EXPLAINED: How to find a bat roost

Wednesday 27 July 2022

Islanders are being asked to keep an eye out for bat roosts as part of a new conservation study into where they live and breed in Jersey… But how best to find them?

RoostwatchJE is a citizen-led study being undertaken by the Biodiversity Centre and the Government’s Natural Environment team.

Islanders are being encouraged to take photos, and to log sightings or indications of roosting sites online.  

“18 different species of bat have been recorded in Jersey, but for many of these species little is known of their roosting sites,” explained Liz Walsh, Senior Environment Officer.

“Knowing where bats are resting during the day enables researchers to gather important data about the features they choose to roost in and enables the recording of bat sounds as they fly to and from their roosts. These sounds or echolocation calls are key to the development of future methods to monitor populations.

“Protecting and monitoring bats is particularly important to us at the moment as bats are facing threats including climate change, falling insect numbers, light pollution and a habitat loss. Roostwatch aims to increase our understanding of the places that bats in Jersey call ‘home’, which will enable us to do further research and help us assess their conservation status in the island.”

What to look out for...

• Gaps where bats might squeeze in (under roof tiles, behind cladding, fascia boards etc). 

• Holes in trees - for example woodpecker holes, cracks in branches or lifted bark. 

• Crumbly droppings on the ground, windowsills, and walls. If you are going into an open space like a barn or attic, keep an eye out for piles of crumbly droppings and insect wings on the floor. 

• Dark stains just below a gap where bat roosts may be present.  

• Bats leaving their roosts on warm evenings.