Specimen from Pulau Sugi, Riau Archipelago, Indonesia showing much-reduced barring.


Specimen from Pulau Bintan, Riau Archipelago, Indonesia showing barring typical of B. d. melanota.


Specimen from Kinabatangan River, Sabah, Borneo showing extensive barring typical of B. d. annectens.
 

Family : COLUBRIDAE
Species : Boiga dendrophila
Maximum Size : 2.5 metres

References : H1, H2, H3, H4

Also known as the Yellow-ringed Cat Snake, or Mangrove Snake, this distinctively coloured species is unmistakable.

It occurs mainly in mangrove or riverine habitats. By day it lies motionless on overhanging branches, but at night becomes active coming to the ground  and feeding on other vertebrates including rodents, small birds and their eggs, frogs, bats and sometimes other snakes. It is also an adept swimmer.

This is a venomous, rear-fanged species. Though it may appear quite docile by day it should not be approached too closely as some specimens may be unpredictable in temperament.

Various subspecies are recognised. In B. d. melanota the yellow bands do not extend over the back but are confined to the flanks. Examples are shown here from the Riau Archipelago, Indonesia including a specimen from Pulau Sugi (top photo) with much reduced barring, and a specimen from Pulau Bintan (middle photo) with typical barring. This subspecies ranges from southern Thailand, through Peninsular Malaysia and Singapore, to eastern Sumatra and the Riau Islands.

B. d. annectens is confined to Borneo, and in this subspecies the yellow bands are more numerous and extend fully across the back (bottom photo).

Other subspecies are recognised in Java (B. d. dendrophila) and western Sumatra (B. d. occidentalis). The species also occurs in Sulawesi and the Philippines.     

In all subspecies the supralabial and infralabial scales (those above and below the mouth) are yellow with black edges.