The lesser horseshoe bat is a very special bat species found mainly in Mayo, Galway, Clare, Limerick, Kerry and Cork. This species has declined and even gone extinct in some parts of continental Europe, therefore, it is a very highly protected bat species. It is listed on Annex II of the European Habitats Directive.

Its population is doing reasonably well in the west of Ireland at present. Since monitoring began in the mid-1980s the population has increased by over 60%. This may be the result of a combination of better protection at roosts, and/or increased cover of its favourite habitat for foraging – broadleaved woodland, climate change may also have played a role.

Nonetheless, this species is very vulnerable to disturbance and habitat loss. There is particular concern about the state of disrepair of many of the derelict buildings that form the species’ roost network.

Monitoring of this species is carried out in winter and summer, mainly by staff of the NPWS as well as the Vincent Wildlife Trust. Count data is then collected and analysed by Bat Conservation Ireland.