Bat Surveys

Ecology

There are 16 species of bats in the UK. Bats roost individually or in colonies, feeding 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, suburban gardens and well-lit urban open spaces.

Survey Methods

Several bat survey methods can be used to determine the presence of bats or a bat roost. A licenced ecologist is required to undertake these surveys.

• Walkover survey for buildings / building inspections: All areas of a building are searched for signs of bats, evidence includes bat droppings and food remains. Building structures are also searched for potential bat entrance holes.
• Walkover survey for trees and woodland / ground based tree assessments: This involves searching trees and woodland for potential roost sites such as mature trees, peeling bark, tree splits and dead trees.
• Bat Detectors: This involves using special equipment designed that a surveyor can hear bat echolocation calls at a frequency which is audible to them.
• Emergence Survey (dusk emergence and dawn return to roost surveys): This type of survey occurs at dusk or dawn with observers in particular positions around a survey site to record any bat activity.
• Transect Survey: This type of survey is used for conducting a bat survey in open areas with no buildings.

Protection & Legislation

Under the Wildlife and Countryside Act 1981, the Wildlife Order (NI) 1985 and the Habitats Regulations 1994 (and NI 1995) it is illegal to:

• Intentionally or deliberately kill, injure or capture bats;
• Intentionally, deliberately or recklessly disturb bats;
• Intentionally, deliberately or recklessly damage, destroy or obstruct any place used for shelter or protection, i.e. bat roost (even if they are not currently occupied)
• Possess, sell or transport a bat, or anything derived from it.

Licensing & Mitigation

Any development works that will impact bats or bat roosts will require a development licence from Natural England or Welsh Assembly Government. A development licence will only be granted if a suitable mitigation plan has been written by a suitably qualified ecologist.

Mitigation measures typically include:

• Provision of artificial roosts
• Construction of bridges and underpasses
• Planting of vegetation to provide feeding habitat
• Linear planting to provide flight corridors
• Careful design of lighting
• Post-development monitoring

Contact Abricon for free initial advice on bat surveys