Daboia siamensis
Silhouette: Steven Traver · PhyloPic
In 3 days ~70% in a week >90%
Daboia siamensis (Common name: eastern Russell's viper, Siamese Russell's viper, more) is a viper species which is endemic to parts of Southeast Asia, southern China and Taiwan. It was formerly considered to be a subspecies of Daboia russelii (as Daboia russelli siamensis), but was elevated to species status in 2007.
Dorsally, the color pattern is the same as that of D. russelii, except that the color is more grayish or olive, with small spots between the large spot rows. The venter is suffused with gray posteriorly. Common names for D. siamensis include eastern Russell's viper and Siamese Russell's viper.
Previously, other common names were used to describe subspecies that are now part of the synonymy of this species: Indonesian Russell's viper for "limitis", and Formosan Russell's viper for "formosensis". Daboia siamensis is found in Myanmar, Thailand, Cambodia, China(Guangxi Guangdong), parts of India, Taiwan, Nepal and Indonesia (Ende, Bima-Sumbawa, Flores, east Java, Komodo, Lomblen Islands).
Brown (1973) mentions that D. siamensis can also found in Vietnam, Laos and on the Indonesian island of Sumatra. Ditmars (1937)... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Komodo National Park | 🇮🇩 Indonesia |
More parks will be added in future updates.
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Angkor Wildlife & Aquarium | 🇰🇭 Cambodia | |
| 2 | Siam Serpentarium | 🇹🇭 Thailand | |
| 3 | Snake Farm of Queen Saovabha Memorial Institute | 🇹🇭 Thailand |
Likely
About 40% of wildlife watchers report a Siamese Russell's Viper sighting in Komodo National Park on a given day, based on 16 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 7th most-seen of the 19 reptiles we can rate there. Over three days the chance rises to about 70%, and over a week to over 90%, if each day is a fresh chance.
February and March
In those months about 50% of wildlife watchers report a Siamese Russell's Viper in Komodo National Park on a given day, against under 5% in July and December–January, the lowest months. Those are among Komodo National Park's wettest months, with about 170 mm of rain a month against 10 mm in August.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Siamese Russell's Viper sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is seen both by day and at night.
Only Komodo National Park, in our data
Komodo National Park is the only park on Wallace's Line with enough records to rate Siamese Russell's Viper sightings: about 40% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Siamese Russell's Viper is recorded against all the reptiles logged in Komodo National Park (16 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
