The Large Scaled Pit Viper Trimeresurus macrolepis is a moderately long pit viper (maximum length 580mm) with characteristic large scales on the upper surface of the head and a lower number of dorsal mid-body scale rows (12-15) than other pit vipers found in India (17-31) (Smith, 1943). The ecology and natural history of this species is relatively unknown. Arboreal and nocturnal in habit, T. macrolepis are often seen on vegetation around streams and forest trails, where they may stay without much movement for several days (Whitaker and Captain, 2004; pers.obs.). The distribution of T. macrolepis is restricted to mid and high altitude wet evergreen forests south of the Palghat Gap in the southern Western Ghats region of India.