The Bailiwick Bat Survey (BBS)

The Bailiwick Bat Survey (BBS) is a four-year project which uses remote automated recorders, and is the most extensive bat survey carried out by citizen scientists in the Bailiwick of Guernsey!

Bats are an important but poorly understood component of the Bailiwick of Guernsey’s fauna, despite making up more than half of the terrestrial mammal species. The BBS provides a key way of learning more about the numbers and species of bats found all across Alderney as well as the Bailiwick as a whole.

Prior to the project, eight bat species had been recorded on Alderney...this has now increased to eleven species!

The project started in 2021 and was led by The States of Guernsey’s Agriculture, Countryside and Land Management Services (ACLMS) with technical expertise from The British Trust for Ornithology (BTO) and supported by La Société and Guernsey Biological Record Centre (GBRC). The AWT is the coordinating bat centre for Alderney, aiming to survey all 48 study squares (500 x 500-m) across the island and Burhou.

The success of the BBS is down to the volunteers who sign up to survey one or more squares, often in their garden or on adjacent land. They are then provided with bat detectors to put up in their square for four nights in the first (April - mid-July) and second (mid-July - October) survey period. The acoustic data collected from the detectors is then fed into the BTO’s Acoustic Pipeline, where they are identified to species using machine learning. At the end of the year, the BTO then manually verify the records.

BBS Aims

Improve our understanding of the status, distribution and timing of occurrence of bat, bush-cricket and small mammal species that occur in the Bailiwick of Guernsey.
Involve and inspire a large section of the wider community to connect and engage with an aspect of nature that is poorly known and understood.
Help develop a community awareness of what bats do for us, what they require, why it is important to conserve them and how landowners and householders can enhance their properties for bats.

BBS Highlights for Alderney

2021
- On Alderney, 21 citizen scientists volunteered to be involved in the project
- Across the Bailiwick, a total of 720,011 sound recording files were collected
- Two new species of bat were confirmed for Alderney!
  - Serotine (Eptesicus serotinus) - this was also a new record for Guernsey and Herm!
  - Kuhl's Pipistrelle (Pipistrellus kuhlii) - records for this species were focused around Longis Road
- The Bush-cricket Large Conehead (Ruspolia nitidula) was recorded on Alderney, Guernsey and Lihou - making this the first confirmation of its presence in the Channel Islands!
- In the past, our records of the Natterer's bat (Myotis nattereri) had been sporadic, however, results from the BBS for this species were focused around the Alderney Community Woodland (ACW). This knowledge and data have helped us create new management plans for the ACW with species-specific actions.

2022
- On Alderney, 20 citizen scientists volunteered to get involved in the project
- Across the Bailiwick, a total of 3,389,138 sound recording files were collected
- Two new species of bat were confirmed for Alderney!
  - Common Noctule (Nyctalus noctula) - Alderney was the only place this species was recorded in 2022
  - Soprano Pipistrelle (Pipistrellus pygmaeus) - this species had actually been recorded on Alderney before; however, this was the first time it was confirmed through the BBS
- The Great White-toothed Shrew (Crocidura russula) was shown to be extremely widespread on the islands it was recorded in Alderney, Guernsey and Herm. Acoustic recordings were collected from gardens, farmland and semi-natural habitats.

Want to get involved and find out which creatures of the night are flying near you?

We are looking for volunteers and citizen scientists to get involved in this fantastic project for 2023 and it's easy to do! Head over to https://bats.org.gg/ and follow the quick steps to reserve your square and bat detector. Then pop into The Alderney Wildlife Trust on Victoria Street to collect the kit and you are ready to go!

If you have any questions about the BBS or need help booking your square, please contact:

Matt Lewis (Ecologist and Biodiversity Centre Manager) at ecologist@alderneywildlife.org