New developments in snake barrier technology: fly-ash covered wall offers a feasible alternative for permanent barriers to Brown Treesnakes (Boiga irregularis)

species’ dispersal from Guam to unoccupied areas and to prevent re-colonization of areas subjected to snake control. Weinvestigated the feasibility of a fly-ash covered wall design as a Brown Treesnake barrier. We tested a mock-up of the walldesign with two surface types (rough and smooth) by providing Brown Treesnakes access to the wall as the only potentialescape route from a test chamber. All of the 100 snakes tested on the smooth finish were contained by the wall, and one outof 153 snakes tested on the rough finish was able to breach the wall. Extremely large snake size appeared to be the onlyfactor contributing to the successful scaling attempt. We conclude that this new wall design may provide a feasible and costeffectivealternative to existing wall designs, provided it meets criteria for structural integrity and longevity underenvironmental conditions present on Guam and other Pacific islands.