wetlands
a publication of Sungei Buloh Wetland Reserve
Vol 13 No 3

Is that a crocodile or a monitor lizard?

Special projects to Understand Nature (SUN Club)

Dragonflies and Damselflies of Sungei Buloh

The Kranji Countryside: Singapore's very own countryside

Migration monitoring at Prince Edward Point BIrd Observatory, Ontario, Canada

Selai Endau Rompin Johor National Park

A feathered friend from Thailand		  
Is That a Crocodile
or a Monitor Lizard?


Ramakrishnan Kolandavelu
Assistant Conservation Officer


Many who have visited Sungei Buloh Wetland Reserve could have mistaken a monitor lizard for a crocodile.

One of the most commonly seen reptiles in the Wetland Reserve is the Malayan Water Monitor Lizard (Varanus salvator). This reptile is often mistaken for an estuarine crocodile (Crocodylus porosus), which is also found in the Wetland Reserve.


Compared to the monitor lizards, crocodiles are rarely sighted. That has changed recently as one particular crocodile has chosen to be a special attraction. Often seen with its eyes just peering out of the water surface, this crocodile has established its territory along Sungei Buloh Besar (the main river of the Wetland Reserve). It is often seen swimming under the Main Bridge, and on occasions crosses overland to the brackish water ponds to thermo-regulate (cooling down or warming up).

If you do come across a crocodile along the route or are not sure of the identity of the animal, remain calm and back away slowly. Do not try to walk pass it or get close for a photograph. Note that these animals are wild and have a reputation for being aggressive.

Crocodile warning signs have been posted at various parts of the Wetland Reserve where they are most often spotted. For your own safety, please heed these warning signs.

You can report crocodile sightings to our information counter staff. Take note of the location, date, time and number of crocodiles seen. The information will help us monitor and track the crocodiles’ movements.
Estuarine Crocodile
(Crocodylus porosus)
Malayan Monitor Lizard
(Varanus Salvator)
Distribution: Most widely distributed of crocodilians. It is found throughout the tropical regions of Asia and the Pacific.

Habitat: Brackish and freshwater areas.

Size: The largest crocodile can grow up to 8m. Some in captivity weigh up to 1000 kg.

Diet: Birds, fish, and mammals.

Physical Description: It has a very large triangular head, a pair of ridge that runs along the centre of the snout and a receding tongue. Its eyes are situated at the top of its head. The tail is made up of pointed plates, which is grey with dark bands. The younger crocodiles have scales that are oval in shape and pale yellow in color with black stripes and spots on the body and tail. The adults is much darker, with lighter tan or grey areas. 		Distribution: Asian subcontinent from India (and Sri Lanka Southeast Asia to Indonesia, the Philippines and in Indian Ocean and South China Sea.

Habitat: Both fresh and saltwater, common in mangrove, banks of large rivers. Also found in forests, swamps, beaches and even cultivated land.

Size: The males are 1-1.3m and females are 0.5-1.2m. It can weigh up to 25kg.

Diet: Tiny insects to crabs, molluscs, snakes, eggs (of birds and crocodiles), fish, eels, birds, rodents and even other monitor lizards.

Physical description: This large greyish lizard has an elongated head with a forked tongue, which it sticks in and out regularly to “smell” its prey. Its eyes are situated more to the side of its head. Juveniles are more brightly colored with bright yellow markings on the body and yellow bands on the tail. Its compressed tail can be twice as long as its body.

References Cox, M.J., Paul van Dijk. P., Nabhitabhata, J. and Thirakhupt, K., 1998. A Photographic Guide to Amphibians and other Reptiles of Peninsular Malaysia, Singapore and Thailand. New Holland.

Lim, K. K.P and Francis L K Lim, F. L. K, 1992. A Guide to The Amphibians and other Reptiles of Singapore. Singapore Science Centre.
   
© Sungei Buloh Wetland Reserve