Savannah / Bosc Monitor

Size usually ranges from 3.5-4.5ft though males can reach up to 5ft (exceptional though)

DISTRIBUTION: Bosc's monitors are the most commonly available monitor lizard in the pet trade. All those in shops are imported wild caught or captive farmed specimens, from Togo or Ghana. Hatchling Bosc's are about 15cm in length, adults reach around 100cm. Records Kept in the USA show these animals can live in excess of 15 years.

HOUSING: When housing Bosc's it is important to remember that they grow rapidly from their hatchling stage. The larger the vivarium you can provide the better. For an adult a minimum size would be 6x3x3ft . The structure should be sturdy, and front opening, with glass that is shatter proof (4mm+). Bosc's have extremely strong tails that they whip when agitated. Substrate for the cage can be any of a variety of materials, such as wood shavings,chippings or bark even gravel or newspaper. It should be easily replaceable, as Bosc's are messy when they defecate.

Bosc's like most large lizards need to feel secure, so a shelter must be provided. This can be as simple as a cardboard box, or more decorative like cork bark tube or a ceramic drain pipe.
These animals come from hot and arid countries.The day time temperature is high 85-90F(29-32C), night time temperatures can be allowed to drop by 10 - 15F(6-8C). All cages have a hot or cold spot it is a good idea to find out where these are using a min max thermometer. There are several heat sources to chose from such as heat mats, tube heater and heat lamps. it is best to find the one that heats your viv the most economically for its size. I have great success with heatmats.
Bosc's DO require UV light, without it they will not thrive. Artificial light should be provided to establish definite photo periods that may aid breeding.

DIET: Water should always be available in low sturdy dishes to avoid spillage's, the ideal would be a dog bowl. They do drink regularly even though the are from arid regions. They do like to have a soak, this however leads to defecation, do not allow this to stand around and disinfect before reuse. Bosc's are not usually fussy about what they eat, which can lead to problems of obesity when adult. Hatchlings will eat crickets, mealworms, baby mice. It is advisable to add a mineral and vitamin supplement such as Nutrobal or Reptivite. The size of prey should increase as the animal grows, hatchlings and animals up to 30cm should be fed every 2-3 days on rodents or chick with the occasional addition of crickets and cat food. Some like boiled eggs as a treat but it can be messy. Sub adults and adults should be fed 1 -4 adult mice per week. If the animal appears to be getting to fat then adjust the amount. Live crickets and locusts given on an occasional basis provides some exercise NO CAT FOOD TO BE GIVEN

HANDLING: Once you have bought your monitor, leave it alone in it's cage for a few days to get used to the change. Avoid moving suddenly around the animal. All Bosc's will bite if provoked or threatened. The threat display consists of a thrashing tail and a puffed out throat and a loud hiss. It may flatten the body either ventrally or laterally towards the aggressor. If the bosc does bite it has the ability to lock its jaws closed.
When handling a Bosc do so firmly and without hesitation. A thick pair of gloves may help to start with. Grab the Bosc behind the head to avoid bites and support the body with your other hand. If large enough tuck the tail under your arm to prevent thrashing. With regular handling most Bosc's will calm down. If your bosc bites, have a bottle of vinegar at hand to drip some into his mouth to make him release. Boscs have lockjaw and can and will hold onto you for hours if they feel threatened. If your bosc does happen to bite, allow him to calm down the next couple of days with minimal handling.


BREEDING: Breeding of these monitors is very rare in captivity. Due partly to the difficulty in sexing them. Methods which can be employed can cause serious damage and should not be undertaken by a novice. It should occur under veterinary guidance. Zoo's have had some success though not often repeated by following these guidelines;
1) Obtain a sexually mature and correctly sexed pair of Bosc's, that have a good covering of flesh but are not obese.
2) A rest period should be initiated by separating the pair and dropping the temperature by 10F for five to six weeks, decreasing the daylight to at least 14 hours darkness and reducing or stop feeding.
3) After 4-6 weeks reverse the above process.
4) Put the pair back together and once copulation has stopped this may take several weeks, separate the pair and provide the female with a tub of damp sand to mimic the termite mounds used for egg laying in the wild. The female lays between 8-50 eggs. they should be incubated in 50/50 w/w vermiculite/water at 29-30C they take 120-180 days to hatch.

REFERENCES: R SPRACKLAND Giant Lizards
Philippe de Vosjoli(1990) General care and
maintenance of Savannah Monitors
Herpetocultural Library series.
PRAS care sheet number 17
PRAS offers you this care sheet for your own information, should you wish to republish then please do not edit or reformat this sheet in any way and quote PRAS as the source.