Bat Surveys

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Bat Surveys

We can undertake Bat Surveys for planning applications…

We have 17 species of bats in the UK, all of which are entirely insectivorous and nocturnal. Bats roost in a variety of structures including houses, barns, trees, caves, bridges and mines.  They use different roosts at different times of the year depending on their behaviour, e.g. raising young, hibernating, mating etc.  A roost is defined as any place used for shelter or protection.


Survey Types & Timing

Bat surveys are generally split into two categories; daytime inspections/daytime bat surveys and activity surveys (dusk and/or dawn surveys). The daytime inspection can be undertaken at any time of year and can include a barn owl survey if also required. It involves assessing a structure for evidence of or potential for bats.  Activity surveys are carried out depending on the findings of the daytime inspection; these surveys entail directly monitoring bat activity at night and are undertaken generally between May – September, when bats are at their most active.

If you are developing on a plot of land (e.g. a housing development, road scheme etc) you may need a series of activity surveys throughout the summer. These generally involve walking predetermined transects around boundary features such as hedgerows and tree lines, to identify important bat commuting routes and foraging areas.  Bat surveys, which involve assessing potential bat roosts (e.g. buildings, trees etc), should be undertaken by suitably licensed ecologists.

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Legislation & Planning

All British bats are protected under the Wildlife & Countryside Act 1981 (as amended) and the Conservation of Habitats and Species Regulations (2010). This makes it an offence to:

  • Deliberately capture, injure or kill a bat
  • Intentionally or recklessly disturb a bat in its roost or deliberately disturb a group of bats
  • Damage or destroy a bat roosting place (even if bats are not occupying the roost at the time)
  • Possess or advertise/sell/exchange a bat (dead or alive) or any part of a bat
  • Intentionally or recklessly obstruct access to a bat roost

Local Planning Authorities are obliged to request bat surveys to accompany planning applications where they believe there is a reasonable likelihood that bats are present, whether it is a commercial development or a householder application, e.g. for a loft conversion or extension.


The Next Step

If a bat roost is present it may be possible to avoid committing an offence by changing the timings of the work (assessed on a case by case basis) or altering the proposed design.  If it is not possible to avoid committing an offence then a European Protected Species (EPS) development licence will need to be applied for from Natural England; this allows work to proceed that would otherwise be illegal.  Applying for a licence involves a written application accompanied by a full site assessment (presenting the findings of the bat surveys) and detailed mitigation plan. Before approving a licence application, Natural England must be provided with enough information from the surveys to satisfy them that the following three tests are met:

  • The consented operation must be for “preserving public health or public safety or other imperative reasons of overriding public interest including those of a social or economic nature and beneficial consequences of primary importance for the environment”; and
  • There must be “no satisfactory alternative”; and
  •  The action authorised “will not be detrimental to the maintenance of the population of the species concerned at a favourable conservation status in their natural range.