Varanus exanthematicus care sheet.

[morallywrong]

Bosc Monitor Care Sheet
Varanus exanthematicus

Bosc monitors are among the most commonly kept Varanids in society today. They are also one of the most misunderstood Varanids in captivity. Their life expectancy can be up to 30 years but is more typically between 10-15 years. They can grow up to 4.5 feet total length, however most are around 3.5-4 feet. They are prone to obesity in captivity, mainly due to an overabundance of easily accessible food and very little exercise. It is often commented, that Boscs should not be fed on small insects (such as crickets and locust to name a few), after they have started to grow, as these provide little nutritional value. While this is partially true In that they have to be fed in quite large numbers to be of nutritional benefit, they are however of great benefit in the exercise aspect of their husbandry in small quantity’s if you chose to feed an rodent based diet. Should you feed a defrosted rodent, then the Bosc will simply find the rodent eat it, then go and bask to digest its food. If however you give it 100 large crickets, it will run around for some time trying to catch its food. This is a normal part of its natural behaviour and an important part of its husbandry in captivity. It is therefore important to try to vary the diet, offer cockroach’s, cricket’s, locust’s snails etc. One of the main reasons that Boscs die prematurely in captivity, is incorrect husbandry. Primarily incorrect diet, often leading to a very friendly or lethargic Bosc, which will show little activity. This is often put down to a tame and friendly animal, that has been reared to act as such. However, this is all too often actually a very obese and simply unhealthy animal, that needs urgent attention before its life is cut very short by fatty liver disease or any amount of other illnesses that can onset an unwell monitor in captivity. I will try to explain my methods, which work well for me, in the next few sections. It is important to point out, these are my experiences and they work for me, however one of the most important parts of reptile husbandry is to learn to sift through the vast amounts of information available and to use what makes sense. Too often, simply because it is in a book (that may have been written many years ago), people stick to the methods in the book. They believe they must be correct. The husbandry of captive Varanids has come an awful long way in the last few years and as such is constantly being reassessed, to make sure we give the animals in our care the best possible life in captivity today.

Natural habitat:
Boscs come from a large portion of Africa, from sub Saharan and northeastern Africa and from Senegal in the west into Sudan and Egypt in the eastern regions. They are found in very dusty grassland but always near water. It is a common misconception, that they are found in very arid areas. Normally you will find them in burrows, basking upon rocks and foraging for food. They use the position of the sun in deciding when to forage, when to sleep and when to bask. They are normally found in savannah grassland near rocky outcrops, where they love to bask. They are scavengers or creatures of opportunity, they will eat most insects, scorpions or spiders, they will eat all kind of snakes and lizards and will often feed upon free meals that may be lying around. Given the choice, as it is in the wild, they tend to stick to inverts and snails, which offer a more healthy diet. They are truly amazing lizards, that are very good at surviving some very harsh and unaccommodating conditions. They have recently been described to me, By Daniel Bennett, in this way “In my experience this lizard feeds exclusively on invertebrates and snails, never on carrion. It is therefore the most specialised of the African monitors”. Another misconception is that they live in very arid areas. This is simply not the case given the choice they always live near a source of water however, from time to time they will of course have to "do without", when it is not available, at this time they will get moisture purely from their food.

What is a healthy Bosc
A healthy Bosc is a difficult thing to classify, however my definition would be an active inquisitive animal that while it has fat reserves on the base of its tail, can still stand up without its belly touching the floor. If your monitor occasionally scrambles as you try to pick it up, this is often a sign of a healthy animal over the one that sits there and would seemingly allow you to put it on its back without batting an eyelid. The main areas of health that are normally of concern are diet and lack of exercise. Often unsanitary conditions rears its ugly head. Ask yourself this when looking at your animal, does he look active and healthy? It's an important thing to ask and be honest with yourself. Very fat and lethargic monitors in the wild are simply the next meal for some predator. Active alert monitors, are the ones that have a greater chance of survival in captivity and in the wild.

Behaviour and general tips:
Do not forget Monitors are among the most intelligent reptiles there are, as such they will quickly learn a routine. If you therefore only open the door to its viv when offering food, they will associate this with "time to feed" and you don’t want the monitor associating the viv opening only with food, unless you want a nasty bite through no fault of the monitor. Never go near your monitor after handling anything that smells remotely like a source of food. Try to keep your monitor mentally active. In the wild they have vast landscapes to explore, try to make its new home as hospitable and accommodating to its needs as possible. They love to dig, they love to bask and they love to choose differing types of substrates to hide in. I have experimented with placing some hay across the floor of sections of the adults vivs, to try to replicate the savannah landscape more accurately. Some adults liked to sleep in this hay, some seemed to not use it at all. The point is try things, think it through and try to make your monitor as happy and content as possible. You will be rewarded with an extremely happy and healthy monitor and a far better viewing experience by doing so.

What Should I keep My Bosc in?
Well this is another area of debate. I would recommend that you keep your hatchling Bosc in a 2ft x2x2 vivarium. Use a background temperature of about 80-90°F and a basking site of 110-120°F, this can be achieved by using a 100-watt normal spot bulb, guarded of course, along with a good quality source of UV. I personally opt for the 7% UV 23 watt energy saving light bulb, available from arcadia. I have a mesh roof and half height mesh at each end with glass doors and a solid back. I also have a tray placed underneath my viv. I fill this with one half coconut fibre and one half calci sand or playsand (It should be noted that there is cheap calci sand available which is too hard and can damage your animals. The best way to tell is to place some in a cup of water, if it dissolves this is safe to use, if not then I would advise against using it). This allows the Boscs to burrow down into the substrate and make a nice home for themselves to feel secure in, they often sleep in this section but spend most of the day searching for food in the top section of the viv. They are often observed in the morning, sitting at the entrance to their burrow warming up, before going out and searching for food. Older animals need the viv size increased as time goes on. My adults, who are about 4feet total length, live in a 6x3x2 viv with a burrow section underneath. In this larger style viv, I mimic the smaller one, except that I use an Active UV bulb of 100 watt, which allows me to have a very localised basking site of up to 150°F, which quickly dissipates around the area to allow the same 85 -90°F background temperature. In older Boscs, it is important to allow them to choose the level of basking site they prefer. Mine will often sit in the warmest area of the basking site, then move slightly further away from it, which then is in the 120°F area of the basking site, where they will sit most of the day basking. This allows them to bask properly, which aids good digestion and keeps them fit and healthy. Make sure you give them a nice deep substrate, they love this and it is the best thing you can do for them. I would say one adult would be ok in a viv about 3ft deep, 1ft substrate 2ft of head room give it at least 3ft wide but 4 is better and around 6ft in length. The other thing you want to do, is get a good active UV or halogen setup in one corner, with a stack of either MDF on top of bricks so you have a shelf or two. They can then chose to sit on top of or underneath to bask. I don’t use MDF, I use concrete slabs because they soak up the heat better, however lots of other monitor keepers use MDF or plywood. Then you want to put amongst the substrate, some sheets of wood, to provide the burrows better support. A very good "Substrate Mix" to use is 30% top soil 50% peat and 20% coconut fibre bedding. Mix in as much water as needed to acquire the best consistency to aid construction of the burrow, remember the mix must be fairly firm because the larger the lizard the more likely the burrow will collapse if it's not firm. In addition, a nice large pool of water that is as big as the monitor is, if not bigger, so it can submerse in it. This will make keeping the viv cleaning easier too, as they nearly always defecate in the water. If not then they normally select one part of the viv to use as toilet, so again you don’t need to go hunting in the Viv for its waste. More than one basking spot is good but be careful not to use a non-light emitting heater, such as a ceramic, as lizards generally do not associate heat without light very well.

Handling:
Handling your Bosc can be a scary time, no matter if you are dealing with a 6 inch hatchling o a 4.5 ft adult, just remember no matter how scared you are, the animal will likely be more scared than you are. The best way to avoid being bitten by a Bosc, is to pick it up by placing one hand around the base of its neck from above. So that your fingers are either side of its neck and resting over its arms. This will not allow it to be able to either scratch you, or bite you. Place your other arm underneath, to support the body of the animal. Remember if it feels unsafe, it will likely scrabble around to try and obtain a suitable grip. With time, you and the Bosc will become more tolerant of each other however, you should never mistake tolerance for tameness, these are wild animals and as such can easily mistake you for food or a threat at anytime and inflict a very painful bite. I would therefore suggest from a young age getting your Bosc used to having its claws trimmed and you wearing gloves, so that it does not damage you too much should it mistakenly bite you. I would suggest thick welders gloves, as these come up high on your arms and will stop your arms from being scratched, as well as stopping the Bosc from being able to inflict too nasty a bite. It should be noted that if you are bitten, you should seek medical advice as soon as is possible, as the bacterial content is unlikely to be very nice and if you were bitten without gloves this could be a very deep and very painful wound.

Diet:
I feed my monitors either a rodent, or raw red meat every 3 days. I also offer them insects every day. I have also offered raw ground turkey, once every week to my adults, many zoos feed a diet of primarily ground turkey, however this leads to some very smelly clean up jobs and many keepers argue that they need the roughage of whole food items. I like to keep the diet varied and interesting, so do not use this diet. This allows them to get the required exercise they need, however I will vary the amount from time to time in response to my Monitors behaviour and what that tells me. If my monitor has become lazy and stopped searching for food, then I will wait for it to start searching again before feeding it, this enables it to keep a healthy balance of exercise and enables it to not become too comfortable in its "sitting around waiting for its dinner to come to it" lifestyle. In the wild, these varanids will walk for miles searching for food, often taking whatever opportunities come along. Which explains why, when in a small area in captivity, they often become obese. Boscs can very easily become the couch potato of varanids given the chance, it is up to us as keepers to make sure this does not happen, for the sake of the animals health? I find crickets and locust make up the exercise part of the diet quite well, put in one mouse and watch the monitor find it and eat it then sit there and not move. Then chuck in 100 crickets and watch the monitor run about trying to get them. Some refuse crickets when adult but most don’t and most will take locust which are just as effective if not slightly more expensive to use.

Breeding:
Breeding this species is quite uncommon and it is certainly not done for the money that can be made, more for the love of knowing your animals are content enough to do so. With so many Boscs brought in from the wild so cheaply, breeding these animals in captivity will most likely cost you more than you would make from selling the offspring, however a dedicated few have undertaken this challenge and have had a degree of success with doing so. The main things they seem to have in common (however you should note that too few have been bred in captivity to state these are the right things to do) are that a deep dirt substrate is offered, around 2ft seems to work best, good basking temps as discussed earlier. Often multiple basking sites work better than single site setups when trying to promote breeding success. There is also a degree of luck involved, as cycling seems to have little effect. The main things seem to be 2-3 suitably healthy and correctly sexed animals typically 1.2 - 1 male and 2 females works best. However, you may have to change the male or, momentarily, introduce another male to spur breeding behaviour. There seems to be little desire to stick to seasons in captivity with some and much success with others, so again this needs to be taken into consideration with your group. Most that have bred these animals in captivity, have been unable to repeat the feat, this suggesting a degree of luck in getting them to breed in the first place. However, some have been able to get the to breed on many occasions and with different animals. While these people seem to have no special husbandry, other than what we have discussed, they do "listen" to there monitors, which is, after all, the best way to get good results with any aspect of husbandry. Once they have been able to breed them, the eggs are incubated at 30°C, and hatch between 132 days - 169 days however, there have been higher and lower temps reported to have equal success. I would suggest staying at these recommended temps for better results all round.

Reading Your Monitors:
What do I mean by reading your monitors? Well simply, that observe what they tell you. Some will like temps at the higher end of the scale, some will like them at the lower end. Some will like more food than others, some will be more active than others. In the wild, your Monitor, if it does not like the environment it is in, will walk off to a more suitable environment. In captivity however, you have to customize your setup to your monitors needs, as this is the only way your monitor will get the desired results. I have often observed with many monitors when young, that they like to be arboreal however, they are not an arboreal species. It is thus up to us as the keepers, to provide it with an arboreal setup until we witness that it is no longer desired. If your Bosc appears to be panting no matter where it is in the viv, then maybe your temperatures are too high. Just because you have read they need a 150 basking site, this does not mean your particular Bosc will want it this hot, it is merely a guideline which you are to interpret with the help of your animal. You can place a Bosc in a small tank, with low temps, no suitable basking sites, no cage furniture and feed it mice or rats every day and it will be docile tame? And live for many years. However if you provide that same Bosc with a nice bathing pool, a nice deep dirt substrate and offer it a good basking site, nicely laid out cage, it will live a much more entertaining life for both you the keeper and it as the captive. After all why did you want the Bosc in the first place, to enjoy it, so give it the chance to have an interesting life and you will not be sorry.

[joeyboy]

aaah! Looks good but could you space out the paragraphs? Makes it easier to read...but that might just be me...

[morallywrong]

Originally Posted by joeyboy

aaah! Looks good but could you space out the paragraphs? Makes it easier to read...but that might just be me...

No Probs

Done and Done!!

[Razaiel]

This is good, very good! Especially agree with the mention on feeding and not making them couch lizards! Excellent article

[monitor mad]

Well written and good information , how long have you kept bosc's for?

do you still keep them , just curious as the info is good but reads like a book