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The UK is home to 17 native species of bats, one of which was considered extinct until an individual was found hibernating in southern England in 2002. All of our native species are small, insectivorous bats that can be found from towns and cities to forests and farmland. Bats are extremely mobile and use systems of echolocation to help them to navigate and find prey. Bats use roosts as their places of shelter of which there are several types including maternity, hibernation, mating, transitory and other areas such as feeding perches and swarming sites. Bats may roost in trees, houses, cellars, churches, caves and a variety of very interesting places. Bats will generally mate in autumn and then hibernate over the winter months, waking on occasion to feed or move hibernation site but start to become more active in February. Females delay fertilisation until Spring and give birth around June or July usually to a single baby.




Bats are highly mobile animals and will regularly move between roosts over the course of the summer, and even through their winter hibernation period. In order to determine the presence or absence of bats, several techniques may need to be implemented at appropriate times of the year. An initial desk based study is recommended to acquire historical records of bats and bat roosts in the local area, and to identify any potentially suitable habitat or statutory designated sites. This information will inform the survey technique and survey effort.




Structures may be assessed at any time of the year for the presence of bats, although it is illegal to enter a known roost and any work pertaining to roost visits should be carried out by a licensed individual. Structures that may require a survey include:


  • Buildings

  • Trees

  • Culverts

  • Tunnels

  • Bridges


Structural surveys will help to identify potential access points and roosting areas for bats. These surveys can also identify indirect evidence of bats such as droppings, oil stains and feeding remains that would indicate bats use the structure. The type of species and population numbers can assessed to a limited degree using indirect evidence, however bats may also be present during the survey and population numbers may be estimated and identification of species can be made more accurately. 




Climb & inspect aerial tree surveys are a very useful tool that can be undertaken throughout the year to survey trees. They provide huge savings on traditional activity  surveys (see below) and can be scoped out with a single survey. 


See the AERIAL TREE SURVEY page for more details




If further investigation is needed into the use of a structure by bats,  activity surveys may pick up on valuable information that a building inspection alone would not identify. Ideally at least 3 activity surveys should be undertaken at a potential roosting structure, which should include an emergence survey and a re-entry survey within a 24 hour period. The types of activity survey include:


  • Emergence (dusk) Surveys

  • Re-entry (dawn) Surveys

  • Transect Surveys


We provide licensed bat workers to professionally undertake all survey and mitigation work. If you require a bat survey, contact us and we will be happy to help.



The legal protection afforded to bats will prevent a planning application unless the relevant Statutory Nature Conservation Organisation are satisfied that their criteria for a protected species licence are met. Sufficient survey effort is essential for a licence application and the intensity of surveys and time period over which they are carried out will vary according to the site. Appropriate mitigation will be required which will replace the pre-existing area used by bats. The more appropriate mitigation and compensation the better the general success rate of licence applications. Licences in England are issued by Natural England and may take up to 30 working days to process so factoring this timescale into a project is essential to prevent costly delays.




There are 17 species of breeding bats native to the UK, all of which are afforded the highest level of protection under national and European legislation. Bats are protected under the Wildlife and Countryside Act 1981 (as amended), the Conservation (Natural Habitats &c.) Regulations 1994 and European legislation such as the Habitats Directive 1992. This makes it illegal to capture, kill, handle or sell bats or to damage, destroy or obstruct a place of shelter used by bats, even in the absence of bats at the time.


1: Bats are a Material Consideration!


The National Planning Policy Framework (2012) reminds local planning authorities and developers that important species and habitats (including those included in the UK Biodiversity Action Plan and Local Biodiversity Action Plans) occur outside of protected sites and can be a material consideration in planning. Parts of this framework have now been superseded by the Natural Environment and Rural Communities (NERC) Act (2006) which amends the duty on all public bodies to conserve biodiversity and in particular amends the list of species and habitats of principal importance for biodiversity conservation in England and in Wales.


2: How Do I Get the Surveys Done?


Contact us! Or at least contact your local ecologist. Find recognised ecologists in the CIEEM directory in your local area (see USEFUL LINKS). Your friendly ecologist should hold a relevant personal class licence from Natural England or the relevant Statutory Nature Conservation Organisation (SNCO) e.g. Natural Resources Wales to work with specific protected species. Show them your requirements, see what they recommend, ask for their timescale and get a quote! Also ask as many questions as you can, we're here to help conserve our natural environment, but we're also here to help you get through planning!


3: Early Planning is Essential


Things get very busy for ecologist in the summer, so be sure to plan well in advance. Always ask your planning authority if any ecological surveys are required for your development. Far too often this will be red flagged at the 11th hour (often during Autumn), when the survey season has ended. This can cause delays of up to a year, so its well worth thinking ahead! See our Works Calendar


4: The Amount of Survey Effort


Depending on the findings of the initial survey, several things may happen. No evidence of bats may be found, and the site may be considered unsuitable for bats and no further survey effort may be required. Alternatively, the site may provide good potential for bats (e.g. good habitat or potential roosting areas), in which case further survey effort is required on a phased approach. If evidence is still not found, then no further work is likely, Finally, if evidence of bats is observed, then a full suite of surveys is recommended as this will probably mean you need to apply for a licence. Essentially, we won't know how much survey effort is truly required until an initial scoping survey has been undertaken, although we can estimate the liklihood based on your site.


5: You Might Need a Licence to Disturb Bats


Due to their level of protection, any form of disturbance to bats, or damage to their roost sites (even if they're not present) may constitute an offence un UK and European law. In order to undertake a development legally, a European Protected Species (EPS) Licence may be necessary to allow otherwise illegal activites to be undertaken. Before an EPS licence can be sought, sufficient survey effort is necessary to understand the types of roost, the number of bats present and the species using the roosts. Sometimes this can take a whole season, or even several seasons to get sufficient information if the roost is large or important (e.g. a maternity roost for rarer species). For more information on licensing, see EUROPEAN PROTECTED SPECIES LICENCES and BAT MITIGATION CLASS LICENCES.


6: Do I Always Need to Apply for a Licence if I Have Bats?


It depends. Is the development likely to damage, destroy, or obstruct a roost? WIll the development disturb, injure or kill bats? If so, then the answer is probably yes, although this is not always the case as there are some exceptional circumstances. However, the works can be sometimes be completed by creating an ECOLOGICAL MANAGEMENT PLAN (EMP) where the development can avoid impacting upon bats or bat roosts by the timing of work, and specific precautions that can be put in place. An EMP alone should only be considered once sufficient survey effort has been undertaken and there will be no conflict with UK and European wildlife law. An EMP cannot be used alone if, for example a roost is being destroyed (e.g. house demolition) or if bats will be actively disturbed (e.g. works can only be done in the bat activity season).


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