Trimeresurus popeiorum – Pope’s Pit Viper
Pope’s Pit Viper (Trimeresurus popeiorum) male in ambush in Doi Luang national park, Thailand
The Trimeresurus popeiorum is known as the Pope’s Pit Viper. This common green viper with red eyes occurs in North & Northwest Thailand mostly in evergreen forest and at medium to high elevation.
facts
| Dangerous? | Potentially dangerous; front-fanged, foldable hollow fangs, potent venom; these snakes rely on their camouflage so are not likely to flee. Which means, in the unfortunate case you don’t see it, but unknowingly grab it, it may decide to bite. |
| Venom | Some sources state neurotoxic, but most pit vipers seem to be haemotoxic and in reports about bites from this species the symptoms suggest it is primarily haemotoxic |
| Length | about 80 – 90cm |
| Diet | Frogs, rodents, lizards & birds |
| How easy to find | Quite easy to find in right conditions and habitat. |
| Best time of year | Wet season is best, but also humid days in the dry season. |
| Best time of day | Nocturnal, but we have found them in daytime as well. Though some seem to hide in daytime and only show up once darkness falls. |
| Threats | No main threats |
| Notes: | DNA research has indicated that the highly similar looking population in the Tenasserim range is a separate species. |
Pope’s Pit Viper (Trimeresurus popeiorum) male head shot in Doi Luang national park, Thailand
Description
Both sexes of the Trimeresurus popeiorum have deep red eyes (except in the juveniles) and a deep red mottled tail. The females are bright lime green with a white ventral line. Males are more grass green usually with a red and white ventral line and a red and white streak starting from the eye.
To be continued…
Pope’s Pit Viper (Trimeresurus popeiorum) juvenile female in situ in Doi Luang national park, Thailand
Similar-looking species
There are various green pit viper species with similar looks, keeping them apart can be tough in certain cases.
To be continued…
- Trimeresurus cf. popeiorum – Pit Viper from the Tenasserim rangeNo clear visible way to distinguish. Maybe a future publication will provide more details on morphological differences.
Pit Viper (Trimeresurus cf. popeiorum) male from Kaeng Krachan national park, Thailand
- Trimeresurus gumprechti – Gumprecht’s Pit Viper
Coloration is mostly the same, though females tend to have golden eyes in T. gumprechti. The males have red eyes just like the Trimeresurus popeiorum, but the black interstitial skin is the main key to tell these apart.
Pope’s Pit Viper (Trimeresurus popeiorum) juvenile female head in Doi Luang national park, Thailand
Behaviour
Nocturnal and arboreal.
To be continued…
Pope’s Pit Viper (Trimeresurus popeiorum) male in situ in Doi Luang national park, Thailand
Range & habitat
The Pope’s Pit Viper occurs in North and Northwest of Thailand and is normally found at higher elevations. In most of its range above 800m asl, but it might be found at lower elevation especially in the South of its range. They prefer evergreen forests, usually in quite densely vegetated areas. We have found them in ambush position on the leaf litter on slopes, but in general they seem to prefer to position themselves on twigs/ branches from just off the ground up to 4 – 5m high.
Taxonomy
The Trimeresurus popeiorum honors the American herpetologist Clifford H. Pope. And in the past even the genus was named after the same herpetologist as Popeia popeiorum which in recent publications is used as a subgenus Trimeresurus [Popeia] popeiorum.
Sometimes the name is spelled as T. popeorum
Pope’s Pit Viper (Trimeresurus popeiorum) male in Doi Luang national park, Thailand
How to find this species in Thailand?
This species is easiest found in the dark. The green body, even more so the ventral surface, pop out from the green foliage in the light of a flashlight. In most cases these vipers won’t move much, so usually you will find them in ambush position. The large majority we have found from just above ground level to about 2m high, but occasionally they stay on the forest floor or higher up in trees/ bamboo. Close to water sources seems to be best.
