Measurement of Fog Oil Penetration into Model Underground Burrow and Hollow Tree Nest Cavities

摘要

The Gopher tortoise (Gopherus polyhemus) and the Indiana Bat (Myotis sodalist) are species found on many military installations. The Indiana bat is endangered throughout its range, and the Gopher tortoise is threatened in its westernmost distributions and at risk everywhere else. On installations where troop readiness training is conducted, an important component of realistic troop readiness training is the generation of obscurant material and the conduct of maneuvers under obscurant cover. Fog oil (FO) has long been deployed for visual obscuration training, and the effects of such obscurants on these species are unknown. As a preliminary step prior to instituting toxicological studies, a laboratory simulation was performed on the capability of FO to penetrate the living space of these species: the tortoise burrow and the hollow- tree location of a bat maternity colony. The FO smoke did not enter the simulated tortoise burrow in significant concentrations, but the smoke concentrations in the simulated tree cavity approached ambient levels under some test conditions. This suggests that tortoise burrows do not need to be studied in-situ, and that the tortoise may be considered protected while in the burrow. Bat maternal colony sites, however, should not be considered protected from smoke entry to any significant degree.