Dendrelaphis ngansonensis
Silhouette: Alex Slavenko · PhyloPic
In 3 days ~70% in a week ~90%
Dendrelaphis ngansonensis, commonly known as either the Nganson bronzeback or Nganson bronzeback tree snake, is a species of snake in the family Colubridae, sound in Southeast Asia. The species name ngansonensis is named after the type locality of the Ngân Sơn district of Tonkin, North Vietnam.
Dendrelaphis ngansonensis belongs to the genus Dendrelaphis, which contains 48 other described species. D. ngansonensis is most closely related to Dendrelaphis cyanochloris, and together the two might form a species complex.
Dendrelaphis is one of five genera belonging to the vine snake subfamily Ahaetuliinae, of which Dendrelaphis is most closely related to Chrysopelea, as shown in the cladogram below: The species is found in Vietnam, Laos, Thailand, Cambodia, and southwestern China (Yunnan). Dendrelaphis ngansonensis is an arboreal snake that occurs in both primary and secondary forests. It preys upon small vertebrates. It has been found to be both diurnal and nocturnal, and has oviparous reproduction. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cuc Phuong National Park | 🇻🇳 Vietnam | |
| 2 | Khao Yai National Park | 🇹🇭 Thailand | |
| 3 | Cat Tien National Park | 🇻🇳 Vietnam |
Possible
About 30% of wildlife watchers report a Vietnamese Bronzeback sighting in Cuc Phuong National Park on a given day, based on 8 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 9th most-seen of the 16 reptiles we can rate there. Over three days the chance rises to about 70%, and over a week to about 90%, if each day is a fresh chance.
September
In that month about 60% of wildlife watchers report a Vietnamese Bronzeback in Cuc Phuong National Park on a given day, against about 10% in June, August and October–December, the lowest months. That is one of Cuc Phuong National Park's wettest months, with about 330 mm of rain against 40 mm in December.
Between 5 and 8 am
Across all the parks we cover, that three-hour window holds the most Vietnamese Bronzeback sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 3 parks where we can rate Vietnamese Bronzeback sightings, Cuc Phuong National Park has the highest daily chance: about 30%. Next come Khao Yai National Park (Thailand, about 20%) and Cat Tien National Park (Vietnam, about 10%).
Same family: Colubridae
The closest relatives of the Vietnamese Bronzeback that you can see in Cuc Phuong National Park (family Colubridae, Colubrid Snakes) are Oriental Whipsnake (about 50%), North China Green Snake (about 50%) and Guangxi cat snake (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Vietnamese Bronzeback is recorded against all the reptiles logged in Cuc Phuong National Park (8 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.
