Bat Conservation Global evidence for the effects of interventions 2021 Edition Anna Berthinussen, Olivia C. Richardson & John D. Altringham Conservation Evidence Series Synopses 2 © 2021 William J. Sutherland This document should be cited as: Berthinussen, A., Richardson O.C. and Altringham J.D. (2021) Bat Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK. Cover image: Leucistic lesser horseshoe bat Rhinolophus hipposideros hibernating in a former water mill, Wales, UK. Credit: Thomas Kitching Digital material and resources associated with this synopsis are available at https://www.conservationevidence.com/ 3 Contents Advisory Board.................................................................................... 11 About the authors ............................................................................... 12 Acknowledgements ............................................................................. 13 1. About this book ........................................................... 14 1.1 The Conservation Evidence project ................................................................................. 14 1.2 The purpose of Conservation Evidence synopses ............................................................ 14 1.3 Who this synopsis is for ................................................................................................... 15 1.4 Background ...................................................................................................................... 15 1.5 Scope of the review ......................................................................................................... 17 1.6 Methods ........................................................................................................................... 18 1.7 How to use the information provided ............................................................................. 34 1.8 How you can help to change conservation practice ........................................................ 35 1.9 References ....................................................................................................................... 35 2. Threat: Residential and commercial development ........ 37 2.1. Retain existing bat roosts and access points within developments ................................. 37 2.2. Relocate access points to bat roosts within developments ............................................. 39 2.3. Install sound-proofing insulation between bat roosts and areas occupied by humans within developments ....................................................................................................... 40 2.4. Create alternative bat roosts within developments ........................................................ 41 2.5. Change timing of building work ....................................................................................... 45 2.6. Exclude bats from roosts during building work ............................................................... 46 2.7. Educate homeowners about building and planning laws relating to bats to reduce disturbance to bat roosts ................................................................................................. 47 2.8. Plant gardens with night-scented flowers ....................................................................... 47 2.9. Increase semi-natural habitat within gardens ................................................................. 48 2.10. Protect brownfield or ex-industrial sites.......................................................................... 48 2.11. Protect greenfield sites or undeveloped land in urban areas .......................................... 49 2.12. Create or restore bat foraging habitat in urban areas ..................................................... 49 2.13. Legally protect bats during development ........................................................................ 51 3. Threat: Agriculture ....................................................... 54 All farming systems .............................................................................................................. 54 3.1. Use organic farming instead of conventional farming ..................................................... 54 3.2. Pay farmers to cover the costs of conservation measures (e.g. agri-environment schemes) .......................................................................................................................... 60 3.3. Engage farmers and landowners to manage land for bats .............................................. 62 3.4. Provide or retain set-aside areas in farmland .................................................................. 63 3.5. Increase the proportion of semi-natural habitat in the farmed landscape ..................... 63 3.6. Reduce field size (or maintain small fields) ...................................................................... 64 3.7. Retain unmown field margins .......................................................................................... 64 3.8. Plant field margins with a diverse mix of plant species ................................................... 65 3.9. Plant new hedges ............................................................................................................. 66 4 3.10. Manage hedges to benefit bats ....................................................................................... 67 3.11. Manage ditches to benefit bats ....................................................................................... 69 3.12. Retain existing in-field trees ............................................................................................ 69 3.13. Plant in-field trees ............................................................................................................ 70 3.14. Create tree plantations on agricultural land .................................................................... 70 3.15. Retain remnant forest or woodland on agricultural land ................................................ 72 3.16. Retain riparian buffers on agricultural land ..................................................................... 73 3.17. Retain or plant native trees and shrubs amongst crops (agroforestry) ........................... 74 Livestock farming ................................................................................................................. 79 3.18. Avoid the use of antiparasitic drugs for livestock ............................................................ 79 3.19. Manage grazing regimes to increase invertebrate prey .................................................. 79 3.20. Replace culling of bats with non-lethal methods of preventing vampire bats from spreading rabies to livestock ............................................................................................ 80 3.21. Manage livestock water troughs as a drinking resource for bats .................................... 81 Perennial, non-timber crops ................................................................................................. 82 3.22. Prevent culling of bats around fruit orchards .................................................................. 82 3.23. Use non-lethal measures to prevent bats from accessing fruit in orchards to reduce human-wildlife conflict .................................................................................................... 83 3.24. Restore and manage abandoned orchards for bats......................................................... 84 3.25. Introduce certification for bat-friendly crop harvesting regimes .................................... 85 4. Threat: Energy production and mining .......................... 86 Wind turbines ....................................................................................................................... 86 4.1. Apply textured coating to turbines .................................................................................. 87 4.2. Deter bats from turbines using radar .............................................................................. 88 4.3. Deter bats from turbines using ultrasound ...................................................................... 88 4.4. Deter bats from turbines using low-level ultraviolet light ............................................... 91 4.5. Remove turbine lighting to reduce bat and insect attraction .......................................... 91 4.6. Paint turbines to reduce insect attraction ....................................................................... 92 4.7. Close off potential access points on turbines to prevent roosting bats .......................... 92 4.8. Modify turbine placement to reduce bat fatalities .......................................................... 93 4.9. Retain a buffer between turbines and habitat features used by bats ............................. 93 4.10. Prevent turbine blades from turning at low wind speeds (‘feathering’) ......................... 94 4.11. Slow rotation of turbine blades at low wind speeds ........................................................ 98 4.12. Increase the wind speed at which turbines become operational (‘cut-in speed’) ........... 99 4.13. Automatically reduce turbine blade rotation when bat activity is high......................... 105 Mining ...............................................................................................................................