Barbastelle Volunteer Bat Survey
A new project, in collaboration with the University of Sussex, is starting in May 2021. We aim to test a new approach to survey woodlands for the presence of barbastelle bat colonies, using acoustic detectors. Discovering where barbastelle colonies are is the first step in understanding their conservation needs.
Barbastelles are a woodland specialist species and one of Britain’s rarest mammals. They are officially classed as vulnerable to extinction in Britain and are considered ‘Near Threatened’ globally by the International Union for the Conservation of Nature (IUCN). However, little is known about the species. Colonies can be found distributed sparsely across the south of Britain, yet a broader understanding of their habitat requirements at a landscape-scale have yet to be thoroughly explored.
Our PhD student Kieran O’Malley has developed a protocol for the acoustic monitoring of woodlands for the presence of barbastelle colonies. By working alongside both bat groups and volunteers, we will now be implementing this protocol to survey woodlands on a large scale.
In this project, volunteers will help collect baseline information on barbastelle colony distribution using acoustic methods. We hope that the work will identify new woodlands where barbastelles are present, and also help us to understand why some woodlands are used by the species, whereas others are not.
Frequently Asked Questions
1 Where and when are the surveys taking place?
This year we are focusing on West Sussex; Herefordshire; Wiltshire; Buckinghamshire, Northamptonshire, and Bedfordshire. Please see the maps below for further details. In future years, we hope to extend the survey area further. The survey season this year runs from mid-May until the end of August.
2 Do I need experience?
Anyone, irrespective of experience, can get involved.
3 What does it involve?
A Barbastelle Survey Base will be set up in each of our study areas, from which you can borrow equipment. You will need to put the acoustic detectors in one of the designated survey woodlands and collect the equipment again a few days later. Further information is available in the survey methods below.
4 Do I have to get landowner permission?
This has already been done. All you need to do is to go for a walk in the wood and put out the bat detectors!
5 Will I find out whether the wood has barbastelles?
We will send you a bat activity report, which will include a detailed breakdown of barbastelle activity and colony likelihood.
6 How do I sign up?
If you would like to get involved, please register as a Vincent Wildlife Trust Volunteer. Please return your registration form to email@example.com, referencing the project and region (eg, Wiltshire) which you wish to help survey.
Reserving your woodland and detectors
This map will be updated throughout the season with new woodland sites. Please note, that it is essential that you use the sign-up form so that we know that the woodland has been allocated to you. Once your woodland has been selected, the form will take you through the steps to book and borrow detectors from your local Barbastelle Survey Base.
Pre-defined booking slots will allow for three nights of recording, with detectors being returned ideally on day four (ie, the day that the detectors are retrieved from the woodland). If this is not possible, they should be returned on day five. Please note that a booking slot may extend past five days if the Survey Base is closed.
Barbastelle Survey Bases
Each of the study areas (West Sussex, Wiltshire, Herefordshire, South Midlands) will have a dedicated Barbastelle Survey Base. After you have booked your detectors, you will need to collect your detectors from your local base. The online form will give you more information on the best point of contact, opening hours, and whether you need to contact the base in advance.
To ensure that all planned woodlands are surveyed, it is important that you pick up, use, and then return the detectors to your local Barbastelle Survey Base as arranged. If you are unable to carry out the survey, or cannot return the detectors as arranged, please contact us as soon as possible to ensure there are no periods when the detector is not being used. Please also report any problem with equipment as soon as possible.
For your survey, we are encouraging you to work alongside a survey partner. This will allow you to share the load of carrying bat detectors and means someone is available to help in case of an accident. It is also more fun! If you already have a survey partner, you are only required to submit one online sign-up form, but please add details of your survey partner(s) when requested.
If you do not have a survey partner but would like one, then an option is available on the form that will open up your survey for other volunteers to join. However, if you need to carry out the survey alone, please ensure that you have a nominated ‘buddy’ that you check-in with when you set off and return. You will need to tell this person exactly where you are going and what time you expect to come back so that they can raise the alarm if needed.
For some very large woodlands, having a survey partner may be a requirement in order to safely carry the large amounts of equipment needed. This will be made clear on the form.
Where and when to survey
Detector locations – The number of detectors required for your survey will be specified beforehand and will vary depending on the size of the woodland. Larger woodlands will require more detectors, and therefore it is recommended that you work in a small group to complete these surveys. You must provide your own appropriately sized bag to transport and carry detectors, so please take this into consideration when selecting your woodland.
To determine the best locations to deploy your detectors, please download the free mobile app ViewRanger, which lets you view OSM maps. This app will allow you to easily identify where detectors should be placed when out on your survey. When initially opening the app, you may be prompted to download Outdooractive. Please select the option ‘Continue with ViewRanger’.
After you submit your survey request, you will be emailed a GPX file to download onto your phone. This will contain suggested detector locations for your survey. A video tutorial on how to import and view this data in ViewRanger can be found below. Alternatively, if you are unable to download and use ViewRanger, please let us know on the signup form and we can provide GPS coordinates and map images to you.
Recording form – A simple recording form will be provided when you borrow equipment from the base. It is extremely important that the recording form is completed and returned to the Barbastelle Survey Base when equipment is returned. The recording form will ask you to record the dates that the detectors were deployed and the GPS coordinates of exactly where each of the detectors was left.
If you have a GPS, you can use this to determine the coordinates of each location where a detector was left out. Alternatively, please use the ViewRanger app to determine GPS coordinates. You can change the ViewRanger coordinates format in the settings (see video). Please provide coordinates in a latitude/longitude format with decimal degrees (eg, 50.961379, -0.849339 or N50.961379, W0.849339).
Weather – Please do not carry out surveys if it is forecasted for persistent heavy rain, strong wind or if the temperature is predicted to fall well below 10oC at sunset. You can check the weather by using the BBC weather website. Please ask us if you are unsure whether you should carry out your survey.
Detector and microphone placement – The correct placement of microphones is critical to ensure high-quality bat sequences are produced. Ideally, placement should follow these criteria:
Please watch the following video to learn more about the detectors you will be using and how to correctly deploy them:
Photo: Barbastelle ©Frank Greenaway