Bridging the Gap Between Bats and Transportation Projects

1. Bridging the Gap BetweenBats and Transportation Projects An Overview of Bats, Bridges, and Mitigation Opportunities Robin Perez and Edward Samanns Dale W. Sparks, David Tull, Ted Cable, and Robert Tunison Louis Berger Group Environmental Solutions & Innovations, Inc. National Cooperative Highway Research Program (NCHRP) Project 25-25, Task 102, Artificial Bat Roost Mitigation Designs and Standardized Monitoring Criteria

2. Acknowledgements: • This study was conducted for the AASHTO Committee on Environment and Sustainability, with funding provided through the National Cooperative Highway Research Program (NCHRP) Project 25-25, Task 102, Artificial Bat Roost Mitigation Designs and Standardized Monitoring Criteria. The NCHRP is supported by annual voluntary contributions from the state Departments of Transportation. Project 25-25 is intended to fund quick response studies on behalf of the Committee on Environment and Sustainability. The report was prepared by Dale W. Sparks, David Tull, Ted Cable, and Robert Tunison of Environmental Solutions & Innovations, Inc., and Robin Perez and Edward Samanns of Louis Berger Group. The work was guided by a technical working group that included: • Timothy Hill, Ohio Department of Transportation • Amy Bailey, California Department of Transportation • Kris J. Gade, Arizona Department of Transportation • Christine (Chris) Maguire, Oregon Department of Transportation • Jeff S. Peterson Colorado Department of Transportation • Mary Kay Solberg, Iowa Department of Transportation • Kevin Moody, FHWA (Liaison) • The project was managed by Ann Hartell NCHRP Senior Program Officer. • Disclaimer:  • The opinions and conclusions expressed or implied are those of the research agency that performed the research and are not necessarily those of the Transportation Research Board or its sponsoring agencies. This report has not been reviewed or accepted by the Transportation Research Board Executive Committee or the Governing Board of the National Research Council.

3. Frequent Regulatory Issue for DOTs • Rapid Population Declines • Long-term Habitat Declines and Concerns • White-Nose Syndrome (WNS) • Mortality at Wind Energy Sites • Many Species Are Already Protected • Federal Endangered Species Act • 7 Species listed as endangered • 1 Species listed as threatened • 17 Species tracked as species of concern • State Rare Species Laws • Low Reproductive Potential = Slow Recoveries Tricolored bat with WNS. Why Bats? Red bat found under a wind turbine.

4. A Three-Step Program For Compliance • Inspection: Recognize Bat Habitat • Avoidance and Minimization of Negative Impacts • Mitigation for Unavoidable Impacts Bear in Mind These Flow Into Each Other

5. Like All Wildlife, Bats Need: • Food • In North America. this is usually insects • Sometime pollen and nectar • Rarely blood (vampire bats occur in northern Mexico) • Water: • Drink on the wing • Usually pools or calm portions of streams • Shelter: Called Roosts • A Landscape that Connects These Features Inspection: Recognizing Bat Habitat This stream provides bats with food (aquatic insects), water, and shelter (trees).

6. Examples of Natural Roosts Inspection: Recognizing Bat Habitat Caves are especially important in winter. Trees provide bark and cavities. Some bats live in rocky habitat.

7. Examples of Anthropogenic (Man-made) Roosts This mine is gated to protect bats from human disturbances during hibernation. Inspection: Recognizing Bat Habitat Big brown bats roosting in a bridge. Bat boxes are designed to attract bats. Bats were caught as they left this house.

8. Finding Out if Bats are Present • Conduct Surveys • Place mist nets in appropriate habitat which may vary by season and location Inspection: Recognizing Bat Habitat

9. Finding Out if Bats are Present • Conduct Surveys • Use harp traps across mine/cave entrances Inspection: Recognizing Bat Habitat . Trapping a Batbox Trapping a Mine

10. Finding Out if Bats are Present • Conduct Surveys • Acoustic bat detectors Inspection: Recognizing Bat Habitat Microphone Stand Bat Detector

11. Finding Out if Bats are Present • Conduct Surveys • Emergence counts Inspection: Recognizing Bat Habitat Preparing for an Emergence Count

12. Finding Out if Bats are Present • Conduct Surveys • Check potential roosts Inspection: Recognizing Bat Habitat Biologists inspect a bridge Bats beneath a bridge Bat guano under a bridge Surveyors look, listen, and smell for bats or their sign

13. Avoiding and Minimizing Impacts to Habitat • Treat Bat Habitat Like You Do Wetlands • Avoid key features like known roosts • Impact at right angles • Impact areas of lower quality • Use Seasonal Avoidance • Like birds, most bats migrate • Impacts at the time the bats are absent avoid a direct impact to bats • Avoid mid-summer when baby bats are present • Exclude bats from roosts Avoiding and Minimizing: Limit Negative Impacts Biologists used expanding foam and bird netting to exclude bats from this bridge during repairs—thus avoiding direct mortality.

14. Avoiding and Minimizing: Limit Negative Impacts New Highway . Future Mitigation Minimal Forest Lost Forest Avoided Multiple approaches used in combination

15. Remember Bats Need: • Food, Which is Rarely Limiting • In the range of long-tongued bats, use bat foods for revegetation. • Aquatic habitats can be important food sources for insectivorous bats. • Water, Which is Limiting in Some Areas • Rarely limiting in the eastern U.S. • Ponds in the western U.S. and in the highlands of Appalachia can be important. • Shelter/Roosts, Which are Often Limiting • Breaks down regionally • East: Typically an issue with forest • West: Loss of bridges can be a key issue • We Tend to Overlook the Importance of a Connected Landscape Mitigation: For Unavoidable Impacts Ponds provide food and aquatic insects

16. Bat-friendly Bridges can Provide Roosting Habitat for Bats • Many types of Bridges are Used, but • Most Bats are Found in Four Types of Structures Mitigation: For Unavoidable Impacts Summary data from 39 publications that contain data on 3,964 bridges and culverts reviewed during the study.

17. Bats Prefer Large, Concrete, or Concrete and Steel Bridges Likely Due to Thermal Properties Mitigation: For Unavoidable Impacts Summary data from 39 publications that contain data on 3,964 bridges and culverts reviewed during the study.

18. Bats Prefer Bridges Surrounded by Appropriate Habitat • Bats Prefer Bridges Over Water Mitigation: For Unavoidable Impacts Data courtesy of Chris Smith, Minnesota DOT

19. Artificial Roosts Can be Added to Bridges to Provide or Improve Roosting Habitat Mitigation: For Unavoidable Impacts Texas bat abode fits between concrete I-beams. These structures can provide roosts for open-space or crevice-roosting bats. A three-sided box fits against a crossbeam. These structures can provide roosts for open-space or crevice-roosting bats. The Oregon wedge connects to the crossbeam. These structures can provide roosts for crevice-roosting bats.

20. Examples of stand-alone Artificial Roosts • Aimed at Crevice or Cavity-Roosting Bats • Most have slots that are ½ to 1&½ inch wide • There is a trade-off between cost and thermal stability • Internal temperatures should be 80° and 100° Fahrenheit • Temperatures above 113° Fahrenheit are lethal Mitigation: For Unavoidable Impacts

21. A Wide Variety of Stand-alone Artificial Roosts can be Used to Provide or Improve Roosting Habitat Mitigation: For Unavoidable Impacts Indiana bat under bark Rocket Box Rocket boxes provide habitat for many bat species

22. Examples of artificial roosts that simulate loose bark • Mostly aimed at Indiana bats • Likely area of future development • Internal temperatures should be 80° and 100° Fahrenheit • Temperatures above 113° Fahrenheit are lethal Mitigation: For Unavoidable Impacts Cedar Shake: Unsuccessful Tarpaper Skirt: Unsuccessful Shake Garland: Limited Success Bat Bark™: Limited Success BrandenBark:™ Successful NOTE: Proprietary products included for completeness and not intended as an endorsement.

23. Where to Locate Mitigation • Onsite • Places mitigation at/near the site of impact • Can reduce costs by avoiding the need to purchase additional lands • Can require a long-term commitment • Successful mitigation may affect future projects Mitigation: For Unavoidable Impacts Pond used as mitigation Artificial Roost used as mitigation

24. Where to Locate Mitigation • Off-site • Places mitigation outside the project footprint • Requires access to additional land • Can require a long-term commitment • Successful mitigation can be used to lure bats away from the location of on-going work Mitigation: For Unavoidable Impacts . Cave gate used as mitigation

25. Financial Approaches to Mitigation • Residual Properties • Places mitigation on unused lands purchased for the project or owned by the agency • Can greatly decrease the cost of mitigation if the land is not slated for another use • Fee-Simple Purchase • Project proponent purchases a site expressively for mitigation • Long-term management can lead to unforeseen expenses • Often donated to a conservation organization for management • In Lieu Fee • Applicant pays a fee for impacts • A third party uses that money to implement off-site mitigation • Often very popular at first due to their simplicity • Can create a market for high-value mitigation properties • Many agencies move away from this system once properties have been purchased that have a high conservation value and low market value—initial successes can lead to long-term insolvency. • Mitigation Banking • An entity (third party, department, etc.) creates mitigation in advance • Applicant purchases credits as they need them • Over time, this approach can convert a series of incremental impacts into contiguous areas of high quality habitat Mitigation:

26. Ways to Complete Mitigation • Habitat Preservation • Habitat Enhancement • Habitat Creation • Can be combined as was the case at the Indianapolis Airport Mitigation: For Unavoidable Impacts Area impacted by development (white triangle) Habitat preservation, planting, and enhancement (yellow polygons)

27. Ways to Complete Mitigation • Habitat Preservation • Protects high-quality habitat in the short-term • Results in a long-term loss of habitat • Example: Purchase a known hibernaculum or woodland that contains bat roosts Mitigation: For Unavoidable Impacts This cave now harbors thousands of Indiana bats

28. Ways to Complete Mitigation • Habitat Enhancement • Improves habitat quality in the short-term • Results in a long-term loss of habitat (in terms of acres, but not necessarily in quality) • Often used as a bridge strategy so young habitat can mature • Examples: install bat gates or bat boxes Mitigation: For Unavoidable Impacts This artificial roost provides habitat in a young forest

29. Ways to Complete Mitigation • Habitat Creation • Provides long-term replacement for habitat lost due to construction • Often requires time for the habitat to mature—resulting in a short-term loss of quality • Examples: create underground habitat, create ponds, or plant new forests Mitigation: For Unavoidable Impacts Before and after images of a pond that created new bat habitat.

30. Points of Contact Contacts Regarding Questions Dr. Dale W. Sparks, ESI dsparks@envsi.com Additional Contacts Mr. Edward Samanns, Louis Berger ed.samanns@wsp.com Dr. Ann Hartell, NCHRP ahartell@NAS.edu Final Report and BMP Manual Available At: https://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=4098