Choosing the right Monitor Species for you.

[Oxylepy]

Too often are these animals impulse buys for people who see them as very young animals and decide to make a purchase for an animal they are not ready to care for. So, I'm here to help you make a good decision, instead of needing to rehome an oversized animal you cannot care for. This is based on my own desire to get a monitor species and really kicking around the idea of a Nile monitor, then realizing I needed to do a lot more homework before making the decision.

First and foremost: You have about 2 years after getting a hatchling to get your adult enclosure together. In most cases an adult enclosure is highly recommended before you decide to purchase the animal. But, let's be realistic, you likely won't do this and will make a lot of mistakes. Those mistakes may kill your pet. Or you may get lucky. But long term you're probably going to want them in an adult enclosure within the first 2 years of their lives.

The Enclosure
Determine available floor space. You'll want to be able to handle between 25-200lbs per square foot. That depends entirely on the species environment. Arboreal species require the least weight, burrowing land based species require the most. That may come up if you don't have a solid foundation to keep them on (basement floor, a shed outdoors, etc).
So, how big of an enclosure can you handle? Do you only have 2'x4' of space available as floor space for them? Can you handle 4'x8'? What about 5'x10'? A large shed? A barn?
As a good rule of thumb, the depth of your enclosure should be the length of your adult monitor, and the length should be twice the length of your adult monitor. So if you can't handle 6'x12', don't get a 6' monitor species. If you can only swing 2'x4', you're going to be limited to a 2' monitor. This is, in my opinion, the easiest way to thin the list of monitors you can get.

Secondly The Environment
Monitor lizards come in 3 primary environment requirements, many are a mix of the 3, and no I don't mean their biome, I merely mean where they spend their time. Land, trees, or water. If you want a species that spends a lot of time on the ground, or burrowed under it, you're going to be dealing with a lot of weight (savannah monitors for instance). If you want a monitor that spends a lot of time in the water, you're probably going to want a filtered swimming area for it. If you want a monitor that spends a lot of time in the trees, you're going to want a lot of height for your enclosure. Many monitors utilize 2 of these or all three heavily. Keep in mind that water and dirt are extremely heavy. Even deep wood shavings are heavy. Potentially too heavy to house anywhere but a floor which is directly supported by the ground. Honestly, some monitors will essentially require multiple cars worth of weight within one car's space.

Appearance
If you have choices by this point, you're doing really well. Actually this is where I began, which was a mistake, and the ultimate decision came down to my fiancee saying the lizard looked cute, while other similar appearance and requirement monitors did not.

Finally
Monitors tend to not be forgiving. Personally I am of the opinion that all reptiles are really easy to care for (even one of the most difficult lizards, the Emerald Tree Monitor). This is because I look at reptiles as: Get the environment right the first time, or you've killed the reptile. Sure a lot of reptiles are forgiving of this, and honestly that is one of the main things that separates the expert and the easy difficulties. But if you get it all right from the beginning, you'll probably be fine.

Don't expect the "play" with your monitor lizard. Don't expect to "tame" your monitor lizard. You can strive toward these ends, but putting all your heart into it is a very easy way to get your hopes dashed. Monitors are highly intelligent reptiles, often spirited, and they often cannot be "broken" only worked within their own comfort levels.

In the future I will end up giving a list of monitors, their sizes and which environments they are likely to need.

[jclaiborne]

I agree with most of what you said, however a few points, there isn't a single monitor species that will thrive in a 2ftx4ft enclosure. Even Ackies require a bigger cage than that, monitors and tegus are active. It is recommended that a 4ftx8ft cage is the bare minimum for all ground dwelling species. I can't speak to arboreal species since I haven't had any experience with them. Second, 2 years is too long to wait for the adult enclosure. These animals grow incredibly fast if given the proper husbandry from the beginning.

[Oxylepy]

I have to disagree completely in regards to enclosure size for ackies. Look up a number of the care sheets on them. 2'x4' is an acceptable minimum size for the enclosure's floor space. I've even found some that reduce this to about 2'x3' as a minimum. As always with monitors, larger enclosures are better. However, combing through a number of care sheets on a number of species, an enclosure of the animal's total length by twice the animal's total length is an appropriate minimum floor space, with some more arboreal species requiring less space on the floor and more space vertically.

And correction on the enclosure size, while it can take 2-3 years for a monitor to achieve full size, it will achieve as much as 95% of its full size within the first year. As such the adult enclosure is necessary within the first year, not within the second year. Although an enclosure of the full length of the monitor by 2 times the full length of the monitor is still suggested.

[jclaiborne]

Monitor keeping and large lizard keeping is really in its infancy, as far as proper husbandry is concerned. It wasn't long ago that people were just throwing them in cages with some cypress mulch and calling it good. Sure the lizards lived, for a little while, but they weren't thriving. I don't rely on care sheets that can be found online, because there is a lot of misinformation circling. I rely on the info from people that have successfully cared for and captive bred these animals for years, and after talking with a handful of people that have raised ackies I still disagree with the 2x4 enclosure. In an enclosure that size there is no way to get the proper thermal gradient required. My Tegu is in a 8x4x4 and I feel like that is too small for her, and the tegu is no where near as active as any monitor species.