About Monitor Lizards
There are three species of monitor lizards in Singapore. The most common is the Malayan water monitor (Varanus salvator) that can grow up to 3m long. The other two species, the clouded monitor lizard (Varanus nebulosus), and the rarest Dumeril’s monitor (Varanus dumerilii) can grow to a length of 1m to 1.5m. Monitor lizards are mostly carnivorous; some also scavenge on dead animal matter. They can be found in forests, mangrove swamps, and even concretised canals!
Monitor lizards feed on a huge variety of food types (e.g. insects, crabs, snakes, fish). They control the population of their prey, and in turn are a source of food to larger predators such as crocodiles. Monitor lizards also play an important role as scavengers in biomass decomposition and recycling.
Why am I seeing monitor lizards in my neighbourhood?
Suitable habitats within urban areas and availability of food are reasons why you might encounter monitor lizards within your neighbourhood. Water monitor lizards are often found near our waterways as they use our canals to travel and hunt for prey. They are often mistaken as a crocodile when swimming in water. Clouded monitors are mainly terrestrial while they dig among leaf litter searching for invertebrates but can also be seen up on trees exploring tree cavities.
Do's and Don'ts
What should I do if I see a monitor lizard in an urban area?
Keep calm. Monitor lizards are generally shy and will not attack unless provoked.
Observe from a safe distance.
Do not attempt to handle the animal. If there is a need to rescue or relocate the animal, call NParks’ 24-hr Animal Response Centre (1800-476-1600) or ACRES (9783-7782).
In the unlikely case that you get bitten, seek medical attention immediately. While their venom is not lethal to humans, their bite can cause infections.
How can I keep monitor lizards out of my home?
Practise proper food waste disposal.
Seal up holes and gaps in your property which monitor lizards might enter from or hole up in (e.g. under pool decks or other cool crevices).
Prune trees and overhanging branches to restrict access into your property. Some monitor lizards are excellent climbers.
If you have an outdoor pond with fish, install wire mesh or acrylic panes at least 1m high around it.
Keep drains covered and cover up entry and exit points with wire mesh to minimise access to monitor lizards.
Keep your pets safely indoors.
To learn more about monitor lizards and other herptiles, you can join the Herpetological Society of Singapore for their guided walks and read more about them on their webpage.