13 Jun Collaborative Bat Research wins two Awards from the Association of Noise Consultants
We are delighted to have had a successful evening last week in Manchester at the annual awards ceremony of the Association of Noise Consultants (ANC) winning the Innovation Award and being joint winner of the Environmental Acoustics in Infrastructure Award.
BSG Ecology has been working over the last three years with colleagues from The Ecology Consultancy, Temple Group, University of Bristol and HS2 Ltd on developing the use of acoustic deterrents as part of a bat mitigation strategy for the proposed new rail line. The research was initiated to investigate the use of high frequency noise to deter woodland bats, and in particular Bechstein’s bat, from sensitive areas of the rail corridor with the aim of keeping bats away from potential collision with trains.
Acoustic Deterrents as a Bat Mitigation Strategy
The team pooled our collective knowledge, experience and expertise to devise and implement a scientifically robust study programme to identify and quantify the impact and effectiveness of high frequency noise on bats. Noise deterrents were selected as a potential mitigation method because in recent years acoustic deterrents have been investigated to displace bats from churches and the air space around wind turbines.
Deaton Acoustic units were used to generate the noise output, and bat behaviour with and without noise was recorded using thermal imaging cameras, infra red cameras and teams of surveyors at fixed distances from the noise source. Heat sources attached to poles at different heights and distances provided markers visible to the thermal imaging cameras which enabled more accurate recording of the distances and heights at which bats were flying. A programme of survey replicated throughout the active season was implemented over two study years The first year of study demonstrated effective deterrence distances for pipistrelles, but further data for Myotis species was required to provide robust data for statistical analysis. It was also important to understand if the noise was directional and if not, what degree of noise spillage was occurring and whether this would result in unwanted displacement of bats. A second season of study and detailed analysis of acoustic data by Temple noise consultants provided greater confidence in the findings and the conclusions drawn about the effectiveness of this technique. A good understanding of the noise dispersal pattern and the effective distance enabled us to assess and adapt the sound emitted by acoustic deterrents to maximise their effectiveness in prompting localised and predictable changes in bat flight behaviour.
The study indicates that acoustics can also be used to enhance the effectiveness of mitigation measures that are proposed to be deployed along parts of HS2 Phase 1. We are also interested in the use of acoustic deterrents to divert bats from former flight paths (that have been removed) onto new flight lines linking to green bridges or underpasses.
Responses to the award
Dr Peter Shepherd, Partner at BSG Ecology said “It is a real pleasure to be working in collaboration with fellow consultants, a leading University department and acoustic experts, all committed to developing effective mitigation measures for some of our rarest bat species. The interface between practical ecological expertise, acoustic engineering design and academic discipline and expertise has been hugely enlightening and essential to making this a successful project”