On the distribution of Cantor's Kukri snake Oligodon cyclurus (Cantor, 1839) (Squamata: Colubridae) from Nepal

The distribution of Cantor's Kukri Snake Oligodon cyclurus has been poorly documented in its geographic range from Bangladesh, Cambodia, China, India, Laos, Myanmar, Nepal, Thailand and Vietnam. We provide confirmed locality records with notes on some aspects of natural history information for O. cyclurus. Although the species is designated as Least Concern according to IUCN Red list of Threatened Species, the species is facing multiple threats like roadkills and vindictive killing. We suggest a more detailed inventory to better understand its biology, distribution patterns, population status and molecular identity to aid in a more comprehensive global conservation action.

The earlier records of the Cantor's Kukri snake, O. cyclurus from Nepal were either doubtful (see Kästle et al.; or mentioned its occurrence in Nepal without locality records (see Shrestha, 2001). Later, Pandey (2015) reported O. cyclurus in Nepal based on a photo voucher from South-eastern Nepal (Bhattarai et al., 2017b).
Here-in, we provide confirmed locality records and natural history observations of O. cyclurus from Nepal.

Material and Methods
We recorded two individuals of O. cyclurus from altered habitats: the first individual was recorded on 25 April 2019 as a road killed specimen during biodiversity assessment in the Pathari-Shanischare forest patch (26°39'39.17"N, 87°32'57.47"E) in Morang district (Fig. 1). The total length of the badly crushed individual was 690 mm, and we could not count the scales of the road killed individual but could observe the color and some patterns on the body. Later, on 9 December 2019, we recorded another specimen of O. cyclurus from an agricultural field in Ranjani village (26°29'15.62"N, 87°27'57.50"E), Morang, Nepal ( Fig. 1) when a woman was bitten by the same specimen while collecting grasses from the field. Upon notice, the first author approached the victim and collected the snake which was already killed by the victim believing it to be a venomous snake.
We preserved the dead specimens in 70% ethanol. The body measurements (in mm) were measured with thread and later scaled to a measuring tape; and scale counts were taken following Nguyen et al. (2020). The characters measured are: snout to vent length (SVL)-measured from the tip of the snout to the vent; tail length (TaL)measured from the vent to the tip of the tail; eye diameter (EyeL)-maximum horizontal length of the eye; interorbital distance (IOD)-the shortest distance between the eyes; internarial distance (IND)-distance between the two nostrils; supralabials (SL)-number of scales on upper lip; ventral scales (VS)-number of scales from the second ventral scale posterior to gulars to the vent excluding cloacal plate; subcaudal scales (SC)number of paired subcaudal scales excluding the terminal scute; midbody scale rows (MSR)-number of scale rows at midbody; number of preocular scales (PrO); number of postocular scales (PtO).
A Nikon-P900 digital camera with 83X optical zoom was used for the photographic record, description of colors, and patterns.

Results and Discussion
For the first (road-killed) specimen, from Pathari-Kanepokhari road segment of eastwest national highway, we could measure the total length as 690 mm. We observed the dorsal streak from the head to the tail tip. The morphological characters for the second female specimen were: smooth scales; head short and not distinct from neck; round pupils; SVL 580 mm; TaL

Habitat, natural history and threats
The genus Oligodon is a highly secretive and nocturnal snake (Tillack and Günther, 2009) and O. cyclurus is likely to have a wide distribution and tolerance of modified habitats and agricultural fields (Stuart, 2010;Das and Das, 2017). Both of our observations are from altered habitats, also corresponding to Stuart (2010). The associated habitat of the first specimen was road-side Sal (Shorea robusta) mixed forest where ground cover was mainly dominated by an invasive weed Ageratum sp. (Fig. 4A). Similarly, the second specimen was found from an agricultural habitat mosaic where wheat cropping was practiced (Fig. 4B).
Our records, both dead specimens of O. cyclurus show that the species has direct threats on its populations. Pandey (2015) mentioned the record of O. cyclurus from a snake bite treatment center by a snakebite victim and it is likely that people in the area are frequently bitten and kill the species whenever they encounter it believing it to be venomous; despite the fact that only 17 species of snakes in Nepal are venomous (Sharma et al., 2013).

Conclusion
The conservation activities of any wildlife species in Nepal are mainly targeted in Protected Areas only. Our records of O. cyclurus is ca. 50 km east of the nearest Protected Area (Koshi Tappu Wildlife Reserve) suggest that the citizen science conservation initiative (eg. distribution of photographic guides, posters or booklets of local snake fauna) provided to the farmers, school and college students with basic identification tools and ecosystem functions of snakes would be instrumental for the conservation of snakes.
O.cyclurus has been enlisted as of Least Concern (LC) in the IUCN Red list category with population trends being unknown and it is treated as a species group (David et al., 2012). Therefore, we suggest a collection-based detailed inventory of this secretive snake in Nepal to ascertain its identity based on molecular evidence. biodiversity assessment of the Pathari-Shanischare forest. We appreciate the anonymous reviewers for their valuable comments and suggestions. We also thank Netra Koirala for his field assistance and Sandhya Sharma for map preparation.