Gongylosoma scripta—the little known Indo-Chinese Ground Snake

Gongly-01-DSC01300bThe genus Gongylosoma (Ground snakes) contains a number of rather small, inconspicuous snakes of which little is known. They are related to the genus Liopeltis and, in a lesser degree, to Sibynophis.  They are slender snakes with a long tail, total length rarely more than 50 cm. A character that distinguishes them from most other snakes is their low number of thirteen rows of dorsal scales at mid-body. Four species are known from Southeast Asia (1). One species is recorded in northern Thailand, Gongylosoma scripta.

Gongylosoma scripta
English name: Indochinese Ground Snake

Gongly-02■ (left): An adult male from Mae Wong National Park, Kamphaeng Phet. ■ (right): A juvenile from the mountains of Tak’s Umphang District.

This is a slender, brown snake with a long tail that superficially resembles the Common Blackhead (Sibynophis collaris). The central part of the body has a little more reddish-brown hue than the rest. There is a faint lateral line. The head is distinct from the neck, dark brown and bordered in the neck by a narrow, indistinct orange-brown collar. On the forepart of the body are two rows of little dark, widely separated dots. The two rows are separated by three central rows of dorsal scales. These characters are strikingly similar to the Common Blackhead, however, the latter has only one row of dark dots on the vertebral ridge.

Most distinctive for the species is a white pattern on the side of the head resembling the letter E laying on its back—two of its arms are bordering the eye, the third arm is covering most of the posterior temporal scales (see pictures below). In the Common Blackhead such an ornamentation is absent.
The underside of the tail and the rear of the belly are yellow, whereas the remaining forepart of the belly is white (all white in the Common Blackhead). The morphology of the hemipenes is also distinct: short, bud-shaped with a depression on the apex and the base covered with many small spines (in the Common Blackhead there a 3-4 very large spines).

Gongly-03■ (left): The upper side of the head of a juvenile from Umphang District. ■ (right): The right side of the head of an adult from Umphang District.

Little is known about this snake. It is active during the day and seems to have a gentle disposition. Its feeding habits are perhaps similar to the Common Blackhead’s, preying on small skinks and arthropods.
In northern Thailand one will not often spot this little snake. I came across it in dense hill evergreen forest in the mountains of the Umphang Wildlife Sanctuary (Tak Province) and Mae Wong National Park (Kamphaeng Phet Province) at elevations above 1000 m. I also spotted it in a similar habitat in the Khao Yai National Park (Northeast Thailand) at about 900 m. It also occurs in southern Thailand and peninsular Malaysia.
Three related species are known from southern and southeastern Thailand, peninsular Malaysia and much of insular Southeast Asia.
Probably the specimens of G. scripta from Kamphaeng Phet and Tak province are the most northern representives of the genus.

Gongly-04■ (left): The belly of a roadkill from Mae Wong National Park in Kamphaeng Phet Province, showing the long tail and the yellow underside of the tail and rear end of the belly. ■ (center): The hemipenes of the same specimen. ■ (right): Map of northern Thailand showing where the species is known to occur.

Notes:
1. Smith, Malcolm A. 1943. The fauna of British India, Ceylon and Burma, including the whole of the Indo-Chinese subregion. Reptilia and Amphibia. Vol. III, Serpentes. London: Taylor & Francis; Das, Indraneil, 2010. A Field Guide to the Reptiles of Thailand and South-East Asia. Asia Books, Bangkok: p. 280; Das, Indraneil, 2012. A Naturalist’s Guide to the Snakes of Thailand and Southeast Asia. John Beaufoy Publ., Oxford (UK): p. 41.