Taxonomists have disagreed about how to classify both the species and subspecies of this brown and striped giant from Tanzania in southern Africa. This lizard commonly known as the black-throated monitor lizard is a large reptile with a surprisingly mild temperament when kept as a pet. As with its cousins, the white-throated monitor and the savannah monitor, their temperaments in the wild might be ornery, but they are often relatively gentle in captivity when they receive proper care. This lizard should only be kept by an advanced reptile keeper as these monitors require an extremely large enclosure; they can grow to be over 60 pounds!
Common Names: Black throat monitors, black-throated monitors, Ionides monitors, cape monitors
Scientific Names: Varanus albigularis ionidesi, Varanus albigularis albigularis, Varanus albigularis microstictus
Adult Size: Up to 7 feet long and more than 60 pounds
Life Expectancy: 20 years or more
Black-Throated Monitor Behavior and Temperament
Black-throated monitors are semi-arboreal, meaning that in the wild they live mostly up in the trees, especially as juveniles. Adults don't climb as much as the juveniles, but they are still able to lumber up a branch whenever they need to escape dangers on the ground or to forage in a tree for food.
These diurnal (day dwelling) lizards also like to spend a good amount of time burrowing or hiding under rocks, but black-throated monitors are also playful creatures that need stimulation; otherwise, they get bored and restless and may lash out as a result.
Most small lizards, such as geckos and chameleons, generally prefer not to be handled by humans. But the larger lizards of the monitor family actually need interaction in order to habituate them to their owners. Some studies suggest that these lizards are intelligent enough to recognize their human keepers.
If not handled regularly by humans, black-throated monitors in captivity may become aggressive. When they feel threatened or stressed, these large animals will puff up their bodies and hiss; they have even been known to bite. Given the animal's size, a bite from one can do some serious damage. If you see your monitor lizard starting to puff up, back away and leave the animal alone until it shows signs of calming down.
Stress is very bad for reptiles, as it can lead to a weakened immune system and a host of subsequent health problems. As with all pets, exercise is a good stress reliever. In warm weather, black-throated monitors can be walked outside just like dogs (albeit a bit slower) using a harness and leash. This is great for your monitor in many ways; socialization, UVB rays, and exercise are all good for its overall health.
Housing the Black-Throated Monitor
A black-throated monitor lizard requires a large and strong enclosure. Most owners end up building a permanent enclosure for their black throats out of wood or plexiglass. The enclosure must be large enough for your monitor to walk forward a few steps, turn around, and generally stretch out.
Provide your heavy reptile with a variety of places to both climb on and bask. Shelves at various heights and sturdy branches for climbing provide your pet with areas to explore and places to bask up near ceiling heat lamps. Add additional ramps and secondary ways to climb up and down.
A hard plastic kiddie pool or utility tub with ramps added for easy access and exit will be appreciated by your lizard even though monitors are not strong swimmers. Get a tub with a drain for easy cleaning since the water usually needs to be changed daily. You will also need a protected heater for the water to keep the temperature around 80 F.
Even big monitors need a place where they can feel safe and secure so a hiding area should be provided. Use plywood to build an inverted wooden box to serve as a hiding area. Make sure that all furnishings in the cage are bolted securely in place.
Monitors lizards are also diggers, so they need to have an earthen floor (the substrate). Add a deep layer of substrate material to the enclosure; clean dirt mixed with sand is sufficient. Vinyl or tile flooring can be used under the substrate as well, since it is easily cleaned. But digging claws may damage this layer of material.
Since these lizards hail from Africa, they like hot temperatures. Tanzania has a tropical climate where it stays over 68 F year-round (except at the higher elevations). Provide your monitor lizard with a basking area that reaches into the upper 90-degree range during the day while staying above 75 F at night.
Monitor lizards need a source of UVB lighting for roughly 12 hours per day to remain healthy. Sunlight is the best source of UVB, but it is not always available. Sunlight through windows is also not a source of UVB as the glass filters out these invisible rays.
Like other monitor lizards, black throats require the addition of UVB ray support. Reptile heat lamps and special UVB emitting bulbs can be used to provide your pet with appropriate temperatures and a day/night cycle that includes the rays that the sun emits. If you've decided to house your black-throated monitor outside year-round and it gets natural sunlight, then artificial UVB lighting is not necessary.
Food and Water
In the wilds of Tanzania, black-throated monitors are obligate carnivores, which are true carnivores that cannot digest plant matter. They eat small reptiles, birds and eggs, rodents, aquatic animals, and insects. In captivity as well, they need to eat many whole prey items such as mice and birds. Rats, and other rodents along with young chickens are generally good options for meals. Crustaceans, fish, eggs, snakes, lizards, and even freshwater shellfish are also all fair game and offer good variations to the diet.
Insects, such as crickets, mealworms, and cockroaches can be fed to monitors in addition to their regular meals of rodents and birds. If you do feed insects, dust them with a calcium powder first, and make sure the insect has been gut-loaded.
While their wild-caught counterparts may only want to eat live prey, captive-bred monitors are willing to eat previously-killed prey. Most monitor owners buy previously-killed, frozen mice in bulk online and thaw them as needed. There is some debate as to whether these lizards need to stalk or hunt before eating, but if they've been raised in captivity it's likely that this primal instinct has been suppressed.
Feed your monitor a few times a week and adjust the meal schedule if your pet becomes too thin or overweight. Weigh your monitor monthly so that you can adjust feedings as needed.
Use sturdy bowls for food and drinking water. Using bowls that can be firmly attached to the side of the cage is the best way to prevent spillage. Even if your monitor has a pool for wading, a freshened water bowl should still be provided.
Common Health and Behavior Problems
If your black-throated lizard seems lethargic or otherwise unwell, don't try to treat these symptoms yourself. Seek treatment from an exotic animal veterinarian who specializes in lizards.
Like other monitor lizards and many other pet reptiles, black-throated lizards are susceptible to metabolic bone disease, which is the result of a calcium-phosphorous imbalance that usually occurs when the lizard isn't getting enough UVB lighting to make Vitamin D.
A significant health concern to watch out for with any large lizard is constipation due to impaction. Like other big lizards, black-throated monitors have voracious appetites, and often that means they eat things they cannot easily digest, like the sand or substrate from their cages.
Although they are known to get parasitic infections, black-throated lizards don't get them as often as the smaller lizard species. The presence of parasites often indicates inadequate husbandry conditions that can be rectified with adjustments in housing, but safe medical treatment by a veterinarian might be required.
Choosing Your Black-Throated Monitor
These are large, strong reptiles that can be challenging pets for this reason. Be sure you have the resources available to house and feed such a big animal. It's also important to check the local laws regarding owning any exotic species where you live.
As with most exotic pets, it's best to obtain them from a reputable breeder who will tell you its health history. Clear eyes, smooth skin, and general alertness are all signs of a healthy black-throated monitor lizard. If it appears lethargic or doesn't take food readily when offered, it may be ill.
Similar Species to the Black-Throated Monitor
If you're interested in monitor lizards as pets, check out these similar species:
Otherwise, check out other types of reptiles and amphibians that can be your pet!