Bat Surveys

If you are carrying out building or development work that may disturb a bat roost you will be asked by your local authority to undertake a bat survey to support your planning application. Although you may think that bats are not present you will still need an experienced and qualified ecologist to determine this for you.

Bats and their roosting and resting sites are fully protected under UK and European law. It is offence to kill, injure, capture or disturb bats or damage/destroy/obstruct access to a bat roost. Bat roosts are protected even when the bats are not present.

Our ecologists are fully licensed by Natural Resources Wales. They have considerable knowledge and experience that can guide you through this process.

Services we offer include:

  • Preliminary Roost Assessment.
  • Presence / absence activity surveys.
  • Transect and fixed-point surveys.
  • European Protected Species Licence (EPSL) and mitigation and compensation for the bats identified on site.
  • Ecological Clerk of Works – supervision on site during the development phase of a project to ensure that ecological and environmental impacts are avoided or mitigated.

Bat Surveys for Buildings and Structures

There are usually two stages to survey work. Stage 1 is a Preliminary Roost Assessment (PRA) which could lead to more detailed stage 2 activity surveys at dusk and dawn. Our ecologists can talk you through each stage and answer any questions you may have.

Stage 1 – Preliminary Roost Assessment

Bat Surveys
  • Can be carried out at any time of year
  • Ecologist will need access to exterior and interior of building/structure
  • This is the minimum requirement for bat surveys but may lead onto further work. 

Ecologists will be essentially looking for evidence of or potential suitability for roosting bats. This includes possible access points, evidence of signs of bats and quality of the surrounding habitat and connectivity to support bats.

Following the survey – if there is no bat roost potential a short report can be written to support your planning application. When a PRA has flagged up bat roost potential then activity surveys will have to be done between May-September and will need to be separated by at least 2 weeks.

Stage 2 – Presence / absence activity surveys also called Emergence (dusk) and re-entry (dawn) surveys

  • Can only be carried out from May to September
  • Designed to prove presence or likely absence of bats and/or characterise the roost
  • Usually 2 surveys, occasionally 3, will be undertaken depending on whether the potential for roosting bats is high, medium or low

Following the surveys – a detailed report will be produced using data gathered from stage 1 and 2 surveys and suggesting suitable mitigation measures. We may use static detectors placed in your building for a few days to provide further evidence of presence or absence of bats. This is possible in any of the stages mentioned above.

It is likely a European Protected Species Licence will be required which we can apply for on your behalf.