environmental consultancy

T+44(0)1275 391 297 E ecology@abricon.com

Bat Surveys

Bat Ecology

There are 17 species of bat resident and breeding in the UK. Bats roost individually or in colonies, feeding on insects at night and roosting during the day. Suitable roosting habitat includes buildings, bridges, quarries, trees, cliffs and caves; whilst suitable foraging habitat includes woodland, scrub, parkland, farmland, hedgerows, wetlands, waterways and suburban gardens.

Protection and Legislation

In the UK all bat species are fully protected under The Conservation of Habitats and Species Regulations 2010 and the Wildlife and Countryside Act 1981 (as amended).

It is an offence to;

  • Deliberately capture, injure or kill a bat
  • Disturb a bat in a place of shelter or rest
  • Damage or destroy a bat roosting place (even if bats are not occupying the roost at the time)
  • Obstruct access to a bat roost
  • Possess or advertise/sell/exchange a bat (dead or alive) or any part of a bat

Operations which could affect bats may require a development licence from the appropriate statutory organisation prior to the start of works.

Survey Methods

Depending on the nature of the site, there are a number of survey methods which can be employed to determine whether bats are present, and how they are using a site. A licensed ecologist is required to undertake these bat surveys.


  • Phase 1- Daytime building inspection: The building(s) would be inspected internally and externally for any evidence of bats, such as droppings, staining and/or bats themselves. Where no bats are found, the building(s) would be assessed for suitability to offer potential roost sites for bats. Building inspections can be undertaken at any time of year.
  • Phase 2- Night-time emergence surveys: If there is potential for the building(s) to house bats, or evidence of bats, then additional surveys in the form of dusk/dawn activity surveys will be required in order to assess the bat population status and their location within the building(s) (if present). Emergence surveys are seasonally constrained to between May and September.

Land parcels

  • Ground level tree assessments: Individual trees or areas of woodland will be searched for potential features which could be used by roosting bats such as; woodpecker holes, lifted bark and trunk cavities. This survey can be undertaken at any time or year.
  • Transect Survey: This type of survey is used for conducting a bat survey across a site, and involves surveyors walking a route for a set amount of time and recording any bat activity. They can be undertaken between April and October when bats are active, and must be spread across the season.
  • Remote monitoring surveys: This survey is often used in conjunction with transect surveys for monitoring sites. It involves placing bat detectors at strategic points across the survey site and leaving them in situ for 5 or more nights at a time to record any bat activity. They can be undertaken between April and October when bats are active, and must be spread across the season.

Licensing and Mitigation

Works which will impact upon bats may require a derogation licence to be obtained from the appropriate statutory body for nature conservation prior to the start of works. A mitigation licence permits operations which would otherwise constitute an offence and will only be approved if it includes a suitable mitigation plan and is completed by a licensed bat ecologist.

Survey calendar for Bats

Survey calendar for bats

Mitigation calendar for Bats

Mitigation calendar for bats

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Telephone +44(0)1275 391 297 Email ecology@abricon.com

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