Bat Surveys Made Simple – Information For Clients

Here at Acer we understand that protected species surveys and the regulations behind them, can be a little confusing for our clients. With the main bat survey season coming to a close, we thought we might provide some advice and clarification on frequently asked questions.

Why might I need a bat survey? 

The UK and Ireland is home to a total of 18 species of bats. Each of these species, and their roosts, are protected under European and UK legislation. This means that you are committing a criminal offence if you disturb a bat in its roost, obstruct access to a bat roost, or, damage or destroy a bat roost, even if it is not occupied at the time. Because of this, if a project or development is deemed likely to affect a bat population or roost, a bat survey and impact assessment will be required by your local planning authority. It is your responsibility as a planning applicant to organise and fund the survey.Bat Survey Marlborough

What is the purpose of a bat survey? 

A bat survey seeks to establish both the species and number of bats present on a development site, combined with the likely impact on any bats present during, or after, the development.

What is involved in a bat survey?

A bat survey typically involves two stages, the first is called a ‘Preliminary Roost Assessment‘. Preliminary Roost Assessments look for any sign that bats have used, or are currently using a development site. This considers the suitability of the habitat for bats and any features at the development site that could potentially provide a roosting place. Crucially, this scoping survey can be conducted at any time of year.

As part of the scoping survey, a desk study is often (but not always) undertaken. This involves a search for records of bats from a Local Records Centre. This helps to assess the potential of the site to support roosting bats, or bats using the site to forage or to commute from/to feeding grounds from their roosts.

If during the scoping survey, a development site is found to have the potential for use by roosting bats or evidence of bats is found on the site, the second stage of the survey will be required.

Bat Survey NewburyThe second stage involves ‘Activity Surveys’ which consist of dusk emergence and dawn re-entry surveys. These aim to assess how bats are using the development site, count how many bats emerge or re-enter a structure, and if so, find out which species they are. These surveys can only be carried out when bats are most active, before they hibernate for winter, typically between April and September.

An ecologist uses their professional judgement and experience to determine how many activity surveys will be required (with a maximum of three) and how often they should be spaced over the survey season. An ecologist will consider a range of evidence in making this decision, including: any evidence of bats found during the scoping survey, the quality of the surrounding habitat, records of bats and roosts in the local area, and the number and quality of potential roosting features found on site. The assessment is underpinned by bat survey guidelines published by the Bat Conservation Trust. Both the ecologist carrying out the bat surveys and the local planning authority work from the same guidelines.

What happens if bats are observed during the activity survey(s)?

After completing the activity survey, your ecologist will write a report stating how and when the survey was carried out, which bat species were observed, the impact of a prospective development on any resident bats and recommendations for mitigating this impact.

If bats are found to be present at a development site, a Mitigation Strategy will be devised. Mitigation aims to protect bats from damaging activities by reducing or removing the impact of a development. More information on bat mitigation techniques can be found here. Mitigation varies in complexity depending on the number of bats and species found on site. However, it can be something as simple as ensuring that development takes place at a specific time of year. It is important to bear in mind that the presence of bats at a development site rarely prevents development from proceeding.

Acer Ecologist Georgina Young with a Natterer's bat
Acer Ecologist Georgina Young with a Natterer’s bat

If a development cannot sufficiently minimise its impact on bats, a mitigation strategy may not be sufficient. In this instance, a European Protected Species licence will need to be obtained from Natural Resources Wales, or your local licensing body, in order for works to continue. Your ecologist will submit this licence application on your behalf after planning permission has been granted.

How can Acer Ecology assist with bat surveys?

Our fully licensed bat survey specialists are experienced in the survey, European Protected Species licensing and mitigation design and implementation.

We will assist you by undertaking scoping surveys to assess the suitability of your development site for bat habitation. We will provide expert advice on the options and solutions available to you, and should a European Protected Species licence be required, we will complete and submit your licence application.

Please contact us on 029 2065 0331 for more information on bat surveys and other ecological services.