Our client in Pwllheli asked us for a bat emergence survey in order for their project, which involved converting a chapel into a residential unit to go ahead.
Our client had already had an preliminary roost assessment carried out by Arbtech which confirmed that bats were present on the development. This type of survey is the most basic kind of survey that can be done at any time of year. If this survey confirms the presence of bats then a bat emergence survey will be required.
A bat emergence survey is a survey done at dusk and dawn between the months of May and September. Bat emergence surveys are required when there is evidence of bat activity on a property. Emergence surveys are done during these months because bats eat insects which are found less during the winter months. During warmer, drier weather, bats emerge in the evening and use echolocation to catch the insects. We complete our bat emergence surveys in accordance to industry standard guidelines (Hundt 2012).
WHAT WE DID
As with all our projects, we started off by providing a detailed quote to our client that explains everything they need to know about bat emergence surveys. We always make sure we explain things clearly with as little technical jargon as possible. Once the client had read and understood our quote, they gave us the go ahead and we scheduled in our survey.
Amy Stanley was our bat expert for this project. Amy has worked for Arbtech for many years, working as a key member of our back office administration team before moving on to become a licenced surveyor. Amy often conducts surveys all over the North West of England and many parts of Wales including Gwynedd.
Amy made a number of separate visits to the site in order to carry out the emergence survey. For this phase she was also accompanied by some colleagues who were able to watch other areas of the site where bat activity had been noted. This meant that Amy had to make fewer individual visits to the site and the survey could be done quicker.
During the survey, Amy made use of a wide range of tools during a detailed inspection of both internal and external areas of the property including a torch, ladders, binoculars and sample bags. Amy also made use of a broadband bat detector. This is a device that allows us to hear a bats echolocation call that is usually inaudible to the human ear.
Whilst conducting a bat emergence survey, Amy had these objectives:
- To determine the intensity of bat activity
- To determine the type of bat activity – for example foraging, commuting or mating
- To find roosts by tracking bat flight paths
- To find or record the emergence of bats from a building or built structure
After a thorough investigation, Amy was able to provide more detail on the type of bat activity on the site. Amy and the other surveyors made notes about the species of bats found on the site and the kind of activity that was taking place. Amy collected all the relevant information to and produced a detailed report for the client explaining all the findings clearly.
The key findings of the survey were that bat roosts on the development were confirmed and that the development would affect the bats roost. We made a number of recommendations that would allow the development to go ahead without having a negative impact on the bats. These measures included:
- Removing slate tiles by hand under ecological supervision
- Installing replacement roosting in the new building via bat access tiles or bat tubes
- Installing bat boxes on suitable building and trees that are part of the development
The client was able to use our report to help prepare an application for a European Protected Species licence and they were very happy with the speed and efficiency of our service from start to finish.