Colubridae-3-H-L-Check list snakes northern Thailand

Colubridae-3-H-L-Check list snakes northern Thailand: snakes in the genera Liopeltis (ring necks) and Lycodon (wolf snakes).

Liopeltis frenatus, the Stripe-necked Snake. This snake is a recent (2018) addition to the snake fauna of Thailand. It is known from only one individual that was spotted in lower submontane forest at an elevation of 1700 m in Nan province. Throughout its range, which includes northeastern India, and northern Myanmar, Laos and Vietnam, it is a rare species that only occurs at high elevations. Pictures©SJON HAUSER, More about this record in  the April 2018 issue of  Tropical Natural History  https://tci-thaijo.org/index.php/tnh/issue/archive  (PDF can be downloaded). 
Liopeltis spec.

Lycodon capucinus, the House Wolf Snake (above) is a brown snake with a pale yellow reticulation that can reach a length of 70 cm. Usually a collar is distinct at the back side of the head. The belly is white. It is a common snake in deciduous forest throughout the region. A. An adult individual on wet road at night, Tha Song Yang District, Tak. B. A juvenile specimen from Ko Samui, Surat Thani, South Thailand (Thanks to Johan van Rooijen for this picture!). C. An individual from Pang Mapha District, Mae Hong Son (Thanks to Little Eden for this picture!). D. Same specimen as in A.

Lycodon fasciatus, the Mountain Wolf Snake (above) can reach a length of 80 cm. This black wolf snake tells itself apart from most congeners with its about 45 light bands with very irregular, zigzagging borders (A, B, C, G). These pale bands are usually pale pink with many tiny brownish streaks (A, B, G), but in juveniles they are white with many tiny greyish streaks (C). The blacks bands continue over the white ventral side (D).  7-9 central rows of dorsals are distinctly keeled (G). The head is moderately distinct from the neck (B, C, E). The hemipenes are heavily spined (F). This snake is quite common in evergreen forest above 900 m throughout the northern region.
Localities of the specimens illustrated: A. Mae Taeng District, Chiang Mai. B. Doi Suthep, Mueang District, Chiang Mai. C. Mueang Pan District, Lampang. D. Chiang Dao District, Chiang Mai. E-F. Mae taeng District, Chiang Mai. G. Doi Suthep, Mueang District, Chiang Mai.

Lycodon laoensis, the Lao Wolf Snake (above) is a shining black snake with yellow bands that reaches a length of 600 cm. The belly is white. It is common in deciduous forest and cultivated land at elevations below 700 m throughout the region. A & E. A specimen from Mueang District, Chiang Mai. B, C & D. An individual from Mae Taeng District, Chiang Mai.

Lycodon subcinctus, the Malayan Banded Wolf Snake (above) is a slender, black-and-white banded snake that reaches a length of 90 cm. In aldult specimens the white bands on the posterior half of body and the tail usually fade away due to deposition of black grains. In northern Thailand is a locally common snake in deciduous forest and cultivated land at elevations below 600 m. 1-2. A specimen from Mueang District, Chiang Mai. 3-4. A subadult from Chat Trakan District, Phitsanulok.