Earlier this summer, our team carried out a licensed hand-netting bat survey on a site in the South East of England and made a significant discovery: a grey long-eared bat (Plecotus austriacus), one of the UK’s rarest and most conservation-sensitive bat species.
A Rare Bat Survey
Hand-netting was carried out under the appropriate licence as part of a wider suite of surveys aiming to assess bat use on the site, which includes a mixture of high-quality foraging habitats,
Phlorum staff examining the wing of a grey long-eared bat
farm buildings and mature trees offering potential roosting opportunities.
During one of the dusk sessions, a long-eared bat was safely caught in-hand. Given the challenge of visually distinguishing between grey and brown long-eared bats (Plecotus auritus), careful measurements were taken, including forearm length, tragus width, thumb length, and fur colouration, all subtle but essential indicators.
Initial measurements and physical features strongly suggested a grey long-eared bat, but due to the close similarity between the two species, further analysis was required to confirm the identification.
Confirmation by eDNA
To back up our field identification, we collected faecal samples from the bat for DNA analysis. This non-invasive method allows for highly accurate species-level identification, using genetic markers found in the bat’s droppings.
The results confirmed what we suspected: the captured individual was indeed a grey long-eared bat, a species with a highly restricted distribution in the UK, mostly limited to southern coastal areas.
Conservation Implications
The confirmation of Plecotus austriacus at this site adds valuable data to the national understanding of this elusive species’ distribution. Grey long-eared bats are a Priority Species under the UK Post-2010 Biodiversity Framework and are considered one of the most range-restricted mammals in Britain, with fewer than 1,000 individuals thought to remain.
Their presence highlights the importance of preserving high-quality foraging habitats, such as unimproved grasslands, and ensuring roosting sites including barns, old buildings, and mature trees are retained or suitably protected during any development or land management planning.
A Responsible Approach
All work was carried out under a Natural England licence, with bat handling conducted by trained and appropriately licensed ecologists. The bat was released safely at the point of capture shortly after data collection, minimising stress and following strict animal welfare protocols.
Looking Forward
This encounter was not only scientifically valuable, but also a reminder of why we do what we do. Discoveries like this underscore the importance of robust survey methodologies, collaboration with genetic labs, and ongoing professional development in bat survey techniques.
We’re proud to contribute to the growing knowledge base on this rare species, and we’ll continue working with conservation bodies and local authorities to ensure their habitats are protected and understood.
Want to learn more about grey long-eared bats or discuss bat survey requirements for your site? Get in touch with our team — we’re always happy to talk bats.
Richard Schofield is an environmental manager with wide knowledge and experience in managing environmental issues on sites. He is responsible for managing Japanese knotweed and Ecology projects across the UK for Phlorum.
