An Inspection for Signs of Bats and an Evaluation of Bat Roost Potential of the Disused

An inspection for signs of bats and an evaluation of bat roost potential of the disused buildings of the Former Golf & Tennis Centre, The Regent’s Park, 26 August 2010

by

Dr Nigel Reeve (Head of Ecology) The Royal Parks

1. Introduction.
   This is an account of an inspection carried out of the disused buildings of the Former Golf & Tennis Centre which are planned to be demolished/removed from site. This inspection was carried out to determine whether the buildings show any signs of being used as bat roosts and the bat roost potential of the buildings.
   
2. The buildings consist of one single-storey shed-like timber building in a poor state of repair, and an adjacent large single-storey ‘Portacabin’ with two entrances in a good state of repair. Both buildings were sealed with screwed-on plywood sheets covering any entrances, so all inspection was external.
   
3. The buildings were inspected from 10:30am-11:45am on 26 August 2010 by Nigel Reeve, assisted by Tony Duckett (Senior Wildlife Officer, The Regent’s Park). Weather conditions at the time were good but with light rain. Some heavy rain overnight and during over the last few days could potentially have washed away bat droppings on the ground around the buildings had they been present.

1. Survey Method.
   The buildings were visually inspected with the aid of a high powered torch (1million candlepower) and a fibre optic endoscope to investigate holes and cavities that could be potential roost sites. A ladder was available for use but was not needed. Any potential features that could possibly have been used by bats were inspected for signs of bat use, i.e. stains from greasy fur, urine stains or droppings. Any surfaces and cobwebs were searched for bat droppings; especially under or within features that could potentially be used as a roost. Photographs of all features that could provide potential roost sites were taken.

1. Results - the timber ‘shed’ building.
   Refer to the photographs. Figure 1 shows the overall ‘shed’ with its door and other access points covered with stout plywood panels. The eaves were in good condition with tight joints and no obvious access points for bats. The plywood panels were screwed on and usually tight against the structure, sometimes sealed with mastic. However, a few features that could potentially be used by bats were evident:

3.1.Where the boards were not tightly screwed enough or had lifted slightly for example as shown in Figure 2. Potentially bats could wedge themselves behind boards where there was a gap of at least 10mm. All these features were carefully inspected and no evidence of bat occupation was found. Many were covered by cobwebs indicating a lack of use.

3.2.The south wall of the ‘shed’ was covered in roofing felt which, in a few places was lifted to create small pockets where individual bats could potentially shelter (Figure 2). No evidence of use by bats was found.

3.3.A small opening above the screwed on panel on the low structure (north east facing side) shown in Figure 3. This showed no signs of use and was completely covered in cobwebs.

3.4.Two areas with rotten and missing panels allowing potential access to the cavity of the wall (e.g. Figure 4) were found . Some mineral wool insulation was present, but this was sparse. The endoscope was used to check within the cavity as far as practical. The horizontal batons and spider webs within the cavity were checked for droppings. No signs of bat occupation were found. Only a couple of mouse droppings were found in one cavity and some nesting material was present in the other.
Figure 1. The ‘shed’

1. Results. The Portacabin.
   This building has extremely low bat potential. The eaves were tightly sealed and the whole building was rendered in mastic-like substance (Figure 5). Only one feature that could have given bats a potential roosting site was:
   
2. A misplaced cover over a downpipe on the southern side of building the making access to the eaves a possibility (Figure 6). No signs at all of access or occupancy (checked with endoscope) were apparent although the gap was not covered in cobwebs.

1. Conclusions.
   
2. The ‘shed’.
   No signs of bat occupancy were found, but the building does have some (low) bat roost potential. Although there is a low probability of bats being present, the following precautions are recommended.
   
3. Demolition should (as a precaution) proceed in stages starting with the plywood panels which should be systematically removed and checked for bats as they are removed.
4. Similarly, care should be taken when prying away timber cladding and insulation, especially when close to potential entrance areas (the areas with missing cladding). Workers should be on the lookout for bats.
5. Work should take place in fine weather conditions as soon as possible before hibernation begins, ideally before mid-October and certainly before November. This means that any individual bats that could be using the building will be able to fly away if disturbed.
   
6. The Portacabin.
   
7. This building has negligible bat roost potential.
8. It is nevertheless impossible to completely rule out the potential future presence of one or more bats therefore (as above) work should take place as soon as possible and care should always be taken when dismantling any building.
9. In this case particular attention to the small possibility that one or more bats could be present in the southern end eaves should be paid when dismantling the southern wall with the displaced drainpipe.

1. Additional recommendations.
   
2. If a bat is discovered at any time during the works, it must not be handled and work must cease. The following actions should be taken immediately:
   a) A licensed bat worker should be contacted (via the London Bat Group). This is so even if an active uninjured bat flies away. The worker will advise over the phone and consider the likelihood of other bats being present. S/he will also consider any legal requirements.

b) A full record of events should be kept, including contacts and times of telephone calls, or other communications.

6.2.Both buildings are raised from the ground with sizeable gaps under them that could possibly be used by other animals, such as foxes and hedgehogs (known to be present in The Regent’s Park),wood mice, frogs, toads and so on. If work is carried out, as recommended above, before November there will be no possibility of disturbing breeding females with young. Similarly hedgehogs will not yet be hibernating (unless the weather becomes very cold). Any small animals found in nests, or simply present under the buildings can be gently moved to the cover of the adjacent hedgerow.

NJR 26/08/2010

Page 1