UES carried out a phase 1 / bat scoping survey of a private residential dwelling in October 2014. The building is located in the Oxfordshire countryside surrounded by ancient woodlands and fields, which constitutes as high quality habitat for bats.
Externally the dwelling had moderate potential for supporting roosting bats with gaps in brickwork, rot holes and gaps in the boxed soffits. These are all suitable features for crevice dwelling bats. The internal inspection of the loft provided an abundance of evidence of bat usage, including:
• High volumes of historical and recent brown long-eared (BLE) droppings
• Urine staining on the brickwork of the chimney stacks
• Carcass of a deceased BLE bat
• Female BLE bat in the loft space
All the evidence indicated that the loft space had been used as a BLE maternity roost for many years. Further presence / absence surveys were then required in order to gather additional information to support a European Protected Species Licence (EPSL) application. An EPSL was necessary due to the high potential to disturb / harm bats and a bat maternity roost during works on site. The surveys also discovered a number of common pipistrelle roosts in the building and an individual serotine bat, which is a rare species in the UK.
An outline method statement was produced by UES which formed part of the planning application for the re-development of the dwelling. The method statement included detailed mitigation and compensation measures necessary in order to safeguard protected species.
Once planning permission was granted the EPSL was applied for from Natural England in March 2015. Due to the presence of a maternity roost a purpose built bat loft was constructed on site as part of the licence. The loft was built prior to the destructive works on the existing building in order to provide immediate replacement roosting habitat. The loft was constructed with a similar size and structure of the current loft space with an uncluttered roof construction and traditional bitumen roofing felt. It was built with small access gaps at the apex and a number of access ridge and roof tiles.
Since securing the EPSL, UES have also been commissioned to act as an ecological clerk of works on site to ensure that the mitigation and compensation measures are fully implemented. This includes:
• Soft demolition of sensitive areas which included the known roosts
• Exclusion measures – one way flap / value used to allow bats to leave but prevent bat returning, in areas difficult to remove without risking injury to bats.
• Timings – works done outside of the active bat season (May to October)
• Toolbox talk to contractors by a licenced bat ecologist
• Prior inspections of the roost
On-going monitoring of the purpose built bat loft will be carried out in the active bat season 2016 and 2017 in compliance with the EPSL.