The Normandy caves
Although only 100 miles from Calais, Normandy has 18 species of bats, many of which are not found (or are rare) in south-east England. Perhaps the most spectacular of these is the mouse-eared bat, which has a widespread distribution throughout the region and is commonly found hibernating in caves or underground sites. Twenty-one maternity colonies totalling 1,900 females are known of; the largest of these has up to 400 bats.
Each winter, between 800 and 1,200 greater horseshoe bats are counted at hibernation sites – the second most frequently found species at that time of year. By contrast, very few maternity colonies have been found, although one that is still occupied by 20 bats was first recorded in 1828!
The lesser horseshoe bat is rare in Normandy, except in the Pays d’Auge, an area of limestone hills and river valleys similar to the Cotswolds. Although it may be overlooked, this species is seldom recorded in summer.
Geoffroy’s bat is unknown in the UK. It is fairly common in Normandy and favours similar conditions for hibernation and breeding as the greater horseshoe bat. Seven maternity colonies have been found, the largest of which contains up to 350 females.
The whiskered bat is common throughout Normandy and is the species most often encountered in underground sites during the winter.