Identifying the Factors That Influence Raccoon (Procyon Lotor) and Southeastern Myotis (Myotis Austroriparius) Use of Stormwater Sewer Systems

Wildlife living within human-dominated and/or modified landscapes may explore and use unconventional habitats. Our study investigates the overlooked potential of stormwater sewer systems (SSSs) as habitat for two urban-dwelling species: raccoons ( Procyon lotor ) and southeastern myotis bats ( Myotis austroriparius ). Here we focus specifically on the construction-based factors that most greatly affect the occupancy of these two species within the SSS of Alachua Co., Florida. With many vertebrates using SSSs for movement, foraging, and roosting, knowing what factors influence a system's usability is important when designing urban corridors. Our findings suggest that raccoon occupancy in SSSs was most closely related to the proximity to the nearest exit, but bats seem to select roosting sites based on a multitude of factors, including the size of the SSS, the distance to the nearest exit, and the level of impervious surface aboveground. Raccoons have a preference to remain near an exit suggesting that their presence in SSSs may be exploratory or constrained by food or light availability, although they were found navigating the full extent of some SSSs. Myotis a. prefer smaller stormwater systems with limited impervious surface disturbance aboveground, particularly in smaller SSSs. We use these findings to discuss ways that construction design and stormwater management can be more wildlife friendly.