One of Asia’s most striking and photogenic venomous snakes—an emerald-green beauty with a deadly secret. This elegant arboreal viper is named after the Norwegian-American zoologist Leonhard Stejneger, who made major contributions to the study of reptiles in Asia.

Its most striking feature is its brilliant green body, often contrasted by a white or yellowish line running along the sides, and in males, a vivid reddish or pink stripe below that line. The head is broad, triangular, and distinct from the neck, giving it the classic pit viper look, while the eyes are large with vertical pupils, perfect for nocturnal hunting. The tail tip is sometimes reddish or brownish, which may serve as a lure to attract prey. Beneath this beauty lies a potent arsenal—the snake’s hemotoxic venom is used to immobilize prey quickly, but it is rarely life-threatening to humans with proper medical treatment.

The Stejneger’s pit viper is an arboreal ambush predator, spending most of its life in trees, shrubs, and bamboo thickets. It prefers humid, forested areas at both low and moderate elevations and is particularly active at night. During the day, it can often be seen resting motionless on a branch, coiled neatly and blending perfectly with the leaves. At night, it comes alive—waiting patiently for frogs, lizards, rodents, or small birds to wander within striking distance. Its heat-sensing pits, located between the eyes and nostrils, allow it to detect the body warmth of prey even in total darkness, giving it an edge as a silent night hunter.

Though venomous, the Stejneger’s pit viper is not aggressive and will usually rely on its camouflage to avoid danger. If threatened, it may coil and hiss as a warning but prefers to remain still, trusting its green disguise to keep it hidden.

Distribution

Country

Population est.

Status

Year

Comments

Cambodia

2011

China

2011

India

2011

Sikkim, Assam, Darjiling

Laos

2011

Myanmar

2011

Taiwan

2011

Vietnam

2011