Bat Surveys

Need a Bat Survey?
Wildwood are one of the UK’s most experienced bat specialists

Why is a bat survey needed?

Numbers of bats in the UK have declined considerably over the years and now all species of bats found in the UK and Ireland and their resting places (roosts) are protected by law. Therefore, where a project or development is considered likely to affect bats or their roosts, a survey and assessment of impacts will be required.

The survey will need to establish the species and number of bats likely to be affected together with an assessment of the likely impacts on bats arising from the development proposal.

A survey is needed if your local planning authority, or your architect, planning agent or ecologist consider that there is a reasonable likelihood of bats being present and affected by the development proposal.

In coming to their conclusion, they may have considered factors such as the nature and scale of the development, the suitability of existing structures (e.g. the age and style of the building), and the suitability of the surrounding landscape for bats and/or whether there are existing records of bats using the area.

Who carries out and is responsible for a survey?

It is the responsibility of the client to organise and pay for the survey. If the applicant has an agent, they may be able to arrange for the survey to be undertaken on their behalf. The survey itself will be carried out by one of our ecologists who is experienced in carrying out surveys and assessment for bats and a licence holder. We may need to approach a local records centre on your behalf to obtain records of bats in the area. You will be expected to pay for the costs charged by the record centre for this, if required to do so.

Preliminary Roost Assessment

Our involvement typically starts with a Preliminary Roost Assessment (PRA). The objective of this daytime assessment (or bat scoping survey) is to establish likely absence or the presence of bats from either buildings, trees and structures. It’s coordinated by a licensed bat ecologist using specialist equipment and in accordance with the latest published guidance. All structures, other than those with negligible suitability, may require additional bat emergence surveys. This service can be carried out at any time of the year.

Bat emergence surveys

A bat emergence survey (or phase/stage 2 survey) are dusk or dawn surveys where surveyors observe the exit or entry of bats using specialist equipment, including bat detectors, thermal imaging or infra-red cameras and data loggers.

Surveys are restricted to the months between May and September (download our free survey calendar). The objective is to confirm the number and species of bat using a feature and how they use it, so proportionate mitigation or compensation measures can be implemented under a mitigation licence.

What happens when the survey is completed?

Following the survey, we will need to write a report setting out how and when the survey was carried out, what we found, the impact of the development on bats and our recommendations based on your project or development and the reasonably likely impacts on bats. If it is concluded that bats are present a ‘Mitigation Strategy’ will need to be developed, which may require development taking place at certain times of the year, the use of certain materials and/or specific provision to allow bats to continue to use the original or replacement roost.

Bat Survey Frequently Asked Questions

Are bats protected by law?
Yes – there are 18 species of bats which are protected by legislation in the UK.

This means it is a criminal offence to carry out the following:
1. Take, injure or kill a wild bat.
2. Intentionally or recklessly disturb a bat in its roost or deliberately disturb a group of bats.
3. Damage or destroy a bat roost (a place used by bats for breeding or resting), even if bats are not present at the time.
4. Possess or advertise/sell/exchange a bat of a species found in the wild in the EU (dead or alive) or any part of a bat.
5. Intentionally or recklessly obstruct access to a bat roost.
You can learn more about domestic and international laws protecting bats by reading the Wildlife and Countryside Act 1981 .
When can a bat survey be done?

For a simple daytime inspection, such as a Preliminary Roost Assessment (PRA), this can be arranged at anytime of the year. Following our visit we can advise you if any further surveys are necessary, such as activity surveys or bat emergence surveys. Where these additional surveys are necessary to fully establish the presence or absence of bats, then typically we would arrange for these to be undertaken between May and August. Occasionally there is scope for surveys to start earlier in the year, but usually only by a few weeks as the daytime temperatures can fluctuate widely in early Spring. Similarly, we can also survey well into September, but not where larger roosts may be present, such as a maternity roost, as the majority of bats could have already dispersed.
Do I need to have a bat survey for re-roofing or maintenance works?

The short answer – it depends! If you have been advised to carry out a bat survey before you start works, or suspect you may have bats, then your first action should be to contact us. We can discuss the nature of your works and then advise if we think that your proposed works could impact on bats or a bat roost. For smaller or low-impact projects a bat survey may not be required. For full re-roofing or major restoration works, then a preliminary roost assessment is highly likely.
Can I assume we have bats and erect some bat boxes?

However sensible this may seem, bat boxes are only suitable for a small number of bat species or roost types. Although some bat species readily make use of bat boxes, such as pipistrelle bats, others have very specific roost requirements. The lesser horseshoe bat for instance needs a larger space within a building/structure to fly around in and a dedicated ‘open’ access point and never uses a typical bat box. Also, larger groups of bats, such as those found in a maternity roost, require larger spaces to raise their young. If your project will impact bats or a bat roost then you may need a bat mitigation licence, and the issuing authority needs confirmation of species, numbers and how they use the site. All of which would need to be identified as part of a bat survey.
How much does a bat survey cost?

It depends on where you are based in the UK, the size and complexity of your site/project and the number or type of surveys required. It could be that all you require is a daytime Preliminary Roost Assessment and report, which confirms that no bats or roosts are present. For other sites, you may have to have a number of emergence surveys (typically between 1-3 additional site visits) with a number of bat surveyors present to watch all elevations for bats emerging or returning – the larger the site, the more surveyors will be needed and hence cost! For sites confirmed as a bat roost, once planning permission has been granted or other consents obtained, then we will then apply for a bat mitigation licence on your behalf. So, it really does vary. Contact us for advice and for a quotation.
How far do Wildwood ecologists travel for a bat survey?

Here at Wildwood, we are always conscious of our carbon footprint and try to minimise travel where possible. As a general rule, our ecologists will travel within 1.5 hours of either the Stroud or Caerphilly office. If your project is further than this, we do suggest you seek an alternative consultancy.

You can try CIEEM’s Registered Practices Directory, or we are always happy to make our own recommendations, which in turn will be more cost effective for you.