How to Differentiate a Venomous Bamboo Pit Viper from a Non-venomous Greater Green

Hong Kong is home to a rich variety of snakes, including two strikingly similar bright green species: the venomous Bamboo Pit Viper (also known as the White-lipped Pit Viper) (Trimeresurus albolabris) and the harmless Greater Green Snake (Pytas major). Mistaking one for the other can lead to unnecessary fear or, conversely, dangerous situations.

As a hiker, especially if you enjoy night hikes, it really pays to know the difference between the Bamboo Pit Viper and Greater Green. While it is extremely unlikely that you will ever be bitten by a snake, the chances aren't zero. This guide will help you identify Hong Kong's two green (colored) snakes and understand what to do if you encounter one in the wild or get bitten.

As a general rule of thumb, never pick up snakes in the wild.

• Do not approach or try to handle the snake. Both species can move quickly. The Bamboo Pit Viper is venomous and can bite if threatened.
• Stay calm and keep a safe distance. Most snakes will try to avoid humans if left undisturbed.
• Even venomous snakes do not want to bite you. The Bamboo Pit Viper would rather use its venom to catch prey.
• Avoid sudden movements near the snake to prevent provoking it.
• Remember: snakes are an important part of the ecosystem and should be respected, not harmed.

1. If you are bitten by a snake in Hong Kong, stay calm and move away from the snake immediately to avoid further bites.
2. Call emergency services by dialing 999 right away, as timely treatment is crucial.
3. While waiting for help, keep the bitten limb as still as possible and positioned lower than the heart to slow venom spread.
4. Remove any tight clothing or jewelry near the bite to prevent swelling complications. Gently clean the wound with water, but do not cut, suck, or apply a tourniquet to the bite area.
5. If you can safely do so, try to remember or photograph the snake’s appearance to assist doctors in identifying the species and providing appropriate treatment.

Snakebites from the Bamboo Pit Viper require urgent hospital care, but fatalities are rare with prompt medical attention. The last recorded snakebite death in Hong Kong was in 1995.

1. If your dog is bitten by a snake in Hong Kong, treat it as a medical emergency and seek veterinary care immediately.
2. Keep your dog as calm and still as possible to slow the spread of venom, and avoid any attempts to apply tourniquets or manipulate the bite area, as these can worsen the injury.
3. If it’s safe, try to take a photo or note the snake’s appearance to help vets identify the species and provide the correct antivenom.
4. Transport your dog quickly to a veterinary hospital that stocks snake antivenom, such as CityU VMC (24-hour service), which are equipped to handle venomous snakebites.
5. Watch for symptoms like swelling, pain, weakness, or paralysis, and inform the vet immediately so they can prepare antivenom and supportive care.

Here is a list of vets that carry antivenom.

Appearance:

Bright green coloration above, with a yellow or whitish underside. Triangular-shaped head covered in many small scales. The head is distinct from the neck, which is thin and obvious. Males will usually have a white band of scales around the lip area that runs down the entire body.

Eyes:

Orange-yellow or red eyes with vertical slit pupils (if the pupils are dilated in light, they can look more rounded at first glance)

Tail:

The very end of the tail has a distinctive reddish-brown or orange tint, often streaked or mottled.

Behavior:

Primarily nocturnal and ambushes prey using heat-sensing pits located below the eyes. It tends to remain still when disturbed, relying on camouflage.

Size:

Typically 50–90 cm (1’8” to 2’11”), with females larger than males.

Venom:

The venom is a hemotoxin that causes severe pain, swelling, and tissue damage. While rarely fatal to healthy adults, bites require urgent medical attention. The Bamboo Pit Viper is responsible for the majority of snakebite cases in Hong Kong - up to 90% in total.

Habitat:

Found in forests, mountains, wetlands, and a variety of green spaces across Hong Kong. Often in trees and bushes because of their arboreal (climbing in trees) nature.

Rarity:

Common, and widespread throughout Hong Kong

Appearance:

Bright green body with a more elongated, slender head and larger scales on the head. The head blends smoothly into the neck, with no obvious narrowing.

Eyes:

Large eyes with round pupils, reflecting its diurnal (daytime) activity.

Tail:

Uniform green coloration from body to tail, with no orange or red tint.

Behavior:

Active during the daytime, generally docile and quick to flee when encountered. It feeds mainly on earthworms and insect larvae.

Size:

Usually under 1 meter in length, slender-bodied.

Venom:

Completely harmless to humans, with no venom.

Habitat:

Prefers heavily vegetated areas, often found on the ground or roosting in trees and bushes at night.

Rarity:

Common, and widespread throughout Hong Kong

Head Shape:

BPV: Triangular, distinct from neck

GG: Elongated, smoothly blends with neck

Scales:

BPV: Many small scales

GG: Larger, fewer scales

Eyes:

BPV: Orange-yellow/red with vertical slit pupils

GG: Large with round pupils

Tail color:

BPV: Reddish-brown or orange tint

GG: Uniform green

Venom (Do Not Test the Difference This Way):

BPV: Venomous, painful bite
GG: Non-venomous, harmless

Activity period:

Nocturnal (active at night)

Diurnal (active during the day)

*You can still see nocturnal snakes during the day and vice versa

If you see a green snake in Hong Kong, use the above features to identify it and appreciate it from a safe distance. Avoid killing snakes out of fear. In Hong Kong, the Greater Green is often mistaken for the Bamboo Pit Viper and killed as a result. Neither deserves to be harmed, as they both play a vital role in maintaining Hong Kong's diverse ecosystem.

While the Bamboo Pit Viper is venomous and should be treated with caution, it is generally not aggressive unless provoked. Most bites occur when people accidentally step on or handle the snake.

By knowing the key differences between the Bamboo Pit Viper and Greater Green, you can safely enjoy Hong Kong’s rich natural spaces, and hike without unnecessary risk.

For detailed information on all of Hong Kong's snakes, this is a great resource.