Introduction
- Project description
- Refurbishment of stately home and change of use to a 5 star spa hotel. Such refurbishment resulted in the loss of hibernation space for daubenton's and brown long-eared bats in the buildings, including cellar rooms. A new 'bat cave' was constructed as compensation.
- Ecologist’s name and contact details
- Lloyd Bore Ecology
- Planning authority
- South Bedfordshire District Council
- Brief site description
- Luton Hoo Stately Home comprises a number of buildings/structures, usually large in scale within parkland. It is situated close to agricultural land and urban fringe, with a lake complex within 1km..
Pre-works roost structure
- Type of structure
- Building
- Use
- Other
- Condition
- In Use
- Approx. age
- Original build 1774, major refurbishment in 1848
- Main construction material of walls
- Stone
- Roof design
- Pitched Roof
- Roof material
- Slate
- Internal roof structure
- Timber Frame
- Photos or annotated figures of roost structure
Pre-works roost description
- Species
- Brown long-eared bat
- Number of bats max count
- 50
- Type of roost
- Hibernation Roost
- Evidence of bats
- Bats Seen in Roost
- Roost location
- Underground Structure
- Aspect of roost
- Not Applicable
- Height of roost entrance (m)
- Ground level
- Roost material(s)
-
- Stone
- Nearest commuting feature
- Hedge
- Distance to nearest commuting feature (m)
- Not reported
Proposed works
- Description of works
- Large-scale refurbishment of stately home. This case study concentrates on the creation of the successful bat hibernation cave as compensation for loss of underground tunnels and cellar rooms. Although other bat roosts were identified elsewhere, non-hibernation roosts were either wholly avoided or mitigated by careful timing of works.
- Type of impact upon the roost
- Long-Term Roost Modification and Roost Loss
Proposed mitigations
- Type of mitigation
- Compensation
- Specific technical detail of measure
- Bat cave / hibernaculum constructed in woodland behind the main house.
Size: 15 x 1.8 x 1.8m
Materials: Brick, breeze block, concrete and earth with timber crevice additions
Additional info: The bat cave was carefully designed to provide even humidity and temperature conditions with suitable crevices for several hibernating bat species.
Estimated cost of mitigation construction (optional): £25,000+
- Relevant annotated figures
- Roost location
- Underground Structure
- Aspect of roost
- N
- Height of roost entrance (m)
- Ground level
- Roost material(s)
-
- Other
- Nearest commuting feature
- Woodland
- Distance to nearest commuting feature (m)
- Not reported
- Photos or annotated figures of roost
Actual mitigations implemented
- Type of mitigation
- Compensation
- Specific technical detail of measure
- Bat cave / hibernaculum constructed in woodland behind the main house.
Size: 15 x 1.8 x 1.8m
Materials: Brick, breeze block, concrete and earth with timber crevice additions
Additional info: The bat cave was carefully designed to provide even humidity and temperature conditions with suitable crevices for several hibernating bat species.
Estimated cost of mitigation construction (optional): £25,000+
- Relevant annotated figures
- Roost location
- Other
- Aspect of roost
- N
- Height of roost entrance (m)
- Ground level
- Roost material(s)
-
- Brickwork
- Nearest commuting feature
- Woodland
- Distance to nearest commuting feature (m)
- Not reported
- Internal temperature and humidity of roost
- 5.4
- External temperature and humidity of roost
- 4.9
- Photos or annotated figures of roost
Monitoring data
- Length of monitoring proposed
- From 18 months after construction in 2010. Monitoring ongoing.
- Frequency of monitoring
- Annual monitoring every autumn and winter by Bedfordshire Bat Group.
- Type of monitoring
- Roost Inspection
- Date and time
- 15th September 2010
- Evidence recorded
- Bats (Daubenton's Natterer's and brown long-eared) were found using the cave in the first winter of monitoring. Swarming has been observed at the mouth of cave in autumn 2010 and 2011. This is the first confirmed autumn swarming site in Bedfordshire, which considering the hibernation site has only been in place for around 4 years is an important discovery. Four male Natterer's bats were caught during swarming at the entrance in 2010 and a brown long-eared bat was caught during swarming in 2011 when other species were noted but not caught.
Bats first appeared to be using the structure within the first 12 months. First observations of bats using the site were made 18 months after completion.
- Interventions made
- None reported.
Final details
- Lessons learned
- Monitoring during the first winter after completion would have allowed us to determine which bats first used the hibernation cave. Presumably increasing the size of the cave or creating further caves would create more bat habitat but the cave and bat boxes are considered to have mitigated for the roosting areas lost.
Monitoring is essential to determine success of mitigation and should commence during the first winter from construction. Careful choice of design and materials is essential.
