Lesser horseshoe bat (Rhinolophus hipposideros) / Ialtóg crua-shrónach

Text & photograph © Conor Kelleher

Lesser horseshoe bat

The lesser horseshoe bat is confined to the western seaboard of Ireland. It is found in counties Mayo, Galway, Clare, Limerick, Kerry and Cork only. It is a small species and is different in many respects to the other bats on this island. It prefers areas of deciduous woodland and scrub and was once a cave dependent species. However, the species now uses farm buildings and disused cottages.

These buildings are far from ideal with low temperatures, daylight and leaking roofs. The bats are present out of desperation. Inside, the bats cluster together for warmth beneath the old earthen sod insulation or bare corrugated iron covering. The bats prefer to have a second storey to provide a range of temperatures within a building.

During the National Bat Survey, in 1994, the total Irish population of lesser horseshoe bats was estimated as 12,000 animals. This would make it the largest national population in Europe and as such it is of international importance. In Europe, the species is already extinct in the central region and there has been a recorded 87% fall in numbers in Poland alone.

This species is suffering due to its inability to adapt to modern life. Unlike the other species in the country, it is unable to land on walls or trees and cannot crawl. It needs to fly directly into the roost through a large opening and so, unlike other bats, its options are limited.

It is the most protected of all the Irish species due to its international importance. This species must, under the European Habitats Directive, where it is listed as an Annex II species, be taken into consideration during new road schemes and development.