The monitor lizards

They surely belong to the lizards that have inspired the most myths among the general public and are synonymous with monstrous giants!

However, if you take the time to take an interest in them, you realise that they are fascinating, magnificent animals about which we in fact still know little.

They can be found in various biotopes (desert, tropical forest, seashore, rocky areas). Its most famous representative is the Komodo dragon, which can reach 54 kg and is the only lizard capable of making a human its lunch.

Monitor lizards are generally diurnal and carnivorous. They are also reputed to be the most intelligent lizards.

Housing

• In captivity, monitor lizards are divided into 2 groups:
• Those that reach a size greater than 120 cm
• Keeping them requires bespoke installations, or even purpose-fitted rooms.
• Those whose size is under 120 cm.
• They can be kept in a terrarium.
• No glass terrarium for timid species that would bump into it as they flee. Front opening with sliding doors and locks! Good ventilation. Bathing area.
• Heating with a ceramic lamp. Thermostat + guard. Creation of localised hot spots. Roughly between 22 and 40°C or so (each species is more or less different). In the wild, they spend hours basking in the sun, to warm up but also to benefit from the UV rays essential to their good health. Lighting must therefore be provided.
• For arboreal species, branches and foliage, cork against the terrarium walls. For terrestrial species, a hollow trunk, stacked flat stones, planks, etc.
• Substrate: depending on the species' biotope (if tropical, shavings or pine; if dry, beech shavings or calcium sand possibly).
• Hygiene is very important for the animals' health: disinfect the terrarium once a week, change the water dish every day, and always handle the animal with clean hands. Also avoid overly obsessive cleaning to prevent excessive stress.

Diet

• In the wild, a diet of birds, mammals, insects, eggs, amphibians, crustaceans, arthropods.
• In captivity, get as close as possible to this variety. Insects, dusted with calcium and, for the monitor lizard's physical exercise, lizards, other mammals and birds. First and foremost they need food rich in calcium.
• Juveniles will be fed every day in good quantity, likewise breeding females post-operatively. Males will be fed more moderately. Beware of obesity!
• Pay great attention when feeding, using long tongs. And one prey item per monitor lizard, with the greediest kept apart.

Reproduction

• Few observations to date. Oviparous, with a variable number and size of eggs. Still a great deal of missing knowledge at present, and difficulty in sexing.

Protection

• Monitor lizards have always been victims of humans, whether because of their beliefs, for their meat, or for their skin.
• All monitor lizard species are currently protected, which applies to specimens whether alive or dead (in the form of skin) (Washington Convention).
• Creating reserves and developing serious captive breeding programmes are surely the only solutions for certain species to escape total extinction.

Common diseases

In monitor lizards, most health problems are linked to diet and to the terrarium setup.

The main thing to remember: a healthy monitor lizard depends on a well-designed terrarium (heat, UV, secured hot spot) and a balanced diet rich in calcium.

A lack of calcium weakens the skeleton and debilitates the animal. Conversely, food that is too rich or too plentiful quickly leads to being overweight (obesity), which is common in inactive males.

Parasites (internal or external) are common, especially in a recently acquired animal. They can lead to weight loss or abnormal droppings despite a good appetite.

Finally, a poorly protected hot spot (lamp, ceramic) can cause burns. The monitor lizard, which seeks out heat, injures itself against a heat source that has no protective mesh. Branches and corners can also cause wounds.