I thought it might be fun this week to take a look at the upgrade to the iguana terrarium the boys and I did this summer.
The outdoor iguana terrarium is 10 years old this year. The floor dimensions are 8 feet by 8 feet. I built the terrarium with solid walls that extend a couple of feet into the earth to prevent the iguanas from digging out. A little less than a foot above the ground, the top of the solid walls ended and chicken wire continued to the top of the terrarium a little over 6′ above the ground.
When we first moved here and built this terrarium the pair of iguanas that I owned were pets that I had raised for many years and were exceptionally tame and friendly. They were very happy and comfortable with the relatively open exposed feeling the chicken wire gave them.
Eventually they passed away and a couple of years ago I decided I would like some iguanas again and acquired a pair of adult invasive feral iguanas who previously were living on the streets of Miami.
Last year I noticed that although these iguanas seem very comfortable in their indoor terrarium, they appeared insecure in the outdoor terrarium.
Although they do not allow me to handle them like my old pets would, while indoors they have slowly become tame enough that they allow me to touch and pet them and hand feed them. If I am slow and gentle they even allow me to pick them up and move them. They spend most of the day up on their perches basking, and take an interest in their surroundings.
Last summer outdoors these same iguanas acted very wary, tended to hug the ground, almost never climbed up to bask, and I wasn’t happy with the amount of food they were eating (very little).
At first I thought they were just acclimatizing to their new surroundings and eventually they would come around and behave normally. They never did. Indoors again this past winter they immediately returned to being relaxed and feeding and behaving normally.
So when they started this summer acting wary and not eating well again outdoors, I decided we needed to add some security for them in their summer terrarium. I felt that by providing solid walls about half way up the terrarium, they could avoid being seen from a distance if they wanted, and they could thermoregulate and feed and otherwise behave normally in privacy, yet they could climb above the solid walls if they were feeling comfortable enough to get a look around and bask. At the same time, the solid walls below the basking sites allowed them a quick escape to privacy if they felt the need, and I believed that would make them more comfortable and give them the courage to climb up and have a look around more often.
Also, after 10 years, some of the untreated lumber on the door needed replacing and some of the panels of chicken wire had aged and needed replacing. I purchased the original chicken wire very cheaply on clearance because it was defective and already aging 10 years ago.
It looked like a good project to do with my teenage sons, and we tackled it in a couple of afternoons.
I am very happy with the results and very proud of the work the boys did, as they required only minimal guidance and help from me.
The iguanas love it. The solid walls worked even better than I expected. The iguanas quickly began behaving and feeding normally, and now spend a lot of time up off the ground basking with a full view of the surroundings without fear. Their weight is excellent, they are alert and responsive and although they still do not allow me touch them outdoors, they will hand-feed and allow me to approach closely without looking fearful. They look very happy and healthy.
If you own an iguana and don’t have an outdoor terrarium for your lizard, I highly recommend it. The sunlight and fresh air is wonderful for the iguanas, not to mention environmentally friendly and best of all heating is free! Care of an iguana in a large outdoor terrarium is greatly simplified with no lamps and little or no cleanup all summer depending on the rainfall (here it rains often enough that iguana poop regularly dissolves and breaks down quickly into the earth). It makes a nice break from the indoor winter care these lizards require. Also many people cannot have a huge indoor enclosure, so a nice large outdoor enclosure makes for a great vacation for the iguana.
If you are thinking about building an outdoor iguana enclosure like this for your lizard, there are some things I’d do a bit differently if I built the terrarium from scratch today. Firstly, I’d use single sheet solid walls 2 or 3 feet above the ground extending 18 to 24 inches below ground and not what we have done here. I would use galvanized steel roofing sheets. These are available new as “seconds” very cheaply. “Seconds” are just leftover pieces after a contractor completes a job and there is nothing wrong with the sheets. They are very strong, long-lasting, and look great. Secondly, I’d simply attach the wire above the walls, and I’d use the green rubber coated hardware cloth used for making rabbit cages and such, which is more attractive, has smaller openings, is stronger, and less abrasive than chicken-wire. Even very small iguanas could be kept in with the hardware cloth. Finally, I’d make the top about 7 feet off the ground so it is a little easier to walk around in.
I bring my iguanas outside in the spring when night temperatures remain above 50 degrees and they stay outdoors all summer until early fall when night temperatures again drop below 50. I don’t worry about day temperatures. Iguanas and other lizards are much like bricks. Solar radiation warms their core and they build heat in their bodies until they are a good bit warmer than the surrounding air even when day temperatures are relatively cool. Some cool lazy days especially at the end of the summer where they tend to brumate a little are fairly natural and seems to help “cycle” my iguanas for breeding which usually occurs immediately when they return indoors in the fall.