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Monitor lizards comprise about 40+ different species of the Genus Varanus of the family Varanidae. These really small to the larget of all lizards are all old world lizards coming from Africa through Southeast Asia though the Indonesian archipeligoes and the continent of Australia. In some of their ranges monitor lizards are the top predator - having no mammal predators bigger that it to compete with, and in some areas the monitors are small enough to occupy specific niches and are fodder for many other predators. Monitor lizards howevere generally embody the form and shape of what can by many be considered a 'true lizard'. Possessing powerful limbs, an elongated body, and a head held high these lizards represent the dinosaur age in the current millenium. Monitors have been kept as pets for many many years, yet only recently they have acquired a status denoting them as the 'commonly' kept reptile, where this had never before occured. When keeping these monitors in captivity, the need for the most up to date information about housing, feeding, handling and medicinal aspects is very important. In this web page we will attempt to provide as much current information on as many of the species that are available to the pet trade - and on some that are not. This information is designed to educate the monitor aficianado to better understand the monitor from a scientific stand point based on anatomical and physiolgical points of views and in relation to field studies done to better under stand the speices in question. With this information in hand you will be better able to provide properly for monitors in captivity. Some of the more common species such as the Savannah, Nile, Water, White Throat, Dumerill's and Tree monitors are easily covered. Others like the Crocodile, Argus, Spiny Tailed, Timor, Black Roughnecked and others are generally difficult to find information on. This web page is designed to combat that. There will be information on all these species and it will be updated as frequently as possible to allow for new inroads being laid down every day. With the internet as the back bone of this information, this should allow for constant and acurate updates to the information you will need to properly care for these species. For the less common, rarely seen monitors, information will be gleaned from accounts of thier wild and captive husbandry from thier countries or origin, zoo records, taxon management accounts and otherwise to better able people to understand them and thus care for them correctly. This information is presented 'in general' meaning it applies generally to the most monitors. Most monitors can be broken up into two distinct groups by way of housing.There are the dry and arid types, near wetness types and aboreal monitor types. The savannah, white throat, spiny tailed, Argus, Timor and Gould's type monitors all generally live in or around savannahs, dry rocky outcroppings and forest fringes, where they either frequent crevices or burrows for shelter. The 'near water types' like the water, roughnecked, mangrove, nile, and Dumerill's monitors generally live very near to bodies of water. Exisiting eiher at the edge of forests, in the forest or around or near bodies of water running through forests. The aboreal species such as the crocodile, green tree and black tree monitors all inhabit upland forests and are known to be semi if not completely aboreal. In grouping these monitors it is easy to provide general guidelines as to how to house them in captivity. These groups will be explained spearetly. Remeber it is always important to understand as much about the monitor you have or intend to have so that you can provide for it as best as possible. For the species that comonly inhabit dry, arid rock out croppings, savannah and steppe type areas the cage does not in fact have to be dry - yet moisture can be a bit of a problem also. A cage that is to dry can cause dehydration in a monitor, so there are things of course to remember when designing cages for these monitors. By way of a dry cage, it normally means no pools of water and very little humidity. The choice of substrates can be a key factor here. The most success ever attributed to a substrate is with aspen wood particles. These loosely packed cellulose products tend to absorb moisture readily and dries out fecal matter this in turn prevents odor, mold, mildew and bacteria - it also happens to keep the cage relatively dry. Another suitable substrates - yet problematic in captivity is sand or other finely ground mediums. Sand tends to get ingested by accident and can cause intestial impactions. It is known that some animals ingest rocks to aid in digestion by way of a gastrolith, yet on necropsy, I have found most rock or sand materials to be a detriment. Aspen, if ingested tends to pass the best. Products to stay away from are corn cob, astro turf, gravel, cedar or pine bedding and any of the hardwood beddings that are on the market as well as most of the bark based wood products. Cypress mulch is another product that can be used if kept dry - otherwise it tends to hold moisture very readily. Species that commonly inhabit the near water areas such as nile, water, black roughneck, Dumerill's and mangrove monitors can also utilize aspen as an appropriate substrate. The reason for this is that same as for desert species - it dries out feces thus reducing odor, mold, mildew and bacteria. The only real change for these species is the possible - yet not required body of water. Most of these monitors will spend a lot of time ina heated and filtered pool of water if provided. In order to accomplish this you will need a separate tank or appropriate size that can be heated and filtered to allow for clean water that is of the appropiate temperature. This is exclusive of a separate caging area that is dry. No monitor is so aquatic in nature that you can set it up with just a pool of water and small place to climb out onto. They will require large dry areas, yet a pool could be utilized - yet again, not necessary. Pools are hiding places, thus taming a monitor with a pool is very difficult, so I normally don't provide one untill the monitor is very tame. I normally use a 75 or 125 gallon fish tank with an appropriate sized filter and a large heater to heat the water to about 90 degrees. Then I build a cage up around the lip of the tank. In this fasion, the tank is simply a pool - not the cage, and the cage is up around the tank - and larger than the surface area of the tank. This will normally reduce cage cleaning dramiatcially as the monitor normally will defecate in the water only. Netting od excess fecal material is almost always required. Gravel is normally used in the bottom of the tank to collect detrital. Occassion gravel siphoning and water replacement will help keep the water quality high. Aboreal species such as the crocodile, black & green tree monitors obviously will enjoy large spacious cages with robust climbing features. I have found that for the crocodile monitor specifically, long 'running' cages are best. Rather than having a very tall cage that allows vertical movement, a long and tall cage is best. These cages are normally bedeed with cypress mulch and the humidity is kept rather high with daily spraying of the cages. The issue of mold, mildew and other water associated problems is still prevalent, yet airation tends to offset it. Hiding places are a key ingredient to the correctly setup monitor cage. Slabs of plywood with 1" or more separators screwed or nailed together - in multiple layers make the best hiding places for these types of monitors. So, if you can envision a piece of plywood with two 1"-2" spacers nailed into it, then another piece of plywood staked above the spacers, then again and again. This multiple layer hiding place will be frequented by your monitor very often. Most of these dry area monitors tend to wedge themselves into small places in layers of wood or rock - and will hide from the sun and potential predators in these hide outs. Aboreal species tend to prefer elevated hide boxes - similar to brid boxes - with a small opening to allow entry and exit. Heavy plant cover will also suffice if you can provide it - particularly for the green and black tree monitors. Most monitors - if not provided with the platform hide places will utilize any appropriate hide box added to that cage. Be certain to make these hide boxes secure and VERY sturdy. A water bowl is mandatory. Fresh water should always be available for your monitors. Water bowls can be problematic however as most monitors will defecate in the water - then turn around and drink from the bowl. The potential for bacterial infections are high here. The bowl should be just large enough to drink out of yet small enough to prevent the lizard from climbing into it. I always discourage placing a large water container in a monitors cage. There is the issue of defecation of course, and that water dissipates heat very quikly - thus making the water container the coldest place in the cage - coupled with a bacteria issue - it could be a cesspool of infectious bacteria. If your monitor sits in the cold water - it's immune system can be reduced due to a lack of body heat - and thus make it more susceptible to infection. Avoid this scenario. Water bowls can and will be frequently tipped over. You may want to seek a weighted water bowl. If you as the keep so desires, many a dry type monitor will enjoy a temporary soak in a pool of warm water. Provide this as a weekly husbandry practice. Get a plastic container with a lid. Put warm water to the touch in the basin, and allow your monitor to soak in it for about an hour or so once a week. The container's lid should have holes drilled into it to allow some air flow, otherwise it should be covered to increase humidity while the monitor soaks in the water. Cage size is always an important issue. It would be follish to state a 'preferred' cage size for any particular specie as many have hoe ranges in the wild of many acres which they sometimes frequent on a daily basis to seek prey, shelter and potentially a mate. A bssic guidline for captivity is that the cage should be 2-3 times longer than the monitor and of appropraite depth - to allow easy cleaning and turning space. Most of these dry area monitors are not necessarily climbers per se, yet that does not mean that if provided - they would not utilize climbing features. The height of the cage could be dependant on the devices required to heat it. The taller the cage, the more difficult it is to displace heat from the top to the bottom for proper basking. A common aquarium used for many monitors in captivity is the 55 gallon fish tank. I find this tank to generally be inappropiate for two reasons, it is generally to tall - and always to narrow. I always build cages that are no more than my arm length deep (because that is as far as I can reach to scrape crap off of the back of the cage). This depth allows very reasonable turn around space and of course more floor space. The length of the cage is dependant on the length of the lizard - 2 -3 times longer than the length of the monitor. Secure - water proof cages are required. Monitors will pry, pull, scratch and dig at every nook and cranny left available to them. Secure these features or your monitor will either get stuck or escape from them. I build cages that limit air flow as most humans prefer cooler temps in thier homes - so limited air flow reduces drafts and breezes and makes the cage easier to heat. It is a falacy that any reptile will grow to the size of its environment. Always expect to be able to house an adult of whatever monitor you have - so consider the eventual caging requirements as you will need them sooner or later. Bigger is always better - always, unless heating is an issue. Heating is perhaps one of the most important issues regarding the keeping of any reptile. Without proper heat a monitor can not digest food correctly, criculate blood, respire and its immune system will not work correctly if the whole system is not warm enough. Being ectotherms monitors require heat from thier environment. You must provide this. There are a number of ways to provide heat in captivity, some do cage heating - others with many reptiles do room heating. Most monitors are housed in single cages of appropriate size. In heating most cages I tend to encourage the use of ceramic heat emitters. These infrared heat emmitters are very good heaters because they het from the top down and heat surfaces and the air around them. They do not emit any light - this is very important as they can be used all the time. Monitors require a constant gradient of heat - 24 hours a day. They are not near artic species like garter snakes and thus do not endure dramatic changes in temp in the overnight. A basking site during the day could be provided with an incandescent light bulb, yet the extra heat may not be needed. If the cage is very big a ceramic heater can be used to heat one end and alight during the day only can be used as a basking site - and thus the photoperiod required to mimic day time. There should generally be a basking site that may reach 115F with average cage temps of about 85F depending on the specie - this is an average temp. I do not allow any drop in temps in the overnight for any equatorial specie of lizard. The hiding places will allow the monitor to thermoregulate on its own.mThose people that allow their monitors to free roam in a home must always be aware of thermal gradients. Hot air rises, cold air does not. When a monitor is not in its cage and allowed to walk on the floor - remember that the floor is the coldest spot in the room. When a door opens, cold air rushes across the floor. A monitor can be compromised by these cold drafts and breezes. Lighting for a long time has been the area of most confustion and controversy that is was difficult to know just what to do and how to provide for a monitor correctly. My opinon, based on years of experience and research indicates that monitors lizards require a photoperiod to tell them when to sleep and when to be active. This photoperiod can be provided with ANY form of light. It could be a regualr incandescent house light, a cheap florescent light - sun that comes through a window - anything. Anything that fits your budget. It has been my opinion and backed up by some studies that monitors DO NOT NEED any ulltraviolet radiation. Monitors have very heavily kerotinized scales that protect the monitor from harmful ultraviolet light, thus preventing skin cancer and dermal trauma that can be come from direct exposure to ultraviolet light over a prolonged period. Many people have been using the 'vitalights' for a long time under the pretense that monitors need ultraviolet light. This is false. There is NO proof that ANY varanid utilizes ultraviolet light in any way. In fact there is information that indicates that prolonged exposure in captivity to ultraviolet light causes cataracts and blindness. 'Vitalights' commonly produce so little ultraviolet light that thier use with reptiles that do need it (unlike monitors that don't) is negligeable. The common trade term of 'full-spectrum' lighting is perhaps hte most misused and least understood term in the trade. 'Full-spectrum' light simply means visible light. All light that is visible, this is broken down into the color spectrum of red, orange, yellow, green, blue, Indigo & violet combined they create a white light. Ultraviolet light is invisible. That means that anyone thinking they are getting ultraviolet light from a 'full-spectrum' bulb is being duped! Take my word for it - no special lighting needs for ANY varanid. The vitamin D3 issue is a non-issue with varanids. They get all the vitamin D3 they need from the livers and kidneys of thier prey.
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