The monitor lizards are large lizards in the genus Varanus.
There are 79 species of monitor lizard.
They are found in Africa, central and southern mainland Asia and Malaysian and Indonesian islands, Papua New Guinea, and Australia (where about half the species are found); and now found also in the Americas as an invasive species.
Monitor lizards come from many different corners of the planet, and as a result reside in many different types of habitats.
The average lifespan of most monitor lizard species varies from 8 to 30 years.
The adult length of extant species ranges from 20 centimeters (7.9 inches) in some species, to over 3 meters (10 feet) in the case of the Komodo dragon the largest living lizard on the planet.
Most species have an elongated head and neck, a relatively heavy body, a long tail, and well-developed legs. Their tongues are long, forked, and snakelike.
Although normally solitary, groups as large as 25 individual monitor lizards are common in ecosystems that have limited water resources.
Most monitor species are terrestrial, but arboreal and semiaquatic monitors are also known.
Monitor lizards have sharp and sensitive eyesight. They can see objects from far away and use this advantage to identify pray and keep their distance from predators. Their visual field spans 240 degrees.
Most monitor lizard species are carnivorous and often consume large insects and spiders, other lizards, small mammals, birds, eggs, amphibians and fish. The Komodo dragon is known to capture much larger prey such as water buffalo. Some species also eat fruit and vegetation.
Monitor lizards differ from most other known species of lizards in that they have a high metabolism. This means they must be fed more often than other lizards. In fact, while they are referred to as “lizards,” monitors are thought to be most closely related to snakes.
They are considered rather intelligent and have even shown the ability to count as high as 6.
Monitors primary method of communication is via their movements and their posture. They will make various noises – hissing when threatened and at times, a sneezing like sound.
Monitor lizards are oviparous, laying from 7 to 37 eggs, which they often cover with soil or protect in a hollow tree stump. Some monitor lizards, including the Komodo dragon, are capable of parthenogenesis (a natural form of asexual reproduction).
According to IUCN Red List of threatened species, most of the Monitor lizards species fall in the categories of least concern but the population is decreasing globally.
The generic name “Varanus“ is derived from the Arabic word waral/waran ورن/ورل, from a common Semitic root ouran, waran, or waral, meaning “dragon” or “lizard beast”.
In English, they are known as “monitors” or “monitor lizards”. The earlier term “monitory lizard” became rare by about 1920. The name may have been suggested by the occasional habit of varanids to stand on their two hind legs and to appear to “monitor”, or perhaps from their supposed habit of “warning persons of the approach of venomous animals”.
The family Varanidae probably originated in Asia at least 65 million years ago.
Partial fossils of Megalania prisca, an extinct Australian monitor that lived during the Pleistocene Epoch, suggest that it exceeded 7 meters (23 feet) in length and likely weighed nearly 600 kg (about 1,300 pounds).
Monitor lizards have become a staple in the reptile pet trade. The most commonly kept monitors are the savannah monitor and Ackies monitor, due to their relatively small size, low cost, and relatively calm dispositions with regular handling.
The skin of monitor lizards is used in making a carnatic music percussion instrument called a kanjira. It is an instrument of the tambourine family.