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Savannah Monitors

by Amy Magness

Unfortunately, we have all seen monitors built like bowling balls because of their tendency to be overfed. It is perhaps not just how much, but what type of food we feed our Savannahs that matters most. In order to properly care for them at home, we must look to how mother nature cares for them in the wild. It is this reason that I took notice of an article by David H. Good in the February, 1998 issue of REPTILE magazine. The article is entitled Misunderstanding the Savannah Monitor: An Argument for Changed Husbandry. According to Good's article, most of the information currently available on the Savannah, also called the Bosc Monitor (Varanus exanthematicus), is based on field data for White Throat Monitors (Varanus albigularis albigularis) of Southern Africa. Savannahs are the white throat's smaller cousins which inhabit areas further north. This regional difference is one reason that current information is inaccurate.

The climate of N. Africa has three basic seasons, hot/dry, cold/dry, and hot/wet. The effect this has on wild populations of Savannah monitors is that they will feast during the four months of hot/wet abundance, and then fast for the remaining eight months. It makes sense for the monitors to do this, since plant and insect life thrive during the four hot/wet mouths and annual drought leaves food in scarce supply. During this period of feasting, a Savannah uses its keen senses of sight and smell to locate delicious insects. Believe it or not, there is no evidence that they eat vertebrate prey at all. Wild Savannah Monitors primarily eat insects and smaller percentages of eggs and snails. The lizard will eat up to one-tenth of its own body weight in a day to store fat for the period of fast.

The hot and cold dry periods make for landscape which is rough and barren. It would not make sense for a cold-blooded animal to expend valuable energy searching for a scarce meal when it could remain inactive, alert but stationary. It is not hibernation (although temperatures can fall below 50 degrees Fahrenheit during the cool/dry period), but a period of fasting and reduction of caloric output. Now the Savannah relies on fat reserves it has in its tail and in adipose bodies of the abdomen. This way the lizard can make it through the worst weather periods.

David Good's article made me realize that many monitors are cared for as though they are living in an endless feasting period. No wonder they are as eager as "Mikey" was to eat anything that came their way. Now I don't think that we should put our monitors in the cold and not feed them for eight months, but perhaps it would be worth trying to meet them half way. The author proposes [that] a gradual cooling is beneficial to monitors over 18 months of age, especially if you hope to breed them. As for feeding, a change is definitely needed to keep these animals from becoming obese and to allow them to live longer, healthier lives.

A Savannah monitor should have a cage that allows for a thermal gradient. On one side of the cage it could be 80 degrees, while on the other a basking site would be provided with a hot spot of 105 degrees. After the animal is 18 months old, the temperature can be allowed to drop gradually over a three month period until it has cooled down to the 50's and 60's. After being dormant for 2-4 months, the temperature is gradually raised until it is warm again.

An invertebrate diet is what a Savannah Monitor should be fed. Of course a healthy animal could eat an occasional pinkie or mouse without creating a problem. It is just a continuous high protein, fatty diet (mice and eggs) which leads to obesity, liver disease, and other health problems which will shorten the life span of your monitor. A monitor can be kept healthy on a diet of crickets, waxworms, caterpillars, earthworms, lean ground turkey, snails, roaches, and similar low fat protein sources. This would be a delicious meal: according to The Lion King's "Pumba" and "Timone", "Slimy yet satisfying."

I hope everyone gets the chance to read this article in its entirety. I only rambled on about a few of the highlights. There are other interesting facts about Savannahs, their care, and the author's experiences breeding these lizards.