Bat surveys

It’s a way of finding out whether bats are present on a site, then establishing details such as species, numbers and location. A survey also considers how your project might go ahead without endangering the bats.

It’s worth remembering that you won’t always be aware that you have bats. They come out at night, they hibernate, and many species roost in small spaces and crevices, so they may be difficult to see.

Like many other animals and plants, bats and their roosts are protected by UK law. This is because their populations have declined significantly and they are considered to play an important part in a healthy ecosystem, for example in pollination and insect control.

Under Regulation 43 of the Conservation of Habitats and Species Regulations 2017 (as amended) you may be committing a criminal offence if you damage or destroy a bat breeding site or resting place (whether or not bats are present at the time).

Therefore, because bats often roost in houses or other buildings, if you submit a planning application your local authority will usually ask you to carry out a bat survey as part of the process. However, even if bats are present, it won’t necessarily stop your plans. In fact, it hardly ever does. In any case, Surrey Wildlife Trust Ecology Services has the experience and expertise to guide you through the process.

By law, only trained ecologists can do this. SWT Ecology Services hold the necessary licences, at both level 1 and level 2. We can also prepare the paperwork for your bat mitigation licence, liaise with Natural England and supervise any works under the licence.

The UK has 17 breeding bat species in the UK and 18 species which inhabit our shores. 

Bats play an important role in our ecosystems, including controlling pest species and pollinating plants.  In the summer, several species of bats will eat insects including mosquitoes and midges, with even the smallest species, Common Pipistrelle eating over 3000 critters in a single night. 

Some bat species are quite common and can be seen feeding in our parks and green spaces, whilst others are very rare, including a single Greater Mouse-ear individual recorded in the UK.

Bats are protected under the Conservation of Habitats and Species Regulations (2017) and receive further protection under the Wildlife and Countryside Act 1981, as amended.  This makes it an offence to deliberately or recklessly damage or destroy any structure or place which bat(s) use for shelter or protection, disturb bat(s) while occupying a structure or place which it uses for shelter or protection or obstruct access to any structure or place which they use for shelter or protection.

Furthermore, seven bat species are Species of Principal Importance, covered under Section 41 of the NERC Act 2006.  These include Barbastelle, Bechstein’s, Noctule, Soprano Pipistrelle, Brown Long-eared, Lesser Horseshoe, and Greater Horseshoe.

(or Scoping Bat Survey)

We start by looking for signs of bats in and around the project area. This can be done by one of our professional ecologists at any time of year and includes a site survey and a desk study of local data. We will send you a copy of the report by email.

If we find no evidence of bats, you can use the report as part of your planning application. If we do find evidence, you will need to move on to stage 2.

(or Bat Emergence/Return to Roost/Dusk and Dawn Survey)

Two of our trained ecologists survey the site to identify bat species, population numbers and entry and exit points. We do this between May and September at dusk and dawn, when bats are active.

Guided by the first stage survey, we use specialist detector devices to monitor for bats leaving the roost at dusk or returning at dawn. We may have to visit more than once.

Once the survey is complete you will receive a report including next steps.

If we find evidence that bats are using your building or structure, you will need a mitigation strategy and a licence to continue with your project. This means taking specific steps to make sure the bats aren’t disturbed or harmed during the proposed work.

One of our licenced ecologists can design the mitigation strategy. Once it has been submitted and approved and planning permission has been granted, you will be granted a protected species licence by Natural England.

Before construction starts, one of our expert ecologists sets out what needs to be done at different stages to protect the bats. They work with you, your architect and your builder to enable your project to go ahead as planned, while making sure there are no breaches of conservation or wildlife legislation.

In some instances, Natural England will grant a bat mitigation licence on condition that the ecologist returns to inspect the roost over a set period. These site inspections must be on an unannounced basis.

Your bat mitigation licence will explain whether these inspections are required and over what period.