Family : NATRICIDAE
Species : Rhabdophis siamensis
Maximum Size : 130 cm

This is a wide-ranging species of lowland and lower montane forests up to elevations of around 1800 metres. Like other keelbacks it is more commonly encountered on the ground near small waterbodies, such as ponds and streams. It may also ascend into low vegetation to rest.

Its diet comprises aquatic vertebrates such as frogs, tadpoles and fishes.

This is a long, slender snake with head slightly larger than the body, and large eyes.

The specimen illustrated here is a juvenile with typical patterning and colouration comprising a grey head, dark grey nape, and yellowish-orange dorsum which gradates into an olive-brown body adorned with regular darker markings. Below the eye is a dark bar. 

Adults have less complex patterning; the body is olive-brown (either plain or with yellow and black markings), and this gradates into red and yellow at the nape and head.

Rhabdophis siamensis occurs in Myanmar, Thailand, Vietnam, Cambodia and Laos. Outside the region its range extends to parts of southern China.

Figs 1 and 2 : Images of a Red-necked Keelback (juvenile) photographed at Bang Sare, Sattahip, Thailand.  Photos thanks to Ray Hamilton.

Fig 3 : Example from Kaeng Krachan National Park, Thailand consuming a frog.  Photo thanks to Charles Currin.


References :

Das, I., 2010. A Field Guide to the Reptiles of South-east Asia. New Holland Publishers (UK) Ltd.