanna monitors. Thus there were all sorts of people who had never owned a lizard before, rushing out and buying Nile and water monitors without regard for the fact that they knew little to nothing about them other than their common name. Since the following is from a message board post (Prodigy, AOL, rec.pets.herp) it is a bit less structured than my more formal articles.

 To start out, you might want to stay away from the "giant" monitors, especially the Nile (V. niloticus niloticus) and (V. n. ornatus), reaching 7-10', are very wary and aggressive, requiring lots of time and respect. Most Nile owners end up trying to get rid of them by the time they reach 5 feet. The Salvador or Crocodile monitor (V. salvadorii), second in size only to the Komodo dragon [9+'], is largely arboreal, eats birds and eggs [not store-bought infertile eggs which cause biotin deficiencies). The Water or Asian Water Monitor (V. salvator, similar in appearance to the Nile), grows to 7 feet, and is highly aquatic.

Beware of stores mismarking the Salvador and the Water monitors! Due to the similarity in Latin name, the Water monitors are often called Salvadors, and vice versa. Aside from the fact that these monitors need an extraordinary amount of room (to move around in, to swim in, and for you to be able to get in and clean up) and that they grow quickly (many owners are surprised at just how fast the Nile reaches 5 feet), they have crushingly powerful jaws and bites can result in your getting to know the emergency room staff and a plastic surgeon quite well.

Many people have been turning to the above monitors to get something "different" from all the people buying Savanna monitors, just like the popularity of Savannas can be tied to all the people who wanted to be different and not get a green iguana. While that's great for all the green iguanas, it isn't necessarily great for the monitors if their new owners are as unprepared for the realities of their care and keeping in captivity as are too many iguana owners (a situation that, sadly, has not, from the vantage point of this 2002 review, changed very much).

Other questionable monitors include the Mangrove (V. indicus), 5', semi-aquatic, eats vertebrates and crabs; "skittish" and rarely fully tameable as all specimens are wild-caught adults; they spend most of their time hiding, frequently defecating when handled, and are very powerful and very fast.

Savannas (V. exanthematicus exanthematicus) and white-throated (V. albigularis spp.), 4', dry but needs pool to soak, temps 85-90 F/day, 75-80 F/night. Dumeril's monitors (sometimes called the gray rough-neck monitor in the trade rather than Dumeril's monitor, V. dumerilii heterophilis and V. d. dumerilli), 4', arboreal (thick strong branches climbed with their very long claws and strong toes) and loves to soak (need a tub big enough to soak), with tropical requirements (humid, temps 85-95 F/day, 74 F/night). These two monitors can become--with work!--quite tame. The Savannas are widely available and generally cost somewhere under $100. Dumeril's were becoming more difficult to obtain a couple of years ago (it may have changed now) and so are quite a bit more expensive.

The Green Tree Monitor (V. prasinus) reaches 2.5 feet, is arboreal, spending most of its time in the high canopy in the vine, monsoon, palm, rain and and mangrove forests. In other words: they like it humid! Prehensile-tailed, feed mostly on arthropods, lizards, small birds, and need lots of room despite its relatively small size. Probably not a lizard for beginners, especially if one has not checked out local availability of food for them, and the amount of room they need is much more than one would think, space suited for an arboreal lizard (lots of height).

The Black Rough-Necked Monitor (V. rudicollis) gets to 4', is arboreal, likes to soak, is social [two may be better than one], can be tamed pretty well. Like all tree monitors, they have very long claws. Most wild-caught adults do not survive in captivity - the stress and parasite load proves too much for them. Younger specimens often do well, especially when treated immediately for parasites and protozoans.

That being said, what you need to know is there there is very little breeding of monitors being done outside of zoos, and they aren't real active about it. (Many people buy the large monitors claiming that they are going to breed them...despite the fact that they live in small houses or apartments and the only successful breeding of Niles, for example, took place in an enclosure 18 ft x 20 ft!) My favorite are college kids who are going to breed them in their dorm rooms.

Assume that any monitor you buy from a pet store or through an ad in the paper, or from a herp dealer will be a wild caught one. This means you need to choose carefully - both the type you get and the actual lizard you select. Have a reptile vet -- an experienced reptile vet -- lined up ahead of time and, for some of species, sources of food. While many will cheerfully eat rodents in captivity, many of the smaller monitors' wild diets consist heavily on invertebrates, lizards, frogs, birds and eggs, and they may require such in captivity or be difficult to convert. And, speaking from experience, it is very difficult to open a monitor's mouth to stick a feeding tube down it when it doesn't want to open its mouth!

Remember that tame is as tame does. I was boarding a lovely 4', 10 lb Savanna - totally tame, a real sweetie. I was holding him one day (like a baby or an iguana, head up at my left shoulder, arms cradling and supporting his body) when I felt him nosing around my neck. Just as I reached up to feel what he was doing, he grabbed me by the throat. Fortunately, he was apparently just as confused about having done that as I was, as, had he wanted to, he could easily have ripped my neck apart. As it was, I remained as still as possible, moving only to move with him as he twisted and bit harder. I was also fortunate in that I was not alone when this happened (as, had I been on my own, with two arms supporting the monitor, it would have been interesting trying to get to the bottle of rum or vinegar (used to get him to let go) and that the person I was with was an experienced herper who didn't freak out too much when this happened. As soon as he was disconnected from my neck, he was just as placid as before. My neck did not bleed much at all (though my chin did, being sliced by his teeth as he flung his head away from my neck when the vinegar was applied), but I had a brilliant red circle of teeth marks visible on my throat for several days, disappearing only after a week or so.

Check out and join one or more varanid specialty and other herp societies, and join related email discussion lists.

Michael Balsai has written books and articles on monitors; they are definitely worth checking out and acquiring if you are serious about monitors. Giant Lizards, by Robert Sprackland and published by TFH which includes descriptions and some excellent photographs of the monitor species is another good book about monitors. Be sure to also check out Daniel Bennett's monitor site (and books) as well.

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