Water Monitor

20 Sep

Varanus salvator

Water Monitor Varanus salvator

Water Monitor in Lumpani

Water Monitor Varanus salvator

Water Monitor exiting water in Chatuchak

Water Monitor Varanus salvator

Extremely heavy monitor over 2.3 meters long in Phra Phadaeng

Water Monitor Varanus salvator

Water Monitor in water in Lumpani

Water Monitor Varanus salvator swimming

Water Monitor swimming in Lumpani

Water Monitor Varanus salvator

Water Monitor approximately 8 meters high in tree in Phra Khanong

Water Monitor Varanus salvator head shot

Head shot of Water Monitor in Lumpani

Water Monitor Varanus salvator eating fish

Same Water Monitor eating fish in Lumpani

Water Monitor Varanus salvator hunting

Water Monitor hunting snails in Lumpani

Water Monitor Varanus salvator

Water Monitor hunting along shoreline in Lumpani

Water Monitor Varanus salvator juvenile

Juvenile Water Monitor in Suan Luang

Water Monitor Varanus salvator juvenile

Juvenile Water Monitor in Phra Phadaeng

Water Monitor Varanus salvator mating

Water Monitors mating in Lumpani

English name: Water Monitor
Scientific name: Varanus salvator
Thai name: Hea

Description: To 3.21 meters long. Snout to base of tail is up to 1.1 meters. A massive, intimidating lizard, one of the largest in the world. The heaviest individuals can weigh over 50 kilograms. Body is grey to black, often with varying spots and chain patterns of yellow-to-tan that fade with age. Neck is long and head is long and somewhat flattened. Has a notably large forked tongue that it often extends to sense its environment. Tail is higher than it is wide and very strong. Underbelly is somewhat lighter than rest of body.

Similar Species: No other lizard in our area has the enormous size or distinct appearance of the Water Monitor.

Habitat: As their name implies, Water Monitors are almost always found near water, including rivers, lakes, swamps, canals, and beaches. As long as water is available they can be seen in a wide variety of habitats, including forests, grasslands, mangrove swamps, islands, and agricultural areas. They are most common in coastal regions and become increasingly rare the further inland you go. They are very good swimmers and are known to swim long distances in the ocean, which can lead to the colonization of new islands. They are also good climbers and are often seen resting in trees at heights up to 10 meters. The Water Monitor has adapted well to urban environments and can often be seen in Bangkok’s parks, canals, and garbage dumps.

Contribution to the ecosystem: Are an adaptable and prolific predator, helping to control insect, snail, shellfish, crab, fish, frog, snake, turtle, bird, and rodent populations. They are well-known for eating eggs, hunting for the nests of birds, turtles, and crocodiles. Monitors help keep the city clean by feeding on trash and dead meat, especially dead fish and other water animals that wash ashore. Young monitors can provide food for large snakes.

Danger to humans: Water Monitors do not prey upon humans, preferring to eat much smaller animals. However, a Water Monitor that is grabbed or threatened by a human may use its teeth, claws, or tail to defend itself, and all three could inflict significant injury. If you are bitten by a water monitor, it is important to clean the wound and apply antibiotic ointment immediately, as rotting flesh in the monitor’s mouth may lead to inflection. You should seek medical attention in the case of any serious bite in order to prevent infection. It is possible that very serious bites from the largest monitors may lead to fatalities.

Conservation status and threats: Is a widespread and common species in Thailand. Though they are sometimes killed for sport or out of fear, they adapt surprisingly well to urban environments for such a large lizard. They are a protected species in Thailand.

In other countries, Water Monitors face heavy hunting pressure for their meat and skins, and the combination of overhunting and habitat destruction has led to their extermination in some places. They are considered to be nearly extinct in China, and their populations have seen serious declines in India, Bangladesh, and parts of Indonesia.

Interesting facts: The Water Monitor is an inauspicious lizard in Thailand. Its Thai name is an insult referring to an evil thing. Superstitions state that it indicates bad luck, and some Thais will even avoid saying its name. The negative connotations associated with monitors may have to do with their eating of dead animals, their feeding upon household chickens and eggs, or their frightening appearance.

Wikipedia: Water Monitor
Ecology Asia: Malayan Water Monitor
Mampam Conservation: Water Monitor
Animal Diversity Web: Varanus salvator
Nam Kading Research & Training Center: Water Monitor
Hong Kong University: Varanus salvator
IUCN Red List: Varanus salvator
Thailand Office of Environmental Planning and Policy: A Checklist of Amphibians and Reptiles in Thailand
Michael Cota, personal communication.
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Reptiles of South-East Asia
The Lizards of Thailand


Posted by on September 20, 2011 in Lizards, Monitors


Tags: , , , ,

14 responses to “Water Monitor

  1. CK

    September 16, 2012 at 8:36 pm

    Very useful site, thank you! I saw one in Lumphini park and was wondering what it was!

  2. Sam202

    March 13, 2015 at 5:34 am

    Their was one on my front lawn is Singapour we where in the middle of a drought and it tride to get in our pool is this commen.

    • Asian Herp Blogs

      March 15, 2015 at 3:50 pm

      I don’t know many people with swimming pools, but that behavior doesn’t surprise me at all.

  3. me

    April 15, 2016 at 11:24 pm

    i just want to know about the teeth

  4. me

    April 15, 2016 at 11:25 pm

    i just want to know about the teeth why

  5. mel lee

    February 14, 2017 at 1:54 am

    I keep reps in the uk & cant wait to see water monitors in their natural environment


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