Introduction
- Project description
- Barn conversion from agricultural to residential use. Natterer's maternity colony retained and safeguarded as part of development.
- Ecologist’s name and contact details
- BSG Ecology
- Planning authority
- Cotswold District Council
- Brief site description
- Farm building. Immediate surroundings include derelict and partially derelict farm buildings, concrete hardstanding, short horse grazed grassland and scrub with ruderal vegetation.
Pre-works roost structure
- Type of structure
- Building
- Use
- Agricultural Building
- Condition
- Not In Use
- Main construction material of walls
- Stone
- Roof design
- Pitched Roof
- Roof material
- Slate
- Internal roof structure
- Timber Frame
Pre-works roost description
- Species
- Natterer’s bat
- Number of bats max count
- 30
- Type of roost
- Maternity Roost
- Evidence of bats
- Droppings Visual
- Roost location
- Gap In Stonework
- Aspect of roost
- W
- Height of roost entrance (m)
- 4m
- Roost material(s)
-
- Stone
- Nearest commuting feature
- Hedge
- Distance to nearest commuting feature (m)
- Not reported
Proposed works
- Description of works
- The conversion works were undertaken between October and March to avoid the maternity period. The works involved modification of the existing barn to allow the existing roost to be retained and the proposed dwelling house to be built around it.
- Type of impact upon the roost
- Long-Term Roost Modification and Roost Loss
Proposed mitigations
- Type of mitigation
- Mitigation
- Specific technical detail of measure
- The works involved modification of the existing barn to allow the existing roost to remain in situ. This involved creating a dedicated bat loft in the location of the existing roost to allow the existing roost to remain and the dwelling house to be built around it. Access for bats was retained through the original open barn door entrance at the south side of the barn with an open fly-through access to the external bat loft (1.2m x 4m). A high level access (1m x 2m) from the external bat loft to the internal bat loft to the western part of the barn was created. Roosting areas including a gap in the stonework at the western gable apex and between ridge beam and ridge tiles at the western end were retained. The existing timbers of the ridge beam and rafters were retained.
After this modification during the first phase, conversion works were postponed until after the maternity period to allow the maternity roost to re-colonise.
- Roost location
- In Roof Void
- Aspect of roost
- W
- Height of roost entrance (m)
- 4m
- Roost material(s)
-
- Stone
- Nearest commuting feature
- Hedge
- Distance to nearest commuting feature (m)
- Not reported
Actual mitigations implemented
- Type of mitigation
- Mitigation
- Specific technical detail of measure
- The works involved modification of the existing barn to allow the existing roost to remain in situ. This involved creating a dedicated bat loft in the location of the existing roost to allow the existing roost to remain and the dwelling house to be built around it. Access for bats was retained through the original open barn door entrance at the south side of the barn with an open fly-through access to the external bat loft (1.2m x 4m). A high level access (1m x 2m) from the external bat loft to the internal bat loft to the western part of the barn was created. Roosting areas including a gap in the stonework at the western gable apex and between ridge beam and ridge tiles at the western end were retained. The existing timbers of the ridge beam and rafters were retained.
After this modification during the first phase, conversion works were postponed until after the maternity period to allow the maternity roost to re-colonise.
- Roost location
- In Roof Void
- Aspect of roost
- W
- Height of roost entrance (m)
- 4m
- Roost material(s)
-
- Nearest commuting feature
- Hedge
- Distance to nearest commuting feature (m)
- Not reported
Monitoring data
- Length of monitoring proposed
- 3 years
- Frequency of monitoring
- Once a year for three years during the following summers to establish whether the colony had returned.
- Type of monitoring
- Roost Inspection
- Date and time
- 1st July 2007
- Evidence recorded
- First year of monitoring, fresh droppings recorded and peak count of 30 Natterers bats during emergence surveys. Second year of monitoring, fresh droppings recorded and peak count of 35 Natterers bats during emergence surveys. Third year of monitoring, fresh droppings recorded and peak count of 73 Natterers bats during emergence surveys. This count was undertaken in July and is considered to comprise both adult and young given the large number recorded. In addition, when the site was revisited the following month the maternity roost had broken up and most bats had left the roost.
- Interventions made
- None reported
