Bat Emergence and Re-Entry Survey (BERS)
A proposed development can affect bats by harming bats themselves and damaging the roosts present on the site. It is common for this to happen during building, extension or demolition work, with both UK and European legislation ensuring that bats are legally protected through the Conservation of Habitats and Species Regulations 2017 and the Wildlife and Countryside Act 1981.
Whenever development sites could potentially have bats present, the developer would need a bat survey to determine the presence of bats or the likely absence of bats. A preliminary roost assessment (PRA) is stage 1 in the process and sees a licensed ecologist conducting a desk study and survey visit to work out the site’s potential for species of bat between low suitability, moderate suitability and high suitability.
If it turns out that bats are present – or even if the ecological consultant simply can’t rule out occupancy due to evidence of bats, such as feeding remains, foraging areas and suitable resting areas – a bat emergence survey will be needed. It is known as stage 2 in the bat survey process, and a full planning application will only be viable once both assessments have been completed.
What is a Bat Emergence Survey?
Often called any number of different things – including a bat emergence and re-entry survey (BERS), bat activity survey, dusk and dawn bat survey, and dawn and dusk emergence survey – bat emergence surveys are a secondary type of survey effort that involves two or more surveyors and takes place at least 15 minutes before sunset and at least 1 hour and 30 minutes after sunset.
More specifically, professional ecologists will monitor entry and exit points based on important areas defined during the initial assessment. Using automated static bat detectors and other specialist equipment, commuting bats going in and out of access points will be recorded. Based on that data, information can be collected on bat populations and bat species.
A dawn and dusk bat survey is required anytime a PRA cannot rule out the presence of bats and their roosts. It could even be that the expert ecologists discover roosting features that suggest high potential to support roosting bats, such as hanging tiles, ridge tiles, roof tiles, weather-boarding or other structures on the affected building or on other buildings close to the site.
Bat Emergence Survey Methodology
Over several visits to the site, multiple experienced ecologists will take necessary steps to keep tabs on the known entry and exit points for individual bats on the site. If there was a bat roost or a bat found during the earlier internal and external inspection, a more detailed assessment can take place in the expected resting places of crevice-dwelling bats.
Alternatively, the need for further action will be due to the potential for bats on the site or certain circumstances that make efforts to avoid disturbing bats especially important, such as the nature of the new development, the instructions of the local council, a past discovery of other natural habitats, or the potential impacts on present bats protected by relevant legislation.
The three main factors that need to be investigated during the bat activity survey protocol are the certain species of bat, the predicted population numbers, and the likely purpose of the site from the perspective of the bats. With this information, the consultants managing the process can create appropriate mitigation and compensation measures to support bats during and after the proposed works.
Bat Emergence Survey Report
Within the bat activity survey report that follows the physical inspection, all of the information needed by the local planning authority will be contained. For instance, it will explain the bat activity survey methodology, summarise the proposed works, detail any overlap between the planning process and priority species of bats, and confirm the mitigation requirements and any need for a bat mitigation class licence.
If any further surveys are needed based on findings on the site, habitats regulations or bat survey guidelines, the ecological consultant will make that clear in the report. More than anything, bat emergence survey reports are created to give the local authorities assurances that the correct surveys are undertaken beforehand and to map out the chosen mitigation measures. With everything ticked off, the developer should see no problem in getting planning consent.
Bat Emergence Survey Guidelines
If you need bat activity surveys on your site or even just want dawn and dusk bat survey advice, our team are experts and have conducted numerous bat emergence surveys all over the country for countless clients.
Not only that, but by choosing us, you get a level of bat activity survey validity in everything we do, as we remain focused on your legal requirement to native bats. We also frequently refer back to the good practice guidelines of the Chartered Institute of Ecology and Environmental Management (CIEEM), Natural England / Natural Resources Wales and the Bat Conservation Trust (BCT).
Our expertise includes experience with DNA testing, night vision equipment, European protected species licence applications, installation of bat boxes, working with rural communities and local planning authorities, and stepping in on big and small developments, from homeowner extensions to the development of wind farms.
More information on our dawn and dusk bat surveys – including cost, timing and quotes – can be found in the section below.
Bat Emergence Survey Cost
It is likely that all bat surveys will fluctuate in price due to the size of the development site and the scale of the planning project. In the case of bat emergence survey costs, the final price will be based on the number of ecologists and visits to the site needed to complete the assessment.
For an accurate quote based on your project and site, as well as the level of bat activity survey you would need, speak to our team, and we will be able to produce an estimated price for conducting dusk and dawn bat surveys on your site.
Bat Emergence Survey Times
It is crucial that developers understand the bat emergence survey calendar and schedule a set of BERS within the annual bat emergence survey window.
Instead of just one survey, a bat activity survey involves three surveys or possibly more, depending on the findings from each visit. It’s also important to note that a gap of at least two weeks will be needed between each visit as a way of representing the site more accurately. Not only that, but in the case of poor weather conditions such as heavy rain or high winds, the results will not be reliable, and visits will need to be rescheduled.
Getting the bat activity survey timing right is an unavoidable part of booking a BERS, and it is dictated by the bat survey season.
Bat Emergence Survey Season
All bat activity surveys must be carried out within the bat activity survey season. The optimal time is seen as the best time of the year, seeing the visits undertaken between May and September. Otherwise, the suboptimal time is between April and October, and it is strictly out of season between the months of November and March.
Developers are advised to get surveys undertaken as early as possible, booking ahead of time and aiming for the summer months, ideally between May and August.
Ask for a Quote Now
It could be that you need help with getting a bat licence, checks for new roosts, analysis of the type of roost on your site, assurances that development proposals won’t harm fully protected bats, or booking in a bat emergence survey following an earlier preliminary roost assessment.
Even if we didn’t have anything to do with the early PRA or any preliminary ecological appraisal or ecological impact assessment before that, we will happily step in to help with providing environmental management and proposing mitigation work for your planning project.
On a set date, one of our team can visit your site to undertake a bat emergence survey and use existing information about the expected roost type, the state of the natural environment, and any reasonable likelihood that would see the development obstruct access to roosts. From there, we can then help with mitigation licence applications and anything else standing in the way of getting planning permission.
Get a free quote from our team for bat activity surveys today by calling us, emailing us or filling out a quote form on our contact page.