Bat Surveys: Buildings and Trees

All bats and their roosts are protected by law. Bats use a variety of man-made and natural structures for their roosts, including buildings, bridges, tunnels, and trees. If a development is proposed that could affect these structures then they must be assessed to determine whether or not bats are present and if they could be affected by the development. Bat surveys need to be undertaken by experienced and licenced professionals and involve a two-stage process.

The first step is to carry out a Roost Assessment to determine the likelihood of bats being present in a structure. This involves a thorough external inspection to record features such as missing roof tiles or tree cavities that offer potential access points for bats. Internal inspection of roof voids, tree cavities etc. may be necessary to search for bats or signs of their presence, such as droppings. This can be done by one of our licenced ecologists at any time of the year, although potential hibernation sites should be inspected November to March.

If evidence of bats is found, or potential roost features recorded, then further surveys are required to determine the bat species and the type of roost present. Depending on the suitability of the potential roost feature, a number of dusk and dawn surveys must be completed to monitor bats emerging from and entering in to a structure. We use a range of technologies and techniques to help with our surveys, including thermal imagining, ultrasonic bat detectors, video endoscopes and rope access.

The results of these surveys inform whether or not a licence and mitigation strategy are needed to legally facilitate the development, which our expert, licenced ecologists specialise in developing with our clients.