As part of the Great Somerset Wildlife Count, in 2022 the bat group launched our new community bat mapping project the Big Bat Count. To help people to find out about, and count the bats in their local area.
It was a highly successful year for big bat counts.
- Around 250 people took part in 9 events across Somerset in 2023.
- 485 verifiable bat records were added to iNaturalist across 11 species
- The majority of these bat records have been validated as “Research Grade”
- However some still “need ID” and are awaiting validation
Details of the 2023 Big Bat Counts are below:
- Frome 1 – 12/5/23
- Buckland St. Mary – 19/5/24
- Castle Cary – 8/7/24
- Kingsdon – 13/8/23
- Yeovil – 19/8/23
- Frome 2 – 23/8/23
- Charlton Mackrell – 24/8/23
- Stoke St. Gregory – 2/9/23
- Brompton Ralph – 12/9/23
The results FAQ aims to answer many common questions about the processed results, including an explanation of why the numbers of “on the night” observations, and verified records, differ.
Sat 22nd April – Yeovil Big Bat Count
Thank you to the hardy 25 people who turned up at Ninesprings Park. Unfortunately, the forecast break in the rain did not happen, and so we held a Bat Talk and a short Bat(less) walk instead.
We plan to have another go at a Yeovil Big Bat Count later in the year, in August.
Fri 12th May 2023 – Frome Big Bat Count
A large group of nearly 40 people met in Frome Town Hall for a somewhat cold night of bat counting. A total of 117 bats were observed, with Soprano and Common Pipistrelle being the most common. Several Noctule were heard, along with a possible 6 other species which will need more verification.
Initial unverified observations from the night of 12th May 2023 are in iNaturalist:
- 9 Species observed during the Big Bat Count
- Bat Map produced on the night of the 117 unverifiable observations
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 37 verifiable results uploaded to iNaturalist across 3 species, Soprano and Common Pipistrelle, and Daubenton’s.
- 3 Verifiable species recorded from the Frome Big Bat Count 12th May 2023
- Bat map of the 37 verifiable bat recordings from the Frome Big Bat Count 12th May 2023
- Validated “Research Grade” bat records
Fri 19th May 2023 – Buckland St Mary Big Bat Count
A superb turnout for our first rural count of the year. Approx 25 people across 7 teams observed 148 bats across 12 auto-Ided species.
A huge thank you to all who came along, and especially to Jolyon and Jo for the hosting and warm welcome.
Common Pipistrelle and Noctule were the most frequently observed, with the first Nocule been seen 3 minutes before sunset near the church.
Serotine was also common, but there were three exciting species all with over a dozen sightings
- Leisler’s
- Barbastelle
- Nathusius Pipistrelle.
Obviously, all three will need more verification before they can be confirmed. This also applies to the other species recorded: Brown Long-Eared, Soprano Pipistrelle, Bechstein’s, Whiskered, Brandt’s & Daubenton’s.
Initial unverified observations from the night of 19th May 2023 are in iNaturalist:
- 12 Species observed during the Big Bat Count
- Bat Map produced on the night, of the 148 unverifiable observations
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 63 verifiable results uploaded to iNaturalist across 3 species, Common Pipistrelle, Serotine, Noctule, Soprano (Pygmy) Pipistrelle, Barbastelle, Daubenton’s, Brandt’s and Natterer’s.
- 8 Verifiable species recorded from the Buckland St Mary Big Bat Count 19/5/23
- Bat map of the 62 verifiable bat recordings from 19/5/23
- Validated “Research Grade” bat records
Sat 8th July 2023 – Castle Cary Big Bat Count
On Sat 8th July did our first repeat Big Bat Count in Castle Cary. Twelve people met in the Methodist rooms and set off in 5 groups to find bats.
A colder and clear night meant the bats were late to show, with Common Pip and Noctule making up the majority of the records.
Initial unverified observations from the night of 8th July 2023 are in iNaturalist:
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 50 verifiable recordings now uploaded to iNaturalist across 5 species: Common Pipistrelle, Serotine, Noctule and Soprano (Pygmy) Pipistrelle.
Weds 13th Aug 2023 – Kingsdon Big Bat Count
It was nice to see so many lovely people in Kingsdon, return for our second Big Bat Count there. Approx 35 people split up into 10 groups surveying some new as well as last years sites. Unfortunately, the rain really started to come down after 1/2 an hour, and so the total number of bats recorded was down at 73.
The most common species observed were:
- Soprano pipistrelle
- Noctule
- Common pipistrelle
- Serotine
Three observations of greater horseshoe will have further verification as these were new to last year.
Initial unverified observations from the night of 8th July 2023 are in iNaturalist:
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 39 verifiable recordings are now uploaded to iNaturalist across 6 species, Soprano (Pygmy) & Common Pipistrelle, Noctule, Serotine, Myotis (spp.) and the rare woodland Barbastelle.
Sat 19Th AUGUST 2023 – YEOVIL BIG BAT COUNT
Despite changing the date at the last moment due to the weather, there was a great turnout for the first successful Big Bat Count across Yeovil. Organised by Helen from the Wildlife Trust, around 35 people in 10 teams surveyed across Yeovil, and recorded 92 bat records.
The most frequent species was the common pipistrelle with over a third of the records. This was followed by soprano pipistrelle, serotine and noctule. Other AutoIDed records of rarer bats such as Barbastelle and Bechstein’s will undergo further analysis of the recordings.
The initial unverified observations from the night of 19th August 2023 are in iNaturalist:
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are an extra 64 verifiable recordings are now uploaded to iNaturalist across 4 species, Common Pipistrelle, Soprano (Pygmy) Pipistrelle, Serotine Bat and one species not IDed on the night, a rarer Lesser Horseshoe Bat.
Weds 23rd Aug 2023 – Frome Big Bat Count 2
Our thanks to Frome Town Council, and Jo in particular, for hosting our largest Big Bat Count to date. Over 50 people in 10 teams observed 169 bats, again a Big Bat Count nightly record.
As we found in our May count, Soprano and Common Pipistrelle were again the most commonly observed. However, this time nearly as many Noctule were seen, and there was also a good number of records of Serotine, the other larger bat.
An unrecorded fly by from a Greater Horseshoe, as well as several observations of the rarer species, will be checked when the recordings are analysed later this year.
With our sincere thanks to everyone who came out, to make it such a successful night.
Initial unverified observations from the night of 23rd August 2023 are in iNaturalist:
- 12 Species observed during the Big Bat Count
- Bat Map produced on the night of the 169 unverified observations
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 89 verifiable recordings uploaded to iNaturalist across 6 species, Soprano and Common Pipistrelle, Serotine, Noctule, Daubenton’s and 2 Lesser Horseshoe alongside the River Frome in the centre of town.
- 6 Verifiable species from the Frome Big Bat Count 23rd August 2023
- Bat map of the 89 verifiable bat recordings from Frome Big Bat Count 13/8/23
- Validated “Research Grade” bat records
Thurs 24th Aug 2023 – Charlton Mackrell Big Bat Count
Around twenty people met in Charlton Mackrell Reading Rooms, for a successful night of bat counting. The six teams observed 73 bats across 11 AutoIDed species.
With about half the records Common Pipistrelle were the most commonly recorded, with Soprano Pipistrelle next. There also were a handful of records each of Noctule and Serotine.
The other species had few sightings, and those observations AutoIDed as: Barbastelle, Natterer’s, Nathusius’s, Leisler’s and Myotis species will need further analysis over the winter.
As we are in our second year of running Big bat Counts, it is nice to see the bat maps for neighbouring villages start to join up, as in this case with Kingston and the Charltons.
The initial unverified observations from the night of 24th August 2023 are in iNaturalist:
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 41 verifiable recordings uploaded to iNaturalist across 6 species, Common Pipistrelle, Soprano (Pygmy) Pipistrelle, Serotine, Natterer’s, Noctule and the rare Barbastelle
Sat 26th Aug – Bridgwater Big Bat Count for International Bat Night
As part of International Bat Night, we had planned to run a public Big Bat Count, promoted by SWT in Bridgwater. Unfortunately the bad weather lead to a lack of bookings, and this event was cancelled.
Sat 2nd Sept 2023 – Stoke St Gregory Big Bat Count
This big bat count for Stoke St Gregory environment group was organised by Bryony from SWT, with help from Bindy from the bat group.
Bryony reported the “Big Bat Count on Saturday was a lot of fun! We had 7 groups out, ideal weather and everyone came back on a really high, having recorded bats in various locations around the parish. Bindy was absolutely fantastic sharing lots of bat-facts and sorting out the tech for us”.
The groups recorded 120 bat observations across 12 AutoIDed species. Common pipistrelle and noctule were the most frequent, both with approx a third of the sightings. Other AutoIDed records of rarer bats such as barbastelle, Brandt’s and Bechstein’s will undergo further analysis of the recordings.
Initial unverified observations from the night of 2nd Sept 2023 are in iNaturalist:
- 12 Species observed during the Big Bat Count
- Bat Map produced on the night of the 120 unverifiable observations
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 40 extra verifiable recordings now uploaded to iNaturalist across 8 species, Common Pipistrelle, Noctule, Soprano (Pygmy) Pipistrelle, Serotine, Whiskered, brown long-eared, Barbastelle & Daubenton’s
- 8 Verifiable species recorded from Stoke St. Gregory Big Bat Count 2nd Sept 2023
- Bat map of the 40 verifiable bat recordings – Stoke St. Gregory Big Bat Count 2/9/23
- Validated “Research Grade” bat records
Tues 12th Sept 2023 – Brompton Ralph Big Bat Count
Our last Big Bat Count in 2023 was for Brompton Ralph wildlife group with support from residents of Tolland. On a somewhat overcast, windy and spotting rain night, eight enthusiastic teams recorded 130 bat sightings.
With just over half the observations common pipistrelle was by far the most frequent species, soprano pipistrelle, noctule and serotine were also frequently seen.
The observations of the rarer species, including an early sighting of a greater horseshoe will be looked at more closely later in the year.
Initial unverified observations from the night of 12th Sept 2023 are in iNaturalist:
- 10 Species observed during the Big Bat Count
- Bat Map produced on the night of the 130 unverifiable observations
The bat recordings made on the night, and stored on the tablets, have been analysed, and there are 78 extra verifiable recordings now uploaded to iNaturalist across 10 species, Common Pipistrelle, Soprano (Pygmy) Pipistrelle, Serotine, Noctule, Daubenton’s, Barbastelle, Whiskered, brown long-eared, Greater Horseshoe & Natterer’s
- 10 Verifiable species recorded from Brompton Ralph Big Bat Count 12th Sept 2023
- Bat map of the 78 verifiable bat recordings – Brompton Ralph Big Bat Count 12/9/23
- Validated “Research Grade” bat records
Thanks!
The Somerset Bat Group is grateful to:
- Somerset Environmental Records Centre (SERC) for funding the ultrasonic microphones and safety equipment used in the Big Bat Counts.
- Hinkley Point C Community Fund for a grant awarded via the Somerset Community Foundation, to fund the tablets and bat call analysis software.
