Bat Conservation Global evidence for the effects of interventions 2019 Edition Anna Berthinussen, Olivia C. Richardson & John D. Altringham Synopses of Conservation Evidence Copyright © 2019 William J. Sutherland This document should be cited as: Berthinussen, A., Richardson O.C. and Altringham J.D. (2019) Bat Conservation: Global Evidence for the Effects of Interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK. Cover image: Dwarf fruit eating bat Dermanura gnoma, South America, © Adrià López-Baucells 2 Contents Advisory Board ......................................................................... 9 About the authors ................................................................... 10 Acknowledgements ................................................................ 11 About this book ...................................................................... 12 1. Threat: Residential and commercial development ........... 20 1.1. Retain existing bat roosts and access points within developments ................................. 20 1.2. Relocate access points to bat roosts within developments ............................................. 21 1.3. Install sound-proofing insulation between bat roosts and areas occupied by humans within developments ..................................................................................................................... 23 1.4. Create alternative bat roosts within developments ........................................................ 23 1.5. Change timing of building work ....................................................................................... 27 1.6. Exclude bats from roosts during building work ............................................................... 28 1.7. Educate homeowners about building and planning laws relating to bats to reduce disturbance to bat roosts ............................................................................................................... 29 1.8. Encourage homeowners to plant gardens with night-scented flowers ........................... 29 1.9. Encourage homeowners to increase semi-natural habitat within gardens ..................... 30 1.10. Protect brownfield or ex-industrial sites.......................................................................... 30 1.11. Protect greenfield sites or undeveloped land in urban areas .......................................... 31 1.12. Create or restore bat foraging habitat in urban areas ..................................................... 31 1.13. Legally protect bats during development ........................................................................ 33 2. Threat: Agriculture .......................................................... 36 All farming systems ................................................................................................................... 36 2.1. Use organic farming instead of conventional farming ..................................................... 36 2.2. Introduce agri-environment schemes .............................................................................. 40 2.3. Engage farmers and landowners to manage land for bats .............................................. 42 2.4. Provide or retain set-aside areas in farmland .................................................................. 43 2.5. Increase the proportion of semi-natural habitat in the farmed landscape ..................... 43 2.6. Reduce field size (or maintain small fields) ...................................................................... 43 2.7. Retain unmown field margins .......................................................................................... 44 2.8. Plant field margins with a diverse mix of plant species ................................................... 45 2.9. Plant new hedges ............................................................................................................. 45 2.10. Manage hedges to benefit bats ....................................................................................... 46 2.11. Manage ditches to benefit bats ....................................................................................... 47 2.12. Retain existing in-field trees ............................................................................................ 47 2.13. Plant in-field trees ............................................................................................................ 48 2.14. Create tree plantations on agricultural land to provide roosting and foraging habitat for bats 49 2.15. Retain remnant forest or woodland on agricultural land ................................................ 51 2.16. Retain or plant native trees and shrubs amongst crops (agroforestry) ........................... 54 Livestock farming ...................................................................................................................... 58 2.17. Avoid the use of antiparasitic drugs for livestock ............................................................ 58 3 2.18. Manage grazing regimes to increase invertebrate prey .................................................. 58 2.19. Replace culling with non-lethal methods of preventing vampire bats from spreading rabies to livestock .......................................................................................................................... 59 2.20. Remove livestock modifications from water troughs ...................................................... 59 Perennial, non-timber crops ...................................................................................................... 60 2.21. Prevent culling of bats around fruit orchards .................................................................. 60 2.22. Replace netting with non-lethal measures to prevent bats from accessing fruit in orchards ......................................................................................................................................... 61 2.23. Introduce certification for bat-friendly crop harvesting regimes .................................... 61 3. Threat: Energy production and mining ............................. 63 Wind turbines ............................................................................................................................ 63 3.1. Reduce turbine height...................................................................................................... 63 3.2. Reduce rotor diameter ..................................................................................................... 64 3.3. Apply textured coating to turbines .................................................................................. 64 3.4. Deter bats from turbines using radar .............................................................................. 65 3.5. Deter bats from turbines using ultrasound ...................................................................... 65 3.6. Deter bats from turbines using low-level ultraviolet light ............................................... 67 3.7. Remove turbine lighting to reduce bat and insect attraction .......................................... 67 3.8. Paint turbines to reduce insect attraction ....................................................................... 68 3.9. Close off potential access points on turbines to prevent roosting bats .......................... 68 3.10. Modify turbine placement to reduce bat fatalities .......................................................... 68 3.11. Retain a buffer between turbines and habitat features used by bats ............................. 69 3.12. Prevent turbine blades from turning at low wind speeds to reduce bat fatalities .......... 70 3.13. Increase the wind speed at which turbines become operational (‘cut-in speed’) to reduce bat fatalities ....................................................................................................................... 72 3.14. Automatically reduce turbine blade rotation when bat activity is high........................... 74 Mining ....................................................................................................................................... 75 3.15. Provide artificial subterranean bat roosts to replace roosts in reclaimed mines ............ 76 3.16. Exclude bats from roosts prior to mine reclamation ....................................................... 76 3.17. Relocate bats from reclaimed mines to alternative subterranean roost sites ................ 76 3.18. Retain access points for bats following mine closures..................................................... 77 3.19. Install and maintain gates at mine entrances to restrict public access ........................... 77 3.20. Maintain microclimate in closed/abandoned mines ....................................................... 79 3.21. Reopen entrances to closed mines and make suitable for roosting bats ........................ 80 4. Threat: Transportation and service corridors ................... 81 4.1. Install underpasses or culverts as road crossing structures for bats ............................... 81 4.2. Install overpasses as road crossing structures for bats .................................................... 84 4.3. Install bat gantries or bat bridges as road crossing structures for bats ........................... 86 4.4. Install green bridges as road crossing structures for bats ............................................... 87 4.5. Install hop-overs as road crossing structures