Bailiwick bat survey gets underway
Guernsey's bat survey season is officially underway.
The project offers people in the Bailiwick the opportunity to borrow equipment to record local bats using methods devised by the British Trust for Ornithology (BTO).
The survey aims to improve understanding of the distribution and activity of the local species found in Guernsey, Herm, Alderney and Sark. It wants to raise awareness of what bats do and why it is important to conserve them.
Agriculture, Countryside and Land Management Services (ACLMS) will collect the data in Guernsey. The Alderney Wildlife Trust and La Société Serquaise will be coordinating the surveys in Alderney and Sark.
How do I take part in the survey?
Volunteers are asked to select a square (measuring 500 x 500 metres) from an online sign-up map, and to place a static bat detector in their chosen square for four nights twice per year. Once between April and mid-July and then at the same location between mid-July and the end of the October.
The bat detector automatically stores bat calls to a memory card every time a bat passes throughout a night. After four nights volunteers are asked to upload their recordings to the website and return the detector kit.
The automated sound analysis will then identify each sound recording to species. The analysis will also identify sounds made by bush crickets and small mammals.
These recordings will be manually verified at the end of the season. The survey season runs from early April until the end of October.
The booking system is now open to volunteers to choose squares to survey.
In the first year, the 2021 survey confirmed the presence of 12 bat species, five small mammal species, six species of bush-crickets, and two audible moth species.
In terms of bats, these included the first recordings of Serotine for Guernsey, Alderney and Herm, the first Leisler's Bat, Common Noctule, Lesser Horseshoe Bat and Whiskered or Brandt's Bat for Guernsey, and potentially the first records of Grey Long-eared Bat for Herm, Sark, Jethou and Lihou.