Bornean Keeled Green Pit Viper
Tropidolaemus subannulatus
A venomous, strikingly patterned pit viper of Southeast Asian rainforests, closely related to the well-known Wagler's pit viper.
- Venomous?
- Venomous
- Adult length
- 0.5-1.0 m (1.6-3.3 ft)
- Range
- Borneo, Sulawesi, Philippines, and parts of the Malay Archipelago
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Overview
The Bornean Keeled Green Pit Viper is a venomous species found across parts of Borneo, the Philippines, and neighboring islands. It was long considered part of the Tropidolaemus wagleri complex before being recognized as a distinct species.
It is notable for pronounced sexual dimorphism, with males and females differing markedly in size, coloration, and pattern.
How to identify it
- Green base color with variable banding, often more pronounced in males
- Females significantly larger and bulkier than males, sometimes with duller coloration
- Strongly keeled scales giving a rough texture
- Triangular head with heat-sensing pits
- Vertically elliptical pupils
- Distinguished from other green pit vipers by keel prominence and regional distribution
Habitat & range
Found in lowland and hill rainforests across Borneo, Sulawesi, and the Philippines. Often encountered in dense vegetation, forest edges, and sometimes near human settlements bordering forested areas.
Behavior, diet & reproduction
Primarily nocturnal, coiling motionless on branches during the day and becoming active hunters at night. Preys on small mammals, birds, frogs, and lizards, using heat-sensing pits to locate warm-blooded prey. Reproduction is viviparous, with live birth of young after gestation.
Frequently asked questions
Is the Bornean Keeled Green Pit Viper venomous?
Yes, it is a venomous species and should not be approached or handled.
How do males and females differ?
Females are typically larger and bulkier, while males tend to be smaller and slimmer with more contrasting patterns.
Where does it live?
It inhabits rainforests in Borneo, Sulawesi, the Philippines, and nearby islands.
Is it related to Wagler's pit viper?
Yes, it was previously classified within the Tropidolaemus wagleri species complex before being split out.
Bornean Keeled Green Pit Viper guides
In-depth guides for identifying and understanding Bornean Keeled Green Pit Viper.
