Thai National Parks

Snakes of Thailand

Species of Thailand

Red-tailed tree snake

In Thai: งูเขียวกาบหมาก

Binomial name: Gonyosoma oxycephalum, Heinrich Boie, 1827

The red-tailed green ratsnake (Gonyosoma oxycephalum, also known as arboreal ratsnake and red-tailed racer) is a species of snake found in Southeast Asia.


It is a robust snake with powerful, smooth scales on its belly that is ideal for climbing trees and across branches. It has smaller, smooth scales on its back that is usually bright green or light green and may have black net-like pattern. A gray-colored morph with a yellow head exists in Panay, in the Philippines.

As its name indicates, the snake has a green body with a red tail but is usually brown. It also has a dark line horizontally across its eye. On the sides of its black tongue there may be a Brown and blue colour. The top of the head maybe dark green, yellow-green or yellow in colour.

The female can reach a length of up to 2.4 m (almost 8 feet), while the male is generally a little bit smaller but brighter in coloration. Its average life span in captivity is 20 years. It reaches sexually maturity at 4 years of age, and its eggs have a hatching time from 13 to 16 weeks. The female lays on average between 3 and 8 eggs usually between September and January and the hatchlings are about 45 cm (18 inches) long.


The red-tailed green ratsnake lives and spends its life in the trees and in cavities in trees. It seldom descends to the ground. When the snake is stressed, it may inflate a bag of air in its neck, making it appear larger in size.

In captivity, it has quite the 'attitude' and may strike at or bite an unwary handler. It's temperament can be unpredictable and may change from time to time but an individual may become tame through proper handling.


It feeds almost exclusively on birds, bird eggs and bats. It catches them in mid-air while hanging amongst branches. In captivity, it can be trained to feed on rodents such as mice and rats.


  • 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 (= Burma),
  • Thailand (incl. Phuket), Cambodia, Laos, Vietnam,
  • Philippine Islands (Balabac, Bohol, Lubang, Luzon, Negros, Palawan, Sulu Archipelago, Panay)

Type locality Indonesia: Java (Boie, 1827)

This article uses material from Wikipedia released under the Creative Commons Attribution-Share-Alike Licence 3.0. Eventual photos shown in this page may or may not be from Wikipedia, please see the license details for photos in photo by-lines.

Scientific classification

Gonyosoma oxycephalum

Common names

  • German:
    • Spitzkopfnatter
    • Rotschwanznatter
  • English:
    • Red-tailed tree snake
    • Red-tailed racer
    • Red-tailed green ratsnake
  • Thai: งูเขียวกาบหมาก


  • Gonyosoma floweri, Tanya Chan-Ard et al. (2015)
  • Gonyosoma oxycephalum, Chen et al. (2014)
  • Gonyosoma oxycephalum, Maren Gaulke (2011)
  • Gonyosoma oxycephala, Frank T. Burbrink & R. Lawson (2007)
  • Elaphe oxycephala, R.C. Sharma (2004)
  • Gonyosoma oxycephala, Maren Gaulke (2001)
  • Gonyosoma oxycephalum, Merel J. Cox et al. (1998)
  • Gonyosoma oxycephalum, Ulrich Manthey & Wolfgang Grossmann (1997)
  • Elaphe oxycephala, Klaus-Dieter Schulz (1996)
  • Gonyosoma oxycephalum, Ludwig Trutnau (1986)
  • Gonyosoma oxycephalum, Herndon Glenn Dowling (1958)
  • Elaphe oxycephala, Malcolm Arthur Smith (1943)
  • Elaphe oxycephala oxycephala, Sackett (1940)
  • Gonyosoma oxycephala, Thomas Barbour (1912)
  • Elaphe oxycephala, Griffin (1909)
  • Coluber oxycephalus, George Albert Boulenger (1894)
  • Coluber oxycephalus, George Albert Boulenger (1890)
  • Gonyosoma oxycephalum, Ferdinand Stoliczka (1870)
  • Aepidea robusta, Edward Hallowell (1861)
  • Coluber jansenii nec Gonyosoma jansenii, Pieter Bleeker (1858)
  • Gonyosoma oxycephalus, Pieter Bleeker (1857)
  • Alopecophis chalybeus, John Edward Gray (1849)
  • Herpetodryas oxycephalus, Hermann Schlegel (1837)
  • Gonyosoma viride, Johann Georg Wagler (1828)
  • Coluber oxycephalus, Friedrich Boie (1827)
  • Elaphe oxycephala, Friedrich Boie (1827)

Conservation status

Least Concern (IUCN3.1)

Least Concern (IUCN3.1)

Range Map

Distribution map of Red-tailed tree snake, Gonyosoma oxycephalum in Thailand
Range map of Gonyosoma oxycephalum in Thailand