Droppings had been found by a rodent control officer who had investigated the building. He had determined that they were not rodent, but were most likely from a bat………..
Last week, we received an extraordinary call about bats suspected of taking up residence in an office building.
We had previously surveyed the site and had determined that the steel and glass building, still occupied by office workers, was unlikely to support roosting bats. On this basis, we had recommended that no further bat surveys would be needed. So this call was a little unexpected! Droppings had been found by a rodent control officer who had investigated the building. He had determined that they were not rodent, but were most likely from a bat.
The timing of this discovery was a particular problem. The survey season for bats (May to August) had just come to a close, and the building was scheduled to be stripped back between January and March 2013 and re-built over the course of one year. If bats were present, we were running out of time in which to carry out a valid or robust bat survey to inform a European Protected Species Mitigation (EPSM) licence to Natural England (NE), which would be required to enable works to proceed legally.
There was a real prospect that that building works would need to be delayed until surveys could be conducted in the following survey season, in May 2013 at the earliest. Deviation from the existing programme of works could have a significant impact on our clients planned move to their new headquarters.
When Dr. Yarwood-Lovett re-visted the site, she found droppings were present in small groups in three office rooms with the possibility that bats had access to the building, using gaps next to air vents to access the void between the suspended ceiling and the floor above.
Some droppings crumbled immediately to dust, a characteristic of bat droppings. The droppings were of size and shape that could be attributed to serotine bats.
However, some droppings were not crumbly and had associated moisture content not characteristic of bat droppings. Droppings were not found adhered to the wall (which is common for bats) but were only found on the ground. Given these anomalies, Sarah could not be sure these were bat droppings, so she separately packaged up the samples from each room and sent them to a lab for DNA analysis. In the meantime, she put together a plan of action in case the droppings were from bats. Structural sampling works would need to be carried out so she devised a precautionary Method Statement, including a call-out contact for a licensed bat ecologist to attend site, if this were necessary.
The results from the lab confirmed that the droppings were, in fact, pygmy shrew (an insectivore)!. This happily negated any further works and any associated delays and expenses. While this case had a happy ending, it is a good reminder that survey seasons for protected species can have an impact on work programmes and it underlines the importance of getting ecological input at the earliest stages.
Paul Southern, Assistant Chief Fire Officer for Royal Berkshire Fire and Rescue Service, commented: “As we have only very recently taken ownership of the building, it came as a surprise to learn there may have already been occupants in situ in the form of bats! If that had been the case, we would of course have done whatever was necessary to protect the bats and ensure their wellbeing.
“We are very grateful to Dr Yarwood-Lovett for her professional advice and for quickly establishing that the droppings belonged to pygmy shrews, which we understand are likely to relocate of their own accord once the building work begins.”
