Yunnan reed snake

conservation

Conservation status Calamaria yunnanensis has been recorded from two localities in southern Yunnan Province China based on a total of six to seven known specimens. The full extent of this species distribution in Yunnan Province is unknown. I recommend that C. yunnanensis be listed as ‘ Data Deficient’ following the IUCN’s Red List categories (IUCN 2019).

description

Description of the referred specimen Male (maturity unknown) in good condition, with one incision at the tail base and another along the posterior portion of body. SVL 226 mm, TailL 20 mm, TotalL 246 mm, HeadL 7.4 mm (6.4 mm measured from the parietal tip), HeadW 4.0 mm, SnL 2.6 mm, SnW 2.0 mm, EyeD 1.0 mm, NarEye 1.5 mm, IOD 3.1 mm. Body height at midbody 3.5 mm, at tail base 3.3 mm; eye – mouth distance 0.8 mm; rostral scale width 0.9 mm, height 1.1 mm; prefrontal scale length 1.8 mm, suture 1.0 mm; frontal scale length 2.4 mm, width 1.9 mm; parietal scale length 3.3 mm, suture 1.8 mm. TailL / TotalL 0.081; HeadL / W 1.6; HeadL / SVL 2.83; SnL / HeadL 0.41; EyeD / SnL 0.38; NarEye / SnL 0.58; SnW / IOD 0.66; IOD / HW 0.76. Body elongate and vermiform, round in cross section; tail thick, roughly equal in diameter to rest of body; posterior portion of tail slightly tapering, then abruptly tapering at the tip, which appears obtusely pointed in dorsal view (weakly acute), round in lateral view; head sub-oblong in dorsal view, indistinct from neck; snout blunt, weakly depressed posteriorly; nostrils small and elliptical; eyes small, round, diameter larger than eye – mouth distance; pu

diagnosis

Diagnosis A species of Calamaria distinguished from all other members of the genus found in mainland Southeast Asia by having the following combination of morphological characters: (1) rostral scale wider than high; (2) portion of rostral scale visible from above less than half the length of the prefrontal suture; (3) six scales and shields surrounding the paraparietal scale; (4) absence of a preocular scale; (5) four supralabials, with the second and third touching the eye; (6) five or six infralabials, the first pair separating the mental scale from the anterior chin shields; (7) 167 – 184 ventrals in males, 199 in female, three gular scales; (8) 15 – 20 subcaudals in males, 19 in female, all paired; (9) dorsal colour pattern variable, usually bluish-grey or olive-brown with indistinct dark brown longitudinal stripes across each dorsal scale row forming a network-like pattern, sometimes restricted to the flanks; (10) ventral surface red or yellow usually with dark brown margins on the ventral scales and a black midventral stripe under the tail, completely immaculate in some specimens; and (11) a light yellow nuchal collar posterior to the head usually present, absent in some spec

distribution

Distribution and natural history So far, C. yunnanensis has been collected from three localities in south-central Yunnan Province, China (Figure 7). The type locality, Jingdong Autonomous County, is situated 1100 – 1200 metres above sea level, while the locality of ROM 41547 was at 1270 metres above sea level. The type specimen was found underneath a rock in a forested montane valley. The photographed individual in Yang and Zheng (2018) was located approximately 60 km north-west of the type locality in Nanjian Yi Autonomous County, Dali, Yunnan Province, China (24 ° 48 ʹ 09.3 ” N, 100 ° 32 ʹ 58.5 ” E; ~ 1700 metres above sea level). It was found on 27 July 2011 at night between 17: 00 and 18: 00 UTC, attempting to climb across a rock along the road’s shoulder (Chung-Wei You, pers. comm). The surrounding habitats in these localities include a mix of tropical montane deciduous forests near Simao, and montane evergreen broadleaf forests near Nanjing Yi and Jingdong Autonomous Counties. The climate in these regions is monsoon influenced and considered humid subtropical (Cwa) or subtropical highland (Cwb) according to the Köppen Classification (Peel et al. 2007). Besides this informatio