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

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. Although by day it may appear quite docile it should not be approached too closely as some individuals may be unpredictable in temperament.

Nine subspecies are recognised by Reptile Database.

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 an example from Pulau Sugi with much reduced barring, and an example from Pulau Bintan with typical barring. This subspecies ranges from southern Myanmar and 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 (lowermost photo).

Other subspecies are recognised from Java/Bali (B. d. dendrophila), including a white-barred form of the latter from Bali, western Sumatra (B. d. occidentalis), Philippines (B. d. divergens, B. d. latifasciata, B. d. levitoni, B. d. multicincta) and Sulawesi (B. d. gemmicincta). Adults of the latter subspecies lack any yellow colouration and are wholly black.

A recent study (Weinell et al, 2020) concluded that B. d. melanota should be treated as a distinct species (i.e. Boiga melanota), separate from Boiga dendrophila.

Fig 1 : Example of B. d. melanota from Gunung Arong, Johor, Peninsular Malaysia.

Fig 2 : Example of B. d. melanota from Pulau Sugi, Riau Archipelago, Indonesia showing much-reduced barring.

Fig 3 : Example from Pulau Bintan, Riau Archipelago, Indonesia showing barring typical of B. d. melanota.

Fig 4 : B. d. melanota from freshwater swamp forest habitat in Singapore.

Figs 5 and 6 : Example from Kinabatangan River, Sabah, Borneo showing extensive barring typical of B. d. annectens.


References : H1, H2, H3, H4

Weinell, J. L., Barley, A. J., Siler, C. D., Orlov, N. L., Ananjeva, N. B., Oaks, J. R., ... & Brown, R. M. (2020). Phylogenetic relationships and biogeographic range evolution in cat-eyed snakes, Boiga (Serpentes: Colubridae). Zoological Journal of the Linnean Society.