Cooperative Fish and Wildlife Research Units Program: Virginia
Education, Research and Technical Assistance for Managing Our Natural Resources

Of all Federal ownerships, Department of Defense land managers are faced with the most unique stewardship challenges of balancing training and mission needs with National Environmental Policy Act and Endangered Species Act compliance. Significant portions of the agency’s ownership contain habitats with numerous threatened, endangered, and at-risk species. For installations in the Northeast and mid-Atlantic such as Fort Drum, New York, bats constitute a faunal group of high conservation concern to installation managers. Formal consultation with the U.S. Fish and Wildlife Service and the necessity of expensive mist-netting surveys is an annual reality for project clearance; many natural resource management activities, such as forest management and range maintenance, often are modified or seasonally restricted to account for these species’ ecological needs and to avoid Section 7 “take”. However as bat populations decline from the impacts of White-nose Syndrome, mist-netting survey methods increasingly fail to provide data for regulatory clearance due to low catch-per-unit-effort (also higher “per bat” costs), yet population declines and additional listings will require increased monitoring efforts . To meet this critical need and to potentially significantly reduce monitoring costs by eliminating the need for inefficient mist-netting, use of acoustical sampling (frequency division Anabat SD2) of bat echolocation could serve as an alternative, less costly method with greater detection power. Development and validation of detector placement design and analytical strategies to characterize temporal variation in bat activity, e.g., day, month, season (emphasis on maternity roost areas) and movement route/timing for both short- and long-distance migrants also are needed. OBJECTIVES: 1) Demonstrate the potential for multiple acoustical device placements (15-25 units) and multiple continuous sampling (3-10 nights per site per unit) to assess bat species assemblages, occupancy modeling, and detection probabilities for monitoring and regulatory clearance; 2) demonstrate the potential value of these data to assess relative bat activity at landscape- and stand-level scales (upland and riparian habitat associations and spatial and temporal patterns of movement, i.e., along known and presumed corridors and between day-roost areas/woodlots); 4) ascertain potential sampling and test analytical protocols for effective use of multiple detectors deployed over long duration efforts. 4) compare cost and logistical considerations of acoustical methods in comparison to contractor-supported mist-netting generally and in the context of declining catch and cost efficiencies following WNS.