Thermal fumigation provides a simple and effective solution for sanitizing cargo from invasive snakes

摘要

The Brown Treesnake (Boiga irregularis) is invasive in Guam and threatens to be dispersed by military and civilian transportation activities to other islands in the Pacific, where it could be expected to inflict similar damages. Prevention of inadvertent export of snakes in cargo and vehicles currently relies on trained canine detection teams, which are expensive to use and unable to detect all snakes. Hence, there has long been interest in developing effective and cheaper means of fumigating cargo to remove snakes. A companion study has shown that chemical fumigation is unlikely to be readily developed into a practical tool. Here, we demonstrate that these snakes are readily induced to quit test refugia by application of streams of heated air. Many parameters affect snake response times, but we find that application of relatively low temperatures (48–52˚C) at moderate delivery rates (3.4 m3/min) is sufficient to induce exit of these snakes within 5 min. Development of a portable heat-delivery system based on these findings has great potential to ensure snakes do not unintentionally stow away to other locations in cargo, munitions, vehicles, or airplane wheelwells. Application of such technology can be done on Guam as well as at locations receiving cargo or vehicles from that source, providing an additional layer of security in ensuring these snakes do not colonize additional locations outside their native range.