Ptyas korros
Silhouette: Alex Slavenko · PhyloPic
In 3 days ~40% in a week ~70%
Ptyas korros, commonly known as the Chinese rat snake or Indo-Chinese rat snake, is a species of colubrid snake endemic to Southeast Asia. Snout obtuse, projecting; eye very large. Head broader than neck. Rostral visible from above; internasals shorter than the prefrontals; frontal as long as its distance from the tip of the snout or a little longer, as long as the parietals; two or three loreals; a large preocular, sometimes touching the frontal; a small subocular below; two postoculars; temporals 2 + 2; eight upper labials, fourth and fifth entering the eye; five lower labials in contact with the anterior chin-shields, which are shorter than the posterior.
Dorsal scales smooth or feebly keeled on the posterior part of the body, in 15 rows at midbody; ventrals 160–177; anal divided; sub-caudals 122–145. Brown or olive above; the scales on the posterior part of the body and on the tail often yellow and edged with black. Lower surface yellow. Young specimens with transverse series of round whitish spots or with narrow yellow transverse bars.
Length of head and body 1,080 mm (43 in); tail 700 mm (28 in). Nepal, Myanmar; Cambodia, China (Zhejiang... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cat Tien National Park | 🇻🇳 Vietnam | |
| 2 | Khao Luang National Park | 🇹🇭 Thailand | |
| 3 | Khao Sok National Park | 🇹🇭 Thailand | |
| 4 | Khao Yai National Park | 🇹🇭 Thailand | |
| 5 | Kaeng Krachan National Park | 🇹🇭 Thailand | |
| 6 | Doi Inthanon National Park | 🇹🇭 Thailand |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Dong Tam Snake Farm | 🇻🇳 Vietnam | |
| 2 | Siam Serpentarium | 🇹🇭 Thailand | |
| 3 | Snake Farm of Queen Saovabha Memorial Institute | 🇹🇭 Thailand | |
| 4 | Pata Zoo | 🇹🇭 Thailand |
Possible
About 20% of wildlife watchers report a Chinese Ratsnake sighting in Khao Yai National Park on a given day, based on 21 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 23rd most-seen of the 46 reptiles we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
November
In that month about 30% of wildlife watchers report a Chinese Ratsnake in Khao Yai National Park on a given day, against under 5% in March and August, the lowest months. That is one of Khao Yai National Park's driest months, with about 60 mm of rain against 330 mm in September.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Chinese Ratsnake sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
Among the best
Of the 6 parks where we can rate Chinese Ratsnake sightings, Khao Yai National Park ranks 4th at about 20%, level with the leaders once rounded. The best odds are in Cat Tien National Park (Vietnam, about 20%), Khao Luang National Park (Thailand, about 20%) and Khao Sok National Park (Thailand, about 20%).
Same family: Colubridae
The closest relatives of the Chinese Ratsnake that you can see in Khao Yai National Park (family Colubridae, Colubrid Snakes) are Oriental Whipsnake (about 30%), Yellow-Spotted Keelback (about 20%) and Vietnamese Bronzeback (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Chinese Ratsnake is recorded against all the reptiles logged in Khao Yai National Park (21 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.
