Spatial ecology of a small arboreal ambush predator, Trimeresurus macrops Kramer, 1977, in Northeast Thailand

Abstract

Abstract The Big-Eyed Green Pit Viper (Trimeresurus macrops; Kramer, 1977) is a venomous snake species endemic to Southeast Asia. Although we have some knowledge of the systematics and toxicology of T. macrops, little is known about the spatial ecology of this species. From May 2013 to February 2014, we used radio-telemetry to determine home-range sizes of 13 adult female T. macrops inhabiting the Sakaerat Biosphere Reserve in Northeast Thailand. We found that individual home ranges for T. macrops averaged 0.175 ha, with activity areas ranging from 0.112-0.303 ha and core areas ranging from 0.023-0.052 ha. There was little overlap between conspecific tracked females, especially for the most used areas of their home ranges. We find that T. macrops ambushes more in higher humidity and expresses very little diurnal activity. They use the groundstory for ambushing, then retreat over small distances to higher refuge during the day. Future studies should focus on prey abundance, habitat selection, and survival rates.