Gonyosoma oxycephalum
Silhouette: Alex Slavenko · PhyloPic
In 3 days ~50% in a week ~80%
Gonyosoma oxycephalum, known commonly as the arboreal ratsnake, the red-tailed green rat snake, and the red-tailed racer, is a species of snake in the family Colubridae. The species is endemic to Southeast Asia. It was first described by Friedrich Boie in 1827.
G. oxycephalumm is found in Indonesia (Bangka, Belitung, Java, Kalimantan/Borneo, Karimata, Legundi, Lombok, Mentawai islands, Natuna islands, Nias, Panaitan, Riau archipelago, Sebuku, Sumatra, Tambelan archipelago), Malaysia (Malaya and East Malaysia, Pulau Tioman ?),
Singapore Island, Penang Island, India (Andaman Islands), Myanmar, Thailand (incl. Phuket), Cambodia, Laos, Vietnam, Philippine Islands (Balabac, Bohol, Catanduanes, Lubang, Luzon, Negros, Palawan, Sulu Archipelago, Panay).
The type locality is Indonesia: Java (F. Boie, 1827). G. oxycephalum is a robust powerful snake, with wide smooth scales on its belly that are ideal for climbing trees and across branches. It has smaller, smooth scales on its back, which is usually bright green or light green and may have a black net-like pattern. A gray-colored morph with a yellow head exists in Panay, in the Philippines.
As some of its... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Khao Sok National Park | 🇹🇭 Thailand | |
| 2 | Taman Negara National Park | 🇲🇾 Malaysia | |
| 3 | Danum Valley Conservation Area | 🇲🇾 Malaysia | |
| 4 | Sepilok | 🇲🇾 Malaysia | |
| 5 | Khao Yai National Park | 🇹🇭 Thailand | |
| 6 | Gunung Leuser National Park | 🇮🇩 Indonesia | |
| 7 | Kinabalu Park | 🇲🇾 Malaysia | |
| 8 | Cat Tien National Park | 🇻🇳 Vietnam | |
| 9 | Kinabatangan Wildlife Sanctuary | 🇲🇾 Malaysia | |
| 10 | Kaeng Krachan National Park | 🇹🇭 Thailand |
Possible
About 20% of wildlife watchers report a Red-tailed Green Ratsnake sighting in Danum Valley Conservation Area on a given day, based on 12 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 15th most-seen of the 35 reptiles we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
December
In that month about 50% of wildlife watchers report a Red-tailed Green Ratsnake in Danum Valley Conservation Area on a given day, against under 5% in February, April and June–September, the lowest months.
Between 4 and 7 am
Across all the parks we cover, that three-hour window holds the most Red-tailed Green Ratsnake sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 10
Of the 10 parks where we can rate Red-tailed Green Ratsnake sightings, Danum Valley Conservation Area ranks 3rd at about 20%. The best odds are in Khao Sok National Park (Thailand, about 30%) and Taman Negara National Park (Malaysia, about 30%).
Same family: Colubridae
The closest relatives of the Red-tailed Green Ratsnake that you can see in Danum Valley Conservation Area (family Colubridae, Colubrid Snakes) are Gray Bronzeback (about 40%), Triangle Keelback (about 30%) and Paradise Flying Snake (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Red-tailed Green Ratsnake is recorded against all the reptiles logged in Danum Valley Conservation Area (12 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.
