Characteristics of a Snake Community in the Hilly Forest of Quan Son District, Northern Vietnam

The snake communities in Asian tropical forests are relatively unknown, with most studies focusing on species lists. We investigated species composition, relative abundance, and community ecology of snakes in a mature secondary hilly forest area in the Quan Son District, northern Vietnam. To our knowledge, it is one of the few field investigations focused on snake community structure to have been undertaken within the Indo-Burma Hotspot, which is one of the most biologically important regions on the planet. We surveyed snakes along random transects in forests during two time periods (10–12 d), between 500 and 1,350 m elevation. In 361.8 h of surveys, we encountered 19 species, with a clear altitudinal separation in snake assemblages and numbers. Encounter frequencies dropped with elevation but had a peak at the intermediate elevation of 600–699 m. We therefore observed a Mid Domain Effect in our snake community in terms of both species richness and number of individuals observed. Of the 19 recorded species (including one Pythonidae, 11 Colubridae, two Elapidae, one Pseudaspididae, three Viperidae, and one Xenodermidae), 78.9% were exclusively or primarily terrestrial, 42.1% were semiarboreal, and 21% were semiaquatic (with some species belonging to two guild categories). We also present new natural history observations of snakes in the region. We discuss the importance of our findings relative to other similar studies conducted in South America and Africa, in addition to those in Vietnam and South-East Asia.