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  • NABat Coordination Team

The AFWA Bat Working Group Passed Its First Resolution

The Association of Fish and Wildlife Agencies Bat Working Group (AFWABWG) recently passed a resolution that supports a more consistent effort in transportation structure surveys for bats. The resolution encourages state natural resource agencies to collaborate with state Departments of Transportation and asks them to consider the presence of bats at all bridge and culvert projects. It also encourages the use of the standardized national Bats and Transportation Structures (BATS) survey protocols and the submission of recorded data to the North American Bat Monitoring Program’s (NABat) database when feasible. This resolution promotes the effective management and conservation of bat populations while continuing to address transportation infrastructure improvement needs without project delays.

The final resolution and supporting materials can be reviewed by clicking here and on the AFWA Bat Working Group Website under Resources. The AFWA Bat Working Group is in the process of finalizing a guidance document and survey data templates with the help of NABat. The U.S. Fish and Wildlife Service is also working on transportation structure survey guidance with an anticipated release in spring 2024.

Bats use a variety of habitat types for roosting, foraging, hibernating, and rearing young such as caves and trees. Increasingly, they also use man-made structures such as mines, tunnels, bridges, culverts, barns, and attics as the loss of natural habitat make bats more reliant on them.

Species that have been documented using transportation structures include: 

  • Antrozous pallidus

  • Corynorhinus rafinesquii

  • Corynorhinus townsendii

  • Eptesicus fuscus

  • Eumops floridanus

  • Lasionycteris noctivagans

  • Lasiurus cinereus

  • Macrotus californicus

  • Myotis austroriparius

  • Myotis californicus

  • Myotis cililabrum

  • Myotis evotus

  • Myotis grisescens

  • Myotis leibii

  • Myotis lucifugus

  • Myotis occultus

  • Myotis septentrionalis

  • Myotis sodalis

  • Myotis thysanodes

  • Myotis velifer

  • Myotis volans

  • Myotis yumanensis

  • Nyticeius humeralis

  • Parastrellus hesperus

  • Perymotis subflavus

  • Tadarida brasiliensis



Detweiler, L. W., & Bernard, R. F. (2023). Wildlife Use of Anthropogenic Structures: A Comprehensive Review of Bridge Use by Bats. Acta Chiropterologica25(1), 135-157.


Johnston, David & Briones, Kim. (2019). Final Caltrans Bat Mitigation: A Guide to Developing Feasible and Effective Solutions. 10.13140/RG.2.2.23252.53121.


Wetzel, T., & Roby, P. (2023). Bats Use of Bridges and Culverts (No. cmr 23-008). Missouri. Department of Transportation. Construction and Materials Division.


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