Thailand has approximately 60 snake species that are considered venomous and potentially dangerous to human beings. Below are photos, videos, and links to more information on some of the most common snakes that fit this description.
Calloselasma rhodostoma. Malayan Pit Viper.
Very dangerous. Potentially deadly. This snake is active at night (nocturnal) and during dawn and dusk (crepuscular) and during rainy or very overcast weather. I have found them in the lowlands at sea level, and as high as 500 meters here in Thailand.
The following is a video showing the color variations for the Malayan pit viper. These are all from Southern Thailand, so depending where you are in the country, yours may look similar or slightly different. The very triangle head shape and triangle pattern on the top back will not change.
1 Video – Malayan Pit Viper (Calloselasma rhodostoma) Color Variations:
Naja kaouthia. Monocled Cobra.
Very dangerous and potentially deadly. This snake is most active during the daytime, but is also sometimes found to be active at night. During some of the hottest days they can be seen regularly crossing the roads. Around 3 pm. seems to be a very active time for them.
2. Jackie, a Burmese National, Catching a Monocled Cobra in a Local’s Yard:
3. Tom (Dtom, Dtammy) After Bitten in Thigh by Monocled Cobra:
Rhabdophis subminiatus. Red-necked Keelback.
This colorful snake was often kept as a pet and hand-held before it was realized they pack a deadly bite. Their venom is as strong as a banded krait on the LD scale. They are active during daylight hours and are commonly found across Thailand.
Keep in mind, the smaller the snake, generally the more quickly it can strike.
The oriental whip snake is a very common rear-fanged venomous snake found here in Thailand’s rain forests. You can find these snakes in the trees during the day, I have even seen them crossing my path twice on trips up a small local mountain in southern Thailand.
The beauty of these snakes is legend. There are green, yellow, or grey phases of this snake, all of which are spellbindingly beautiful. The juvenile whip snakes are often brown or yellow.
Ahaetulla prasina (Oriental Whip snakes)
Thai Language: ngoo kee-ow hoo-uh jing joke pa
Length: Up to 190 cm. Girth: Body is finger thin, tapering to a very thin pencil-width neck. The head is spear shaped and bright green.
Range: All over Thailand. The species ranges from India to China and throughout Southeast Asia.
Habitat: During the day you can find these snakes in trees and bushes usually. Occasionally they will be at ground level hunting frogs and small lizards. I have seen these snakes in all kinds of habitat, but usually in trees and leafy bushes. At night these snakes sleep in the same environment.
Active Time? Diurnal – active during the daylight hours.
Food: Frogs, small birds, small lizards.
Defensive Behavior: The oriental whip snake can spread it’s neck area to increase by double in size as a defensive technique designed to scare attackers. It is quite beautiful when either solid green, or with the green, white and black checkered pattern displayed in full defensive posture. Sort of comical is what the snake does with it’s tongue when molested. It sticks the tongue out and holds it there for some seconds, or minutes.
Venom Toxicity: Weak. Although this is considered to be a rear-fanged and venomous snake it is not very dangerous to humans due to it’s non-aggressive nature and weak venom characteristics. The venom would need to be injected into the wound with time – with a chewing motion. Not many people bitten are going to let a snake hang off them for any amount of time. Some do, and they may have severe complications and require hospitalization.
Offspring: In Thailand the Ahaetulla prasina can mate during either of two times. Usually between April and July, and then also between December and January. Gestation period: ~ 6 months. Number of births: 4-10. Lengths at birth of offspring: 400 – 500 mm.
Notes: These are wonderful little snakes to catch and let go. These snakes do not do well in captivity and many die within days of being kept in an enclosure. They are as beautiful as snakes get, but please resist the urge to capture one to keep as they are very sensitive and die easily.
We have not been bitten by these snakes, but in the wild when catching them they will attempt to strike at times. They are fast and have a short striking range. What is really amazing about these snakes is the way they effortlessly glide down a hill or through trees like on ice. They can climb extremely fast and disappear before you have a chance to grab them. See video below!
These snakes are not often confused with other snakes here in Thailand because they are quite distinctive. Their head is long and to a fine point. They are very thin at the neck before the head unless they have flared up in defense.
Length: Up to 130 cm (1.3 meters). Usually under 1 meter.
Range: Thailand and southeast Asia.
Notes: These snakes are commonly found near water, lakes, ponds, and in gardens. Recently a friend had one in his swimming pool in Krabi town, southern Thailand.
Active Time? Daylight hours. I’ve found them sleeping around 1 foot off the ground in bushes.
Food: Frogs, poisonous toads, and fish.
Defensive Behavior: Spread out the neck slightly to make themselves appear bigger. Not as dramatic as a cobra. Lift their head and neck off the ground 4-5 inches.
Some snakes of this species, and others in the genus Rhabdophis, have displayed a rather unique defensive behavior of exposing the back of their neck and secreting poison from their nuchal glands. This is not all that common, I for one have never seen this in the wild or with snakes in captivity and I’ve seen dozens of them.
One researcher, Kevin Messenger, claims that the R. subminiatus helleri he caught in Hong Kong actually sprayed a mist of the poison into the air from the back of the neck. Quite amazing, if true, right? Obviously more study is needed into the secret life of this fascinating snake. Other snakes in Rhabdophis genus with nuchal glands: R. nuchalis, R. tigrinus, R. nigrocinctus (in Thailand).
Here is an image of the snake expressing poison from the nuchal glands.
Here is the description in a scientific journal about Kevin’s encounter.
Venom Toxicity: LD50 is 1.29 mg/kg for intravenous injection (source). That is about the same rating as the very deadly “Banded Krait (Bungarus fasciatus)”. It was previously thought these snakes were harmless. Some kept them as pets and were bitten. In one case the snake was left to bite for two entire minutes before removing it from a finger.
Serious complications resulted requiring hospitalization and intensive care. Click for article. These snakes are rear-fanged and need to bite and hold on, or, repeatedly bite to have any effect on humans. Once they do either – there is the possibility of severe problems including renal failure and death. Recently a small boy of 12 years old was bitten by one he was keeping as a pet in Phuket, Thailand and he is currently being treated (11/5/10). Be very careful not be be bitten by these snakes. There is NO ANTIVENIN available yet for these snakes in Thailand. Scroll down for information about antivenin manufactured in Japan that may have some positive effect.
Another study in Japan ranked the venom as having an LD50 of 1.25 mg/kg for intravenous injection. (Japan Snake Institute, Hon-machi, Yabuzuka, Nitta-gun, Gunma-ken, Japan) V.1- 1969- Volume(issue)
In Japan they make limited amounts of antivenin, but it is specifically for their in-country use.
One WHO (World Health Organization) publication about the management of venomous snake bites in Southeast Asia mentions the antivenin for Rhabdophis tigrinus in Japan as having some effect on the venom of R. subminiatus. I am not sure if this is strictly for R. subminiatus found in Japan, or not. Worth a try though if you can get them to send you some antivenin. Otherwise, there is no other option – there is no monovalent antivenin specifically for R. subminiatus.
Japan Snake Institute
Nihon Hebizoku Gakujutsu Kenkyujo
3318 Yunoiri Yabuzuka
Yabuzukahonmachi Nittagun Gunmaken 379-2301
Tel 0277 785193 Fax 0277 785520 [email protected]
Yamakagashi (Rhabdophis tigrinus) antivenom. Also effective against rednecked keelback (R. subminiatus venom)
Update: The 12 year old boy bitten by the Rhabdophis subminiatus was treated for 2 weeks of intensive care, and released. He was bitten multiple times, the 2nd bite lasting over 20 seconds.
Offspring: I had a juvenile red-necked keelback I’ve taken photos and videos of and released into the wild. I cannot find anything much about offspring. Recently (mid-June) I found a DOR juvenile very recently hatched, so like most snakes in Thailand the time around June is when they are hatching out. The coloration of the juvenile is quite different from adults as you can see in the photo and video below.
Notes: These snakes can inflict a deadly bite when they are allowed to bite for longer than a couple of seconds. I know personally of two instances where a child was bitten for well over 20 seconds, and a man was bitten for about a minute. Neither wanted to hurt the snake to remove it forcibly, and both spent over a week in intensive care, with the possibility of renal failure and death. Do not play with these snakes. If you have one, do not free-handle it. Treat it like you would a pit viper or a cobra. The LD50 on this snake for intravenous was stated to be 1.29 mg/kg. That is VERY venomous.
As a precaution, any snake in the Rhabdophis genus should be treated with extreme caution. In Thailand we also have the diurnal Rhabdophis nigrocinctus, and Rhabdophis chrysargos, both of which may be able to inflict a medically significant bite if given the opportunity.