Bats of Sark
Eight bat species were recorded on Sark between 2021 and 2024 by the Bailiwick Bat Survey, an acoustic survey run by the British Trust for Ornithology across the whole Bailiwick of Guernsey, with volunteers leaving static detectors recording through the night and La Société Sercquaise hosting the island's detectors.
Four seasons of recording produced genuinely new records. Leisler's Bat was recorded on Sark for the first time on 11 October 2023, near Derrible Head. Grey Long-eared Bats produced up to 93 recordings in a single night in La Seigneurie gardens, and their D-type social calls, the kind often associated with proximity to a roost, were recorded from only two islands in the whole Bailiwick, Guernsey and Sark.
One bat is still unidentified. A large bat was recorded eleven times at a single Sark location across three September 2023 nights. Two reviewers judged it probably a Parti-coloured Bat, a vagrant to the Channel Islands, a third thought a Serotine and a Leisler's Bat, and it stays in the record unidentified.
The detectors hear more than bats. Their by-catch gives Sark two records no other island in the survey has: the Black Rat, recorded here in all four seasons and on no other island, and the Lesser White-toothed Shrew, likewise Sark's alone.
The survey covers all the islands of the Bailiwick. Everything on this page is the Sark slice of it, and only that.
| Species | Scientific name | Seasons (of 4) | Notes |
|---|---|---|---|
| Common Pipistrelle | Pipistrellus pipistrellus | 4 | Sark's most recorded bat by far. Maximum 3,755 echolocation recordings in one night on 30 July 2022, with feeding buzzes and social calls also recorded. |
| Kuhl's Pipistrelle | Pipistrellus kuhlii | 4 | Called a common and widespread species on Sark in the final report; diagnostic social calls recorded from several Sark locations. Echolocation calls of Kuhl's and Nathusius' Pipistrelle are counted together as a species pair. |
| Nathusius' Pipistrelle | Pipistrellus nathusii | 4 | Confirmed on Sark by male advertisement social calls on 7 and 9 September 2023; September to October only across the Bailiwick, consistent with a migrant or winter visitor. Echolocation calls counted with Kuhl's as a pair. |
| Soprano Pipistrelle | Pipistrellus pygmaeus | 1 | Sark recordings only between 19 July and 1 August 2024; the report considers it unlikely to be resident on Sark. |
| Grey Long-eared Bat | Plecotus austriacus | 4 | Maximum 93 recordings in one night on 3 October 2021 from La Seigneurie gardens. Its D-type social calls, often associated with proximity to a roost, were recorded from only two islands in the Bailiwick, Guernsey and Sark. |
| Brown Long-eared Bat | Plecotus auritus | 2 | On Sark recorded in 2024 only per the species account, one recording on 19 May then 42 recordings across the island between 11 and 29 October; probably not resident on Sark. The island table shows 2 seasons, a source discrepancy kept as printed. |
| Natterer's Bat | Myotis nattereri | 4 | Detected on Sark in all four seasons per the island table; the species account narrative does not discuss Sark, a source discrepancy kept as printed. |
| Leisler's Bat | Nyctalus leisleri | 2 | New for Sark, first recorded 11 October 2023 near Derrible Head, with further recordings on 28 July and 19 October 2024. New for the whole Bailiwick during this survey; considered a rare but regular autumn migrant. |
What else the detectors heard
| Small mammals | Scientific name | Seasons (of 4) | Notes |
|---|---|---|---|
| Black Rat | Rattus rattus | 4 | Recorded on Sark in all four seasons and on no other island in the survey; Brown Rat was never recorded on Sark. |
| Lesser White-toothed Shrew | Crocidura suaveolens | 4 | Recorded only on Sark of all the islands surveyed. |
| Bush-crickets | Scientific name | Seasons (of 4) | Notes |
|---|---|---|---|
| Great Green Bush-cricket | Tettigonia viridissima | 4 | |
| Grey Bush-cricket | Platycleis albopunctata | 4 | |
| Long-winged Conehead | Conocephalus fuscus | 4 | |
| Speckled Bush-cricket | Leptophyes punctatissima | 3 | Listed for Sark for the first time in the 2023 season report. |
| Large Conehead | Ruspolia nitidula | 1 | First recorded on Sark in 2024, at Mill Lane on 15 and 16 October, having reached the Channel Islands via Guernsey, Alderney and Lihou in 2021 and Herm in 2022. |
| Audible moths | Scientific name | Seasons (of 4) | Notes |
|---|---|---|---|
| Bird Cherry Ermine | Yponomeuta evonymella | 4 | |
| Green Silver-lines | Pseudoips prasinana | 4 |
From the Bailiwick Bat Survey's annual reports and its 2021 to 2024 final report, BTO Research Report 777, by Stuart Newson and colleagues for the Bailiwick Bat Survey partnership, funded by the States of Guernsey, with Sark's detectors hosted by La Société Sercquaise. Published public reports, available at bats.org.gg.
