357 North Main Street
Memphis, TN 38103

by Ben Day
Senior environmental specialist

On April 2, 2015, the U.S. Fish and Wildlife Service issued their final rule listing the northern long-eared bat as a threatened species under the federal Endangered Species Act. The NLEB joins the Indiana bat as the two typical endangered bat species that have a potential presence in West Tennessee and the surrounding areas of Arkansas and Mississippi. Populations of these species have declined dramatically since the discovery of white-nose syndrome (a fatal fungus) in bats in New York in 2006. As a result of white-nose syndrome, populations of the northern long-eared bat have declined by 99 percent.

Because these species are listed under the federal ESA, they must be addressed in projects utilizing federal funding or otherwise requiring federal authorization, such as wetlands projects requiring U.S. Army Corps of Engineers permitting. West Tennessee does not provide significant winter hibernation habitat due to the topography and geology of the area; however, the bats are known to migrate into the area and utilize the local ecology for summer breeding and foraging. To evaluate the potential presence of these species, the USFWS publishes guidelines for their survey within project areas. The typical first phase of these surveys in West Tennessee is to conduct a Summer Habitat Assessment to identify potential roost areas (e.g. snag (dead) trees with appropriate size, bark types, and cavities; bridges; etc.) within the project area that additionally meet suitability criteria such as maintaining sunlight exposure and proximity to foraging areas (particularly wooded riparian zones).

Projects can typically be modified to avoid impact by either redesigning or by performing construction activities in the winter months to avoid “take,” the physical interaction with a species. If unavoidable impact to summer habitat is required, a Presence/Absence Survey, through ultrasonic acoustic studies, mist-net studies or other approved methodology, may be implemented to demonstrate that no individuals are currently present in the area. Additionally, assuming the project can demonstrate sufficient efforts to avoid and minimize impact, any necessary habitat removal can typically be mitigated without significant cost or project modification. Projects with unavoidable take may be subject to significant modifications. They may even be denied funding or permitting or may require significant mitigation including relocation efforts.  

Tioga’s natural resource scientists routinely conduct the habitat assessments necessary to receive Section 7 clearance for projects in West Tennessee. We look forward to working with our clients to plan, design and permit their upcoming environmental projects.