Largest known greater mouse-eared bat roost found at Alqueva

The EDIA has identified what it calls Portugal's most important known roost for the greater mouse-eared bat, a vulnerable species, inside an old water mine near the Alqueva multi-purpose scheme in Alentejo. The colony, named Abrigo Beja I, holds an estimated 10,000-plus individuals and was first noticed during an inspection in April 2023, before monitoring confirmed its scale in June this year. The site also shelters three other vulnerable bat species. EDIA says the colony eats over 100kg of insects nightly, part of a wider network of 21 monitored roosts consuming over 600kg combined, aiding pest control in farmland.