monitor lizard

Monitor Lizard Facts

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Lizards in the monitor lizard family are some of the largest lizards in the world.

These reptiles are primarily native to Asia, Africa, and Australia, but can also be found in parts of the Americas thanks to the illegal pet trade. Monitor lizards are known for their large claws, powerful tails, long necks, and well-developed legs. They can chase prey quickly and vigorously. Most monitor lizards are terrestrial and primarily carnivorous. Depending on the size of the lizards, they will eat anything from insects and birds to small mammals.

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5 Incredible Monitor Lizard Facts!

  • Monitor lizards are considered the smartest of all lizards and one of the smartest reptiles.
  • Monitors don't blink and they have excellent eyesight. Scientists observed monitors watching the aircraft in the sky.
  • Unlike many other reptiles, many monitor lizards have high metabolisms and burn energy like mammals.
  • As a pet, monitors have been observed to seek human attention and want to play.
  • Monitors are alert and skilled predators. Although they are dangerous to small animals, their bites are not fatal to humans

monitor lizard scientific name


Monitor lizards belong to the kingdom Animalia, phylum Chordate, class Reptiles, order Squamata, family Varanidae, and genus Varania . There are many subgenera of monitor lizards, including:

  • embagusia
  • Urbiron
  • Odateria
  • Bapron
  • Philippine dragon
  • Myriads
  • salon
  • Solomonosaurus
  • South Dragon
  • monitor lizard

The scientific name Varanus comes from Arabic and means dragon or lizard beast. The standard English name for monitor lizard probably comes from the reptile's habit of standing on its hind legs and looking around.


The genus Varanus consists of a wide range of species. The earless monitor lizard is a rare species of monitor lizard that lives in Borneo. It is the only species in the monitoring subfamily Lanthanotinae . It looks a lot like other monitors with slender bodies, but with smaller-than-normal limbs.

Examples of other species include:

Health and Recreation at Monitor Lizard

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  • Ackies dwarf monitors (Varanus acanthurus): These monitor lizards live in Western Australia and are known for their pale red color with creamy dots. They are mostly insectivores, although they may nibble on cat or dog food when kept in captivity. They can grow up to 27 inches long.
  • Argus monitors ( Varanus panoptes ): Capable of growing up to 5 feet, they are land animals that love to dig holes. Despite being kept as pets, they still scratch with their sharp claws when trying to break free. They are native to Australia and New Guinea.
  • Asian water monitor (Varanus salvator): Second only to the Komodo dragon in size, these monitor lizards are semi-aquatic animals with strong swimming abilities. They live in mangroves, swamps or wetlands and can grow up to 6.5 feet.
  • Emerald Tree Monitor Lizard (Varanus prasinus): These tree-dwelling monitor lizards are especially popular with pet owners because of their bright colors. However, they don't mind leaning on their teeth when they get scared. Reptiles can grow to about 40 inches.
  • Crocodile monitor lizard (Varanus salvadorii): Dark green and yellow-spotted, these giant crocodiles are fairly stealthy and are notable for their exceptionally long tails. They live in the tropical rainforests and mangrove swamps of New Guinea and West Papua.
  • Gray's monitor lizard ( Varanus olivaceus ): Terracotta-coloured, with a broad dark band around the body and profusely scattered yellow spots, these monitor lizards can grow up to 6 feet long. Arboreal and reclusive, they prefer to eat the fruit of the pandan tree, although they are also partial to crabs, birds and spiders.
  • Nile Monitor Lizard ( Varanus niloticus ): Capable of growing to 7 feet, they are the largest monitor lizard in Africa. They live along the Nile and are able climbers and swift runners. Florida is also home to a group of escaped and abandoned wild monitor lizards that were once pets.
  • Peacock monitor lizard ( Varanus auffenbergi ): Shy and reclusive, these small monitor lizards are lighter in color and thinner, with dark bands dotted with turquoise spots. They can grow to 60 cm and are excellent climbers.
  • Black-throated monitor lizard (Varanus albigularis ionidesi)
  • Black Tree Monitor Lizard ( Varanus beccarii )
  • Dumeril's monitor lizard ( Varanus dumerilii )
  • Earless Monitor Lizard ( Lanthanotus borneensis )
  • Lace display (Varanus varius)
  • Mangrove Monitor Lizard ( Varanus indicus )
  • Peach-throated Monitor Lizard ( Varanus jobiensis )
  • Rock Monitor Lizard ( Varanus albigularis )
  • Rough-necked Monitor Lizard ( Varanus rudicollis )
  • Savannah Monitor Lizard (Varanus exanthematicus)
  • Timor monitor lizard ( Varanus timorensis )


Experts believe that the ancestors of monitor lizards originated in Asia, based on their discovery of archaosaurs that lived there during the Eocene Epoch, 56 to 33 million years ago.

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It's worth noting, however, that Saniwa was also a species of monitor lizard and another close relative that lived in Wyoming at the same time 48 million years ago. It shared the same features that monitors share today, such as a tail nearly twice its body length and a thin, tapered snout.

However, the story of the genus goes back 66 million years, or even earlier, during the Late Cretaceous period, when the evolutionary branch of Varanus split off from the earless Varanus, which happens to be their closest relative.


Young desert monitor lizard (Varanus griseus). Uzbekistan Tank Zilkum Desert.

©Sergey Dyonin/

Types of monitor lizards vary greatly in appearance and size. The smallest species of monitor lizard grows to only eight inches long. However, several species are very large, reaching lengths of 7 to 10 feet. Regardless of size, monitor lizards have relatively thick bodies with long necks, well-developed legs, and long tails. Colors vary widely, most commonly in mottled shades of brown, black, gray, green, yellow, and blue.

Komodo Dragon vs. Monitor Lizard

Are Komodo Dragons Venomous or Dangerous?
Komodo dragons are the largest monitor lizards and can grow up to 10 feet

© Andrey Gudkov/

The Komodo dragon is actually a monitor lizard. Its scientific name is Varanus komodoensis . The largest of the monitor lizards, the Komodo dragon can grow up to 10 feet long and weigh up to 300 pounds. Komodo dragons are also recognized as the most dangerous type of monitor lizard, and a few attacks on humans have been recorded.

Komodo dragons look broadly similar to other monitor lizards, but they tend to be larger and heavier. Most other types of monitors have a slimmer profile. Komodo dragons also have unusual skin compared to other monitor lizards. Its skin has tiny bones called lamellae, which add to its toughness against predators.

Therefore, the dragon's skin is very rough.


Monitor lizards are usually solitary reptiles, but in some areas with limited water resources, monitor lizards gather in groups of up to 25 individuals. Otherwise, monitor lizards usually live a solitary life until they come together to breed. Monitors are mostly terrestrial and are most comfortable moving on land – especially for larger species. There are also a number of arboreal and aquatic monitoring species.

Most monitors are completely carnivorous. Monitors generally avoid humans, but can be dangerous if provoked. They are faster than they appear and have strong jaws and tails. Monitors can be very aggressive in protecting their territory or food. Many monitors are active hunters, stalking and chasing prey. Other types of monitors are more interested in cleanup.


Some monitor lizards are aquatic, some are arboreal, and most are terrestrial

© Gunaratna

These lizards are easily found in Africa and Asia and on the islands of Oceania. They can now be found in parts of the Americas, but due to their non-native status, they are considered an invasive species. Monitor lizards in the Americas originated in the exotic pet trade. Monitor lizards are adapted to a variety of environments. They can be found in jungles and rainforests, as well as in bodies of water and in hot, dry areas.

Water monitors like the Asian water monitor live in coastal areas with semi-aquatic habitats such as swamps and mangroves. They are also adapted to places with canal systems, such as those found in Sri Lanka.

Arboreal monitor lizards like the Timor monitor lizard spend most of their time in trees. They have long tails and sharp claws that are great for climbing branches and trees.


The diet of these lizards depends on where the reptile lives as well as its size and type. Tree monitors tend to eat insects and birds. Some species of tree monitors eat mainly fruit. Water monitors tend to eat anything they can find in the water. This includes fish, waterfowl, insects, eggs and aquatic mammals or reptiles. These primarily terrestrial lizards, such as Komodo dragons, may eat a variety of live prey and carrion. A Komodo dragon's diet consists of about 50 percent deer native to its islands. Komodo dragons have been known to eat pigs and cows if they can get them. These lizards are opportunistic predators.

For a comprehensive analysis of what monitor lizards eat, we published "What do monitor lizards eat?" 11 foods in their diets.

What do monitor lizards eat?

Large adult monitors have few predators. Smaller monitor lizards and small lizards may be eaten by birds, other reptiles and lizards, feral cats, and humans.

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What do monitor lizards eat?

Food is varied and includes fruits, insects, birds, fish, mammals and reptiles.

Predators and Threats

Bald eagle in flight
Birds of prey have been known to feed on monitor lizards


For the largest species of these lizards, the primary predator is humans. In the leather trade, humans hunt certain types of monitor lizards for their hides. The only exception is the Komodo dragon, whose skin is rough and rough and not suitable for leather. As with all types of monitor lizards, juvenile lizards are predated by other lizards, snakes, large birds, fish, and big cats. These animals also prey on smaller lizards as juveniles and adults.

The conservation status of these lizards depends on the species. For example, Komodo dragons are considered vulnerable. On the other hand, the conservation status of water monitoring in Asia has received the least attention. Panay monitor lizards are considered endangered. The decline in these lizards is largely due to habitat threats, dwindling water resources and human hunting.


newly hatched monitor lizard on hand
Monitor lizards popular among exotic pet lovers


There are five different species of monitor lizards that can be kept as pets and they are:

  • Ackie Monitor
  • Black Throat Monitor
  • diphtheria monitor
  • water monitor
  • Savannah Monitor

The Ackie is one of the best monitor lizards to keep as a pet. By monitoring standards, Ackies are a relatively small species, which alone has an advantage. Ackies are usually about 2 – 3 feet long as adults and are yellow and red in color.

There is no individual difference between the two color variations.

Although these pets are exotic and rare, they have grown in popularity over time.

Reproduction, Babies and Longevity

Closeup of Emerald Tree Monitor
Most young monitor lizards will climb onto tree branches to increase their chances of survival


Males usually fight to mate with females. Komodo dragons usually mate between May and August and then lay their eggs around September. Female lizards are often hostile to males, which means the males must fully restrain them when mating, or they may get injured.

These lizards usually lay their eggs in hidden nests underground. They may also place them in hollow stumps. The exact method varies by species. For example, Komodo dragons may lay their eggs in abandoned ground nests, or they may lay their eggs in holes in the ground or in hills. Some monitor species can lay as many as 30 eggs. Komodo dragons lay about 20 eggs. Nile monitor lizards have an ingenious method of laying eggs by digging them into termite mounds. Termites naturally cover the hole, thus providing a safe and warm place for the eggs. When the eggs hatch, the small lizards usually eat the termites before leaving the mound.

Because young lizards and unhatched eggs are attractive to many predators, not many young lizards survive the initial brood. Young land monitors probably spent most of their early life in trees to avoid predators.

Most of these lizards live at least 20 years. Komodo dragons can take up to nine years to fully mature. They can live up to 30 years old. Larger monitors tend to live longer than smaller species.


There are about 80 species of this lizard in the world. The smallest species live in trees or in water, and population data are unknown for most of them. The rare earless monitor lizard is an example of a species for which population data are unknown. Due to its small range, it is considered vulnerable. However, earless monitors are nocturnal and not often seen by locals. Many of the smallest monitors have unknown data. Large species like Komodo dragons are protected in some areas from declining numbers. Loss of food sources and habitat are the main reasons for the decline in monitored populations. Monitored populations tend to increase in these areas if food and habitat are abundant.

in captivity

There are many zoos across the country where you can see Komodo dragons and other monitor lizards, including:

  • Bronx Zoo
  • louisville zoo
  • Fort Worth Zoo
  • Toledo Zoo and Aquarium
  • Smithsonian's National Zoo
  • Pittsburgh Zoo

similar animal

  • Iguana: Large and brightly colored, they are considered an invasive species in some areas and are beloved by pet lovers in others. Learn about this reptile that can grow up to 7 feet.
  • Komodo Dragon: With a maximum length of over 10 feet, it is simply gigantic. This is not only dangerous but also clever. Discover everything you need to know about this powerful ambush predator.
  • Skink Lizard: Some are aquatic and some are arboreal. They are found all over the world. Here's everything you need to know about these reptiles that lay eggs and have young at the same time.
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Monitor Lizard FAQs (Frequently Asked Questions)

Are monitor lizards herbivores, carnivores, or omnivores?

Most monitor lizards are primarily carnivorous. However, many people are omnivores, eating fruits and vegetables in addition to meat.

To which kingdom do monitor lizards belong?

Monitor lizards belong to the animal kingdom.

What class do monitor lizards belong to?

Monitor lizards belong to the class of reptiles.

What phylum do monitor lizards belong to?

Monitor lizards belong to the phylum Chordate.

What family do monitor lizards belong to?

Monitor lizards belong to the lizard family.

What order do monitor lizards belong to?

Monitor lizards belong to the order Squamata.

What type of mulch do monitor lizards have?

Monitor lizards are covered with scales.

What genus do monitor lizards belong to?

Monitor lizards belong to the genus Varanus.

What type of habitat do monitor lizards live in?

Monitor lizards live in riparian and coastal forests.

What are monitor lizards' main prey?

Monitor lizards prey on rodents, snakes, and lizards.

Who are the monitor lizard's natural enemies?

Natural enemies of monitor lizards include humans, snakes, and feral cats.

How many babies does a monitor lizard have?

The average number of babies in Monitor Lizard is 10.

Any interesting facts about Monitor Lizards?

Certain species of monitor lizards are thought to have weak venom!

What is the lifespan of monitor lizards?

Monitor lizards can live from 8 to 30 years.

How fast are monitor lizards?

Monitor lizards can travel at speeds of up to 28 miles per hour.

What do monitor lizards eat?

Monitor lizards eat a variety of foods, including insects, crabs, other reptiles, fish, deer, rodents, carrion, fruit, and more.

What is a Monitor Lizard?

Monitor lizards are a lizard family that includes some of the largest lizard species in the world. They vary in size but are characterized by long necks and tails, chiseled limbs, and elongated bodies.

Where do monitor lizards live?

Most monitor lizards live in Africa, Asia and Australia.

Can monitor lizards kill?

Large monitor lizards are technically capable of killing humans. Most monitors are shy and will avoid humans, but may attack if provoked. Monitor lizards have powerful jaws and bodies and can run fast enough to catch humans. There have been documented instances of Komodo dragons killing humans, but these are still rare. One of the greatest dangers to monitor lizards is their bite. All monitor lizards are thought to secrete some amount of venom, and the bites of these lizards can also become infected.

Are Komodo dragons and monitor lizards the same thing?

The Komodo dragon is a type of monitor lizard, but the monitor lizard family is diverse and includes about 80 different species.

Are monitor lizards good pets?

Monitor lizards are considered difficult pets for beginners. However, they are also known to be very intelligent, and some are very docile and even friendly. Some can also be very aggressive and unpredictable. In general, it's easier to care for smaller monitors as pets than larger monitors, which can require a lot of space.

Why is it called a monitor lizard?

Monitor lizards are thought to get their name from the environment in which certain species are accustomed to standing on their hind legs and looking around.

How Do Monitor Lizards Have Babies?

Monitor lizards lay eggs.

Who will win the battle between the king cobra and the monitor lizard?

The king cobra would win the battle with the monitor lizard.

In most cases, the average monitor lizard is too small or slow to react to defeat a king cobra. Once the cobra bites the monitor lizard, the timer starts to die. Of course, large monitor lizards may fight back. It might even grab the king cobra's head and bite down, but its chances of getting the first and only coup de grace in this fight are slim.

What's the Difference Between Monitor Lizards and Monster Lizards?

The biggest differences between monitor lizards and Gila monsters include their size, location, and appearance.

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  1. Wikipedia, available here:
  2. National Parks, available here:
  3. Encyclopedia Britannica, available here:
  4. Daily Science Journal, available here:
  5. Biology Dictionary, available here:
  6. Switch Zoo, available here:
  7. National Geographic, available here:
  8. Pet Helpful, available here: