Focussing on the vertebrate
 fauna of SE Asia
  

 

Home  
——————————  
SE Asia fauna ...  
   
Primates
 Carnivorans
 Large Mammals
 Small Mammals
 Bats
—————
Birds
—————
 Snakes
 Lizards & Crocodilians
 Turtles
—————
 Amphibians
 Tadpoles
FFrogs & other calls
—————
Fishes
—————
Species Lists
 








 
——————————  
  SE Asia Vertebrate Records  (SEAVR) 2019  
——————————  
New Guinea fauna ...  
   
Snakes
 Lizards
 Frogs
 
——————————  
 Articles & Publications
 News Links
 
——————————  
 

Search this site ...

 
 


   

 
  ——————————  

Recently added ...
 
 
     
 
     
 
 
——————————  
     
   
     
    Links :  
  HOSCAP Borneo  
  Context Institute
  Herpetological Soc. Singapore
  HabitatID  
  Primatewatching  
  Orang Utan Appeal (UK)  
  Wallace Online  
    Citizen Action for Tigers  
    Nature Society (Singapore)  
  Traffic  
     
  Email :
 
     
  Text and photos by Nick Baker, unless otherwise credited.
Copyright © Ecology Asia 2019
   

 

   
   
 
Rough-necked Monitor
   
   

Fig 1


Fig 2
 

Fig 3
 

 

 

 

 

Family : VARANIDAE
Species : Varanus rudicollis
Size (snout to vent) :  up to 51 cm
Size (total length) : up to 1.32 metres ?

This species of monitor lizard appears to be rather uncommon, as sightings are quite rare. It occurs in a broad range of habitats including lowland swamps, stream gullies in hilly areas, and lower montane forest to around 1200 metres elevation. It has also been reported from mangrove habitat, which is also a typical haunt of the larger and more common Malayan Water Monitor.

The species is called Rough-necked Monitor due to the presence of enlarged nuchal scales (i.e. the scales on the back of the neck) which are strongly keeled. Other identifying features include the long, pointed, convex snout, the base of which is markedly concave.

The nostril lies midway between the tip of the snout and front of the eye (unlike the Malayan Water Monitor where the nostril is near the tip of the snout). The skull bears a strong ridge above the eye. The neck is relatively long, and the tail may be up to 1.6 times the snout-vent length.

The species is mainly dark grey throughout, with yellowish banding across the back and yellowish mottling on the neck and limbs. Juveniles are more strongly marked than adults. 

This lizard may be encountered on the forest floor, near streams, on fallen logs or on tree trunks. Typically it takes shelter inside tree holes. Little is known of its feeding ecology,  though crabs appear to be part of its diet in  habitats where there are sufficient crabs.

The Rough-necked Monitor occurs in southern Burma, southern Thailand, Peninsular Malaysia (including the southernmost state of Johor), Sumatra and Borneo. There are no records, historical or recent, from Singapore.


Fig 1 : Example from Panti Forest, Johor, Peninsular Malaysia, sunning itself on the trunk of a dead tree.

Figs 2 and 3 : Specimen recorded in a rocky gully in lowland, secondary forest, southern Peninsular Malaysia. The lizard was active by day, apparently searching for prey.


References : H11