Council bats onside of mammals in bridge survey

A TEAM of bat experts has been called in by Waterford County Council to study population levels of the misunderstood mammals.

The bridges of Waterford county will be the subject of the team’s work, with more than 100 sites set to be monitored.

All bat species in Ireland are protected under European and Irish wildlife legislation and, according to Waterford County Council heritage officer Bernadette Guest, legislation and local authorities can play a part in bat conservation.

When planning new roads, new bridges or maintenance of bridges, steps can be taken to protect the existing bat population and, with this in mind, the council has commissioned the latest survey as part of the 2008 Heritage Plan programme.

“Many departments within the local authority can contribute to the conservation of bats by surveying for their presence and considering their needs as may arise through planning applications, housing inspections, demolition of buildings and infrastructural works,” said Ms Guest.

Along waterways and under bridges would be a popular habitat for bats, particularly the daubenton and pippistrelle species, and the team of experts will be aiming to gauge the levels of bat usage in local bridges.

“Stone or masonry arch bridges are particularly important for bats as their construction leaves cracks and crevices between the stones, which the bats can exploit,” said Ms Guest.

Where ongoing repair to bridges is required unsympathetic maintenance can threaten the bats using a bridge. Pointing and infilling of arches by pressure grouting can destroy bat roosts in bridges. By sealing crevices and cavities, bats are eliminated from the bridges or may become encased and cannot escape.

Ms Guest said: “Once we understand the way in which the bats use the sites, the county council can ensure that the timing of operations is sympathetic to the use of bridges by bats, for example by ensuring that no maintenance or repair work is carried out on nursery roosts during the breeding season. We can also enhance bat habitat by installing artificial roost units on masonry bridges that have been pressure grouted and any new concrete and metal bridges that are within suitable bat foraging areas.”

A previous bat survey was carried out in 1989.