Ireland has a total of nine bat species with a possible tenth yet to be confirmed. The Park has eight of the nine species. In 2003 a new species of bat, Brandt's Bat, was found close to the Visitors Centre in Glendalough. However it is yet to be confirmed whether this specimen was a stray from the UK or Europe or whether it was derived from an Irish population of the species. The Lesser Horse Shoe Bat Rhinolophus hipposideros is the only species of bat not found in the Park. It is only found in western and south-western counties and due to declining numbers has become a species of international importance.
The commonest species of bat in the Park are the Pipistrelles, which in Latin means 'little squeaker'. There are three different species of this tiny bat, two of which are almost identical: the Common Pipistrelle and the Soprano Pipistrelle. The latter can be found roosting in the attic of the Information Office at the Upper Lake, Glendalough. Every May approximately 200 female Sopranos arrive at the Information Office to give birth to their young. They remain in the attic until September when the new-borns are able to fend for themselves. Every night just after sunset they exit the roost to feed. They can catch anything up to 3,500 insects per night before returning to the roost before sunset. The third species, the Nathusius' Pipistrelle was only recently discovered in Ireland but may have been here for some time before being found. There are few records of the species. They prefer hollow trees or crevices for summer roosts, making detection difficult.
Daubentons and Natterers
Other common bats in Glendalough are the Daubenton's Bat and Natterer's Bat. Both species like to hunt over water. Daubentons can be seen flying low over rivers and lakes, skimming the water with their tail membrane. They can even swim if they fall in. Natterers fly higher and prefer river edges. Both have white bellies and are hard to differentiate on a bat detector.
Leisler's Bats are our biggest bat species and can be seen flying high in the sky, in open areas before sunset. They are fast fliers and extremely agile in the air.
Brown Long Eared Bat
The Brown Long Eared Bat is also a common species within the Park but are very hard to detect. It has enormous ears so that it can hear insect movement in the air and especially on foliage. Consequently the Long Eared Bat doesn't rely on its sonar and so emits a very weak pulse, which can only be picked up clearly when one is within five feet of the bat. This makes detection very difficult.
Lastly the Whiskered Bat is also less common with less than 40 known roosts in Ireland. It feeds in woodlands and hedgerows near water. Its echolocation sounds very similar to Daubentons and so they may have been miss-identified. Also, it often roosts with other species which leads to it being overlooked.