Bat Surveys

Over the last century bat populations have suffered serious declines and are currently under threat from factors such as the loss of feeding habitats and flight paths e.g. hedgerows, woodlands and ponds; loss of prey through the extensive use of pesticides having a detrimental effect on insect numbers and through building and developments destroying and damaging roost sites. To ensure the conservation of biodiversity it is recommended that developments adhere to regulations and that an appropriate ecological bat survey is conducted to assess the impact on bat populations.

Initial Assessment for Bats

Before any development works commence an initial assessment of the area, such as a building, structure or tree, to identify any actual or potential sites for bat roosts should be conducted.

We will produce a report, suitable for submission with your planning application, highlighting any potential impacts on bat species. If there is a bat presence we would suggest practical mitigation solutions. If any evidence of bats is found at this initial stage further surveys will be required.

Additional Bat Surveying

When existing or potential bat roosts have been identified a detailed assessment of the site is required by law if you wish to pursue a planning application. Various nocturnal bat surveys are necessary to establish the exact locations of bat roosts, the species of bats using the roosts and the number present at each roost.

When evidence is found of a site being an actual bat roost a licence application will need to be submitted to Natural England, which we can assist you with.

Bat Survey Methods

We have a choice of methods and technical tools available to undertake the ecological bat surveys.

Walk Through – Building Survey

All areas of the building are examined for physical evidence of bats such as droppings and food remains. They also look for potential bat roost entrance holes.

Walk Through – Woodlands and Trees

This involves an experienced bat ecologist searching the tree or woodland area for potential or used bat roost sites. This may be mature trees, peeling bark, tree splits or dead trees.

Bat Detectors

These machines allow the different echo location calls to be heard at a frequency audible to the human ear. Each bat species has a distinctive call and can be identified easily using this method.

Emergence Surveys

These surveys occur at dusk with a number of trained observers located in specific positions around the survey site to record bat activity.

Transect Surveys

These are used on open areas of ground without building structures.

Ecological Impact Assessment

Using the survey results any bats present, roosts, foraging areas and commuting routes will be valued and through an ecological impact assessment we will advise on the ecological effects of the project in terms of national, regional and local effects.

Bat Licence Application

Upon approval of planning permission if a licence has not been previously applied for the application will need to be submitted to Natural England before any development works commence. This requires a mitigation statement explaining what actions will be taken to preserve the bats and their roosts on the site during and after development. This application can take approximately four weeks to receive a response from Natural England so it is recommended that you plan ahead.

Bat Mitigation

Our suggestions may include some of the following:

Avoid works during sensitive times of the year, such as breeding season
Supervised demolition by a licensed ecologist
Installation of specially developed roof tiles which provide bat roof access points
Design and construction of replacement roosts
Installation of bat boxes or other artificial roosts
Construction of access routes such as a bridge or underpass
Recommended planting to create feeding habitat or flight corridors
Specialist lighting design
Post-development monitoring