Towerhill Cottage is a single storey former dwelling located north of Ballinrobe, County Mayo. The lesser horseshoe bats use the attic spaces of the cottage in summer but hibernate close by in two other structures, both ruined manor houses; an underground passage associated with Towerhill House and in the cellars of Moorehall House. Both ruins are surrounded by woodland, primarily conifer, which is managed by Coillte Teoranta, the semi-state forestry body. Hence, the bats have adequate vegetation within which to safely fly between their summer and winter sites, and as feeding grounds. The cottage was purchased by the Trust in 1999 and since then the number of bats using it has increased from 200 to 471 in 2021.
Although many of the Trust’s Irish reserves were located as a result of extensive summer surveys of ruined buildings, the discovery of a colony at Towerhill Cottage was a result of research conducted towards the end of the hibernation period in 1997. In March that year the Trust obtained a licence from the NPWS to attach rings, similar to those used on birds for identification purposes, to the forearms of a small number of horseshoe bats in underground sites, one of which was the underground passage at Towerhill House. The silver rings are clearly visible in torch light when the bats are viewed within a roost. The aim of this research was to establish links between known winter roosts and existing and potential summer roosts, and to learn about the distances travelled by the bats. A link between the underground passage and the cottage was confirmed during summer 1997 when ringed bats were spotted in the attic of the latter.
