Types of vipers

Tropidolaemus is a small genus of venomous snakes in the family Viperidae, within the pit viper subfamily Crotalinae. Like all pit vipers, its members carry a heat-sensing pit between each eye and nostril that detects the body warmth of prey. The genus is best known through Wagler's pit viper, the species that gives the group its common name because large numbers of them rest among the offerings at the Penang Snake Temple in Malaysia. Our database holds four species: Wagler's Pit Viper, the Bornean Keeled Pit Viper, the Broad-banded Temple Pitviper, and the South Philippine Temple Pitviper.

These are snakes of Southeast Asian rainforest. The genus ranges across southern Thailand, peninsular Malaysia, Indonesia, Borneo, and the Philippines, with individual species often tied to particular islands or regions. They are strongly arboreal, spending most of their lives coiled on branches, vines, and foliage in lowland and hill forest, frequently near water. Because they sit motionless for long stretches waiting to ambush prey, they can be easy to overlook in dense green vegetation.

In general terms, Tropidolaemus are stout-bodied snakes with a broad, triangular head clearly wider than the neck, vertical cat-like pupils, and a prehensile tail suited to climbing. Many show vivid coloring, green grounds banded or speckled with yellow, white, or black, and the sexes can look strikingly different, with females often larger and more boldly patterned than the smaller, brighter males. The combination of the heat-sensing facial pit, keeled scales, and an arboreal ambush posture is typical of the group.

These are venomous snakes and should be treated as dangerous. As pit vipers they deliver venom through long, hinged fangs, and a bite can cause significant local pain, swelling, and tissue effects. They are not aggressive and generally rely on camouflage and stillness rather than fleeing, which means bites usually happen when a snake is touched, grabbed, or stepped near. Never handle a wild Tropidolaemus and never assume one is harmless because it is sitting still. If a bite occurs, treat it as a medical emergency: keep the person calm and still, and seek professional care immediately by contacting local emergency services or, in the United States, Poison Control at 1-800-222-1222.

Ecologically, Tropidolaemus are sit-and-wait ambush predators. They feed mainly on small vertebrates such as lizards, frogs, birds, and small mammals, striking from a coiled position and using venom to subdue prey. Like most pit vipers, they give birth to live young rather than laying eggs. Their slow, deliberate behavior and reliance on concealment make them a classic example of how arboreal vipers earn a living by waiting rather than hunting on the move.