Bailiwick Bat Survey

A citizen science project to map bats across the Bailiwick of Guernsey

Are you batty about bats?

The Bailiwick Bat Survey is a citizen science project which aims to improve understanding of local bat distribution and activity.
 
The survey was commissioned as a four-year project which began in 2021 and ran until the end of 2024. We have now completed our final surveys of the project and are now in the midst of analysing the data to produce the final report.
 

We would like to thank each and every one of our volunteers who took part in the survey – whether you joined us for just one year or all four. There would have been no way we could have done it without all of your hard work. Your efforts and the survey’s results have far exceeded our expectations and the findings have revolutionised our understanding of our bat population. 

Hopefully you’ll be pleased to hear this isn’t the end… the survey will begin again in 2026, albeit just in a slightly different format. Watch this space! 

Anyone can get involved - you don't need to be a bat expert!

Survey Steps

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1

Reserve your square to survey using the online survey map.

2

Book your detector slots here – ideally book for all of your surveys. 

3

Pick up your detector on your designated day and Get Surveying! 

4

Upload the data from the detector’s memory card to the BTO app.

5

Return the detector and all other equipment to the bat centre.

6

Once your data is uploaded and processed you will be emailed your results within 24 hours! 

Step One

Book your square

Click the map to book your square(s)

We ask volunteers to select one (or more) 500x500m survey squares from the online survey map (there are 360 squares available) and to survey it twice this year – once before the 15 July and once after 15 July.

Step two

Book your detector

Bat Centres

Once you have booked a square to survey, you can book a detector from one of the Bat Centres on Guernsey, Alderney or Sark.
Click the map to book. 
 

La Société Guernesiaise, The Guille Allès Library, Fort Grey Shipwreck Museum, The Nature Commission, Alderney Wildlife Trust and La Société Sercquaise are the 2024 Bat Centres. 

The success of this project is dependent on volunteers picking up, using, and returning the detector to the bat centre as arranged. Please let us know if you are unable to carry out a survey, so there are not periods when the detector is not being used. Please also report any problems with the equipment as soon as possible.

What do you need?

  1. A smartphone (iPhone or Android) 
  2. A computer with internet 
  3. An account with the BTO to upload the recorded sound files and receive your results! 
If you do not have a smartphone or computer, please email us & we can help – you can still take part! 

When to survey?

  • You will need to carry out two surveys of your square/s – one between April and mid-July and another after mid-July until October.
  • Each survey consists of 4 consecutive nights of recordings in your square. 
You can borrow the bat detector kits with all the instructions and equipment you will need from one of our Bat Centres in Guernsey, Alderney or Sark. Twice per year, you place the detector in the square you chose from the online survey map and it will automatically record the ultrasonic calls the bats make. After 4 nights recording, you then upload the recordings to our website, return the detector kit, and our automated sound analysis will identify each call and send you the results within hours! As a bonus, the analysis will also identify sounds made by bush crickets and small mammals!

Instructions

Instructions

How to prepare for the survey, how to set up the detector and how to upload the sound recordings for analysis

Quick Start Guide

For volunteers who have previously taken part in the survey
A reminder of how to set up the detector and upload your data

Health & Safety and Risk Assessment Guidance for Volunteers

Please read through the health and safety guidance for volunteers prior to undertaking your survey.

Reports

2021 Report

Read the results from the first year of the survey

2022 Report

Read the results from the second year of the survey

2023 Report

Read the results from the third year of the survey

Inter-Island Environment Meeting 2022 Talks

'A Sound Observation: An Update on the Bailiwick Bat Survey and Opportunities of Bioacoustic Data'

Presented by Emily Coule

'Exploring the Possibilities of Acoustic Monitoring for the Channel Islands'

Presented by Stuart Newson and Phil Atkinson

Questions?

Frequently Asked Questions & Troubleshooting

If you have any queries about the project or equipment, please check out our FAQs & Troubleshooting page

Email Us

If you can't find what you are looking for, or have any further questions, please email us and we'll get back to you as soon as we can

Health & Safety and Risk Assessment Guidance for Volunteers

Please read through the health and safety guidance for volunteers prior to undertaking your survey.

Testimonials

"The Survey is an excellent example of what can be achieved - I'd like to see similar done for other species groups - we thought we had a reasonable idea of what was here, but this is eye-opening."
2021 Volunteer
Volunteer
"Engaging in citizen science projects such as the Bat Survey is an excellent opportunity for everyone, young and old, to make a difference to their local environment."
2021 Volunteer
Volunteer
"This has been very interesting. I’ve appreciated the communications from the Bailiwick bat team and I’ve enjoyed learning about the different bats and wildlife across the islands."
2021 Volunteer
Volunteer