Housing – The Basics
While the size difference between a hatchling enclosure vs an adult enclosure will obviously be quite different, there are a few things common to these setups which can be covered here.
Substrate
Our goal, having purchased an animal that seeks out burrows to regulate some of its bodily processes, is to provide a fair amount of soil. Many keepers have settled on the “two feet” rule, providing a depth of soil equal to the average burrow depth of the monitor in the wild, mentioned on the front page of this Housing section as observed by Daniel Bennett.
The necessity of burrows cannot be understated. Not only does deep soil allow the cold-blooded monitor the opportunity to seek out different environmental properties within the enclosure and move from warmer to cooler and drier to more moist or vice versa, a good burrow also allows a smaller monitor a back up plan if its feelings of security are violated.
While providing two feet of substrate is always admirable, any deep amount of soil will only benefit your monitor. Various keepers have used one foot of soil in raise up enclosures and the monitor successfully created a network of burrows.
The substrate must generally be a mixture of soil and play sand, in a soil to sand ratio of anywhere from 50/50 to 75/25. This should be eyeballed while mixing to determine what will best hold a burrow in your setup.
For the type of soil, use plain old dirt. Any home improvement store generally stocks their no-frills, store brand line of inorganic top soil. 40 pound bags go for as low as $1.50 in some states. The main thing to check is that it’s free of fertilizer/plant food/manure/etc. Even the most inorganic of soils will smell like soil for a short while, so if your house stinks of soil initially, give the enclosure a bit of time to settle in.
There are two pitfalls here that keepers fall into.
One is overcomplication. The idea is simply to use dirt and playsand. It doesn’t need to become a geology study. Anything without white plant food balls and cow poop will generally suffice.
Two is substitution. A soil/sand mixture means just that. It does not mean cypress mulch, Eco Earth(tm), coconut husk, walnut shells, or anything similar. While some of these contribute successfully to raising and holding humidity, none hold a burrow and do not allow the monitor the ability to seek out its own optimal environment.
Enclosure Size
The general rule of thumb for lizards of many species is that the absolute minimum requirements for an enclosure is that it must have a footprint where the length is 2x the animal’s length, and the width is 1x the animal’s length. This means that for a 2 foot bearded dragon, the minimum footprint should be 4 x 2 feet. For a 4 foot monitor, the minimum footprint will be 8 x 4 feet.
For our Savannah Monitor enclosures, you will need enough height to accomodate your deep substrate as well as the lights that must be inside the enclosure.
Lighting and Basking
The traditional single bulb spotlight focused basking area used as a standard by the pet industry is often not broad enough to cover the entirety of a larger monitor’s body. A focused beam as such can also generate spot burns. The goal is to use a row of lower wattage flood light bulbs and bring the basking area closer to the monitor, or use substrate or “furniture” to raise the monitor to the basking area.
Pre-wired pet store dome lights, because of the dome, prevent the lights from being close enough together to provide a consistent light stream. It’s preferred that a wired row of lights just in their fixtures be constructed. All electrical wire residing inside the enclosure should be enclosed in weatherproof casing or conduit, to reduce arcing and risk of fire from the humidity present. If you are not “handy”, please consult an electrician. We found that it’s easier to pay 1/2 to 1 hour electrician’s labor to get the sockets fitted and wired properly than it is to have a shoddily made fire hazard inside our house.
While it may seem dangerous to have free, uncovered bulbs inside an enclosure, for monitors the opposite is true. If they come in contact with the bulb, they will simply glance off the side without burn. On the contrary, it’s much more dangerous to have any kind of reflector, dome hood, or cage around the bulb as monitors can hang on items you never would have thought they could get to. Hanging on an added fixture item like a dome hood or bulb cage will definitely cause burning to occur.
For a visual picture, here is an example of a bank of flood lights, in an enclosure used with another species of monitor 1:
One of the pitfalls of monitor keeping is the belief that monitors require the same basking temperatures as other reptiles, including bearded dragons. While other reptiles may shy away from any basking surface temperature higher than 110F, monitors gravitate toward and make full use of surface temps in excess of 130F-140F without harm.
It should be noted that we are referring to surface temps as measured with an infrared temp gun, not ambient air temps.
Basking surface temps of 130F-140F can be achieved even with a bank of 45 watt flood lights close to the basking area.
Ventilation and Humidity
As we’ve discussed, the Savannah Monitor requires high humidity and is most active during the regional humid and rainy season. Ventilation is unfortunately the enemy of humidity. Any enclosure built for a monitor is going to need to be fully enclosed, with little to no ventilation.
A monitor will not suffocate in its enclosure, though it’s also assumed that you are actually opening the enclosure to feed the animal.