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Bat Emergence Survey

If bats are on your development site, a bat emergence survey will be needed for you to apply for planning permission. Solely conducted at dusk and dawn over the summer, Arbtech provides bat surveys for developers and planners all over the UK, Get in touch for a free quote.

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Bat emergence surveys

Bat Emergence Surveys

If an initial assessment found potential roosting features, evidence of bats or high potential for bats to roost in the future, your local planning authority will need further surveys before granting planning permission. Examples of physical evidence include bat droppings, urine stains or dead bat carcasses.

Usually better known as bat emergence surveys and sometimes called bat activity surveys, bat emergence and re-entry surveys (BERS) come after a preliminary roost assessment (PRA) or scoping bat survey to confirm either the presence of bats or the likely absence of bats in the first instance via an internal and external inspection.

The assessment will provide the additional information your local council needs to grant planning consent. Without emergence/re-entry surveys to identify the habitat features that could support bats, your full planning application will likely be refused, leading to costly delays.

What is a Bat Emergence Survey?

A bat emergence survey is a monitoring exercise conducted entirely outside of daylight hours at dusk and dawn, using specialist equipment to record bat activity.

On top of being called a bat emergence and re-entry survey (BERS), bat emergence survey and bat activity survey, it is also often called a phase 2 bat survey, stage 2 bat survey, dusk and dawn survey, nocturnal bat survey and bat presence/absence survey.

With bats protected by the law, developers and planners need to arrange for an evaluation of the potential impacts on any inhabiting bats throughout the particular site.

Multiple expert ecologists will visit the development site several times to identify the species of bat, count population numbers and find the exact entry and exit points of each individual bat roost. The best time for visits to sites with a suspected bat roost is during the peak summer months.

Bat emergence surveys also allow for ecological consultants to record bat occupancy and understand how many individual bats are using the natural and man-made structures on the site as roosts.

When Would a Bat Emergence Survey Be Needed?

You need a bat emergence survey whenever new development proposals affect buildings close to natural habitats or any natural features that could be used for foraging habitat.

Using a physical inspection of the affected building or tree, an ecological consultant can determine if the specific structure has the potential to support roosting bats.

A BERS is a common factor in any planning projects involving gable ends, weather-boarding and hanging tiles (ridge tiles and roof tiles, especially on slate roofs), as all of them are perfect for crevice-dwelling species.

More often than not, local authorities will expect survey visits focusing on bats for proposed works on agricultural buildings, livestock buildings, wind farms and even a simple tree removal.

In simple terms, if there is a reasonable likelihood that a proposed development will affect bats, bat emergence surveys are a legal requirement to avoid a net loss in the natural environment. A BERS is performed to protect bats and make sure that we aren’t harming bats or their chosen resting places.

Bat Emergence Survey Guidelines

Under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017, bats are fully protected alongside other European protected species, both domestically and internationally. All types of bat surveys must be conducted by experts to ensure legal compliance.

As such, it is our duty to fulfil our legal obligation to the Conservation of Habitats and Species Regulations 2017, the Wildlife and Countryside Act 1981 and other relevant legislation and habitat regulations.

To guarantee that all results from the BERS report are accepted, all of our ecological survey work needs to follow the new bat survey guidelines from the Bat Conservation Trust (BCT).

As well as the full bat survey guidelines and sections of UK law, we also adhere to the latest standards and best practice guidelines, and any additional instructions from relevant organisations, such as the Chartered Institute of Ecology and Environmental Management (CIEEM), Natural England, Natural Resources Wales and other statutory nature conservation organisations

Bat Activity Survey Methodology

Specific conditions are important in bat activity surveys, such as ensuring that the surveys are undertaken between May and September, only conducting inspections in appropriate weather conditions to avoid heavy rain or high winds, and spacing each visit to the site by at least two weeks.

The steps below explain how a bat emergence survey is carried out:

Desk Study and Preparation

Starting with a desk-based study to gather information on bat populations and important areas for commuting bats.

Based on existing records and professional judgement, bat ecologists will be able to identify other potential roosting sites nearby.

Dusk Emergence Surveys

Arriving at the site 15 minutes before sunset and using automated static bat detectors and specialist cameras to record bats as they leave their roost.

Flight lines and flight paths will be tracked as a way of finding foraging areas.

Dawn Re-Entry Surveys

Performing re-entry surveys in certain circumstances to watch bats as they re-enter their roosts at dawn.

The two types of BERS are at dusk and dawn. A different type of survey is used to spot crevice-dwelling bats that are harder to see at night, and using different time frames will ensure that we don’t miss certain species.

Bat Emergence Survey Report

After the fieldwork, we create a comprehensive bat survey report. It is one of the most vital supporting documents for the planning process, as it contributes to planning applications and acts as evidence that an expert has conducted a detailed risk assessment.

A bat activity survey report details the roost type (e.g. day roosts, feeding roosts, maternity roosts, mating roosts, night roosts, satellite roosts or transitional roosts) and the bat species group found.

Our ecological experts also keep an eye out for other species that may be utilising the site to add extra assurances that your planning project remains fully compliant with all wildlife laws.

If bats are present, the report will provide advice on appropriate mitigation measures and mitigation requirements to avoid impacts, and it will confirm if any further action will be needed.

As soon as it’s completed, the bat report can be submitted to the local planning authorities. That said, our team ensures that it has a long shelf life to support your development from project design to completion.

Bat Emergence Survey Licence

Whenever it is likely that any bat found on your proposed site will be disturbed, you will need a European Protected Species Licence (EPSL).

A bat mitigation licence may be required if new roosts are discovered or even if only a small number of bats are found.

Bats are legally protected in both UK and European legislation, making it a crime to deliberately kill them or obstruct access to a roost. Our team can help with your low-impact bat licence application to Natural England or Natural Resources Wales.

Under a mitigation licence, an ecological consultant will be able to relocate bats, destroy roosts and create new habitats with the permission of the law.

Plan a Bat Emergence Survey Today

Our professional ecologists are able to come to your site on a suitable date, give you the necessary steps to get planning permission, and do everything possible to make project planning simple.

Whether you’re working in rural communities or an urban setting, Arbtech can help you to manage land use and prevent habitat loss by creating habitat, installing bat boxes or a vast array of other solutions.

Before you book a bat emergence and re-entry survey with our team, read more about the most suitable times for planning an assessment, the equipment we may include in the process, and the likely cost of BERS.

Bat Emergence Survey Season

The bat survey season limits when a BERS can and cannot be carried out. Each protected species is different, and due to that, assessments are arranged based on the ecology survey calendar.

Whenever bat emergence surveys are required, the aim will be to see them undertaken between May and September, as this is the optimal period outside of bat hibernation.

Alternatively, a sub-optimal time slightly outside of the summer is possible between April and October. Any other time of the year, however, wouldn’t even be considered, as enforced by Bat Surveys for Professional Ecologists Guidelines – Good Practice Guidelines from the Bat Conservation Trust (BCT).

In some specific cases involving low-potential buildings, one survey visit might be all that is needed to confirm bats, provided it takes place during this optimal window.

Phase 2 bat survey services simply aren’t possible out of season between November and March. Due to this, booking ahead is important, as it avoids waiting a longer period of time for the development work to start.

Best Equipment for Recording Bat Emergence

Bat consultants need to use acoustic monitoring, sonogram analysis, thermal technology and ultrasonic recording to complete a bat emergence survey.

For the process to be completed correctly and the results to be reliable, the following tools and equipment will be needed:

  • Analysis Software
  • Full-Spectrum Detectors
  • Handheld Bat Detectors
  • High-Powered Torches
  • Infrared Cameras
  • Night Vision Aids (NVAs)
  • Static Acoustic Recorders
  • Thermal Imaging Cameras

Bat Emergence Survey Cost

When it comes to the cost of bat emergence surveys, our administration team will create an accurate quote for you based on the dimensions of your site and the purpose of your project.

It’s possible that the phase 2 bat survey cost could be different due to the number of potential access points, the size of the building or structure, the survey effort required, and whether any other buildings or other structures are on the site. The price will also be influenced by the number of bat ecologists and visits needed to complete the assessment.

On average, dusk and dawn entry surveys consisting of two or three surveys will cost in the region of £789+VAT. To ensure that the bat emergence survey costs are accurate, we would always advise that clients get in touch with our team and request a quote straight from the source.

Local Bat Emergence and Re-Entry Survey Services

With over two decades of relevant experience, Arbtech has a large network of qualified bat surveyors all over the country. Using this structure, we can instruct a licensed ecologist to work on your behalf and carry out bat emergence surveys and other surveys you need, regardless of where your site is located.

From answering common questions about bats present on your site to the laws that make UK bat species protected in the UK, and from the use of static detectors and other tools for a more detailed assessment to submitting an application for a bat mitigation class licence to address bats and their roosts correctly, our experienced ecologists are here to help.

Our track record speaks for itself, making the validity of our results reliable in the eyes of your local council. For an excellent service and a guarantee of getting your planning application accepted, the ecologists at Arbtech can’t be beaten.

If you’re ready to start the process, you can contact us and ask for a bespoke quote over the phone, via email or by filling out a booking form on our website. We will then send you a free quote, and if you’re happy with it, return the quote form to us, and we can decide on a time for completing a bat emergence survey on your site.

Common Questions

A dusk visit starts 15 minutes before sunset and lasts for 1.5 to 2 hours; a dawn visit starts 2 hours before sunrise.
A bat activity survey is another name given to a bat emergence survey. For instance, it is similar to how a preliminary roost assessment (PRA) is also sometimes known as a bat scoping survey.
They must take place during the active season, which occurs between May and September. Outside of this period, bats are in hibernation. In rare circumstances, however, we can offer further advice if you miss this window.
In most cases, you should book as soon as your initial assessment identifies potential bat roost features. Aim for the summer to avoid unwanted delays and additional costs to your full planning application.
You must stop human activity and development works immediately. We can help with mitigation work and compensation measures to ensure you avoid disturbing bats illegally.

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