Diversity and distribution of snakes in Trashigang Territorial Forest Division, eastern Bhutan

摘要

This paper presents the results of a study conducted on the species composition of serpent fauna in Trashigang Territorial Forest Division (TTFD), Bhutan. The survey was conducted from August 2019 to September 2020. The study aimed to assess the diversity, conservation threats, and distribution of both venomous and non-venomous snakes in different habitat types using time constrained visual encounter survey technique. A total of 34 species of snakes belonging to five families and 23 genera were recorded. Of the total observed species, nine were identified as venomous species. These include four species of Elapidae, four species of Viperidae, and one Colubridae. Geographically, snakes occurred throughout the landscapes, although species composition and their geographical distribution differed notably amongst various localities . We documented survival threats to local snakes where deliberate killing and road mortality were found to be the most common cause of death. The increasing trend of diversity, species richness, and relative abundance of serpent fauna was noticed as the radial distance increased from urban residential areas towards less disturbed landscapes such as rural agricultural land and natural forests indicating that the habitat mosaic plays an important role in the structure and composition of the snake community. Considering the limited information currently available on diversity and geographical distribution of the serpent fauna of the region, the present study can be considered very significant.