Bat surveys

An introduction to bat surveys

All bats in the UK are afforded full protection under UK and European Legislation including the Wildlife and Countryside Act 1981 (as amended) and the Conservation of Habitats and Species Regulations 2017. Together, this legislation makes it illegal to:

  • Intentionally or deliberately take, kill or injure a bat
  • Damage, destroy or obstruct access to bat roosts
  • Deliberately disturb bats.

A bat roost is defined in the legislation as “any structure or place which a bat uses for shelter or protection”. Roosts are protected whether or not bats are present at the time.

Local authorities and decision makers in England are guided by the National Planning Policy Framework (NPPF) which sets out the Governments planning policies and how these are expected to be applied within a local planning policy framework. The NPPF states that the planning system should “contribute to and enhance the natural and local environment by …minimising impacts on biodiversity and providing net gains in biodiversity where possible”.

Planning Authorities generally have a validation list and the requirements of this list need to be met prior to any planning application being validated. Commonly these validation lists contain some trigger for a wildlife survey, sometimes referred to as a Preliminary Ecological Appraisal or a Phase I Habitat Survey for proposals that impact on habitats. In addition to the habitats on a site being assessed for their botanical value the potential for protected species to be using a habitat is assessed during this survey. In some cases, dependent on the location of the site, the suitability of the habitats present (assessed at the time of the survey as being either Low, Medium or High value) and the potential impacts of any proposed development further bat activity surveys may be required.


Bat roost surveys

If the proposals impact on a building or roof structure then this can trigger the requirement for a bat roost survey. Initially a Preliminary Roost Assessment will be completed following current best practice guidelines. This survey must be completed by a suitably licensed ecologist (i.e. they must hold a valid Bat Class Licence). The structure will be inspected both externally and internally and any potential features with suitability for bats and/or actual signs of bats will be noted. The structure will then be assessed for its potential to support bats (either Negligible, Low, Medium or High).


Nocturnal bat activity surveys

Depending on the results of the preliminary surveys further nocturnal activity surveys may be required. Nocturnal bat activity surveys are time dependant (they can only be undertaken between the months of May to September) and the survey effort is dependent on the assessment of potential that the habitats present or a structure has. In many cases more than one surveyor is required to complete these surveys and often they need to be undertaken over a number of months in in each season (i.e. spring, summer, autumn) to provide an overview of activity. This can lead to delays for any planning submission as generally local Authorities require all surveys to be completed prior to validation.

Once all required surveys are completed the results will inform the level and type of mitigation required. Mitigation can range from avoidance measures (timing of works, alteration to the designs to avoid impacts to roosts etc) right through to the gaining of a European Protected Species Licence (sometimes called a derogation licence) or registration of the site by a Registered Consultant under the Bat Low Impact Class Licence (BLICL) system. The complexity and type of mitigation required will depend on the conservation status of any roosts found. In addition, in order to assess the likely impacts of proposals on bats and as part of the licence process it is necessary to consider whether or not the species concerned are maintained at a Favourable Conservation Status (FCS).

The Habitats Directive (92/42/EEC) states that the conservation status for species is taken as favourable when:

  • Population dynamics data on the species indicate that it is maintaining itself on a long-term basis as a viable component of its natural habitats, and
  • The natural range of the species is neither being reduced nor is likely to be reduced for the foreseeable future, and
  • There is and will probably continue to be a sufficiently large habitat to maintain its populations on a long term basis.

Natural England (the Statutory Authority who assess licence applications in England) may in some cases refuse to grant a licence if it cannot be illustrated that the favourable conservation status of the species is not maintained as a result of any proposals.


Greater Horseshoe Bat Surveys

Additionally, we have a substantial proportion of the UK population of Greater Horseshoe bat in Devon. This large and very rare bat can be found on numerous sites in the South Hams and these sites collectively form the South Hams Special Area of Conservation (SAC) and receive European Protection. As part of the South Hams SAC there are designated flyways (routes along which these bats fly to and from roost sites and feeding grounds) and sustenance zones (areas that these bats rely on for food) and if a proposed development site falls within one of these areas and is of a certain type and size additional survey effort must be undertaken.


Bat Survey licences at Burton Reid

Burton Reid Managing Director, Jenni Reid, holds a Class 2 bat licence which enables her to survey for bats, disturb bats and handle bats. Jenni is also a Registered Consultant under the BLICL scheme and has successfully gained numerous EPSL on behalf of clients.

Please do give the office a call and one fo the team will be happy to talk things through with you. 


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