Why do I need a bat survey?
All bats and their roosts are fully protected by UK law. This includes roosts that are not currently in use.
At Greenwillows Associates Ltd. our experienced team can advise you on the potential presence or absence of bats on or near your site.
Contact Greenwillows Associates Ltd. by clicking the ‘Contact Us’ button below or go to the main menu above.
What happens in a bat survey?
For projects where a roost is suspected, bat surveys involve two stages: a Preliminary Roost Assessment (PRA) and Emergence surveys. If your site contains suitable foraging or commuting habitat, which may be impacted, activity surveys will be required.
1. STRUCTURES
Preliminary Roost Assessment
On visiting your site our ecologist will establish likely absence or presence of bats from either trees or structures. A PRA can happen any time of the year. If any dropping are found, these can be sent off for DNA analysis.
Tree climbing / aerial inspection surveys are required to inspect Potential Roost Features (PRF) as ground level inspections can only make an estimate as to the status of a PRF.
A Bat Emergence/ Return to Roost Survey
Bat Emergence / Re-Entry Surveys are dusk or dawn surveys conducted using specialist equipment, including bat detectors and infra-red cameras to observe the potential exit or entry points of a roost for bats.
Surveys are restricted to the months between May and September (read our free survey calendar) when bats are most active, with often multiple surveys required.
Hibernation Surveys
• Inspection
Two internal inspections of each structure with potential for hibernating bats is undertaken between December and February at least four weeks apart.
• Automated/ Static Survey
Static remote bat detectors are placed within suitable structures on site to gain information on if/how features are used by bats and are left in place to record for 14 nights each month between November and March respectively.
2. TREES
Ground Level Tree Assessment (GLTA)
Assessing a tree from the ground for their potential to be use used by roosting bats. Potential roost features (PRF) and any evidence of bat use is noted. This will advise any further surveys.
Aerial Inspection Surveys
Trees assessed as Further Assesment Required (FAR) will require one aerial inspection survey to fully detail PRFs present and look for evidence of bats. This can be undertaken at any time of the year.
Any tree assessed as PRF-I will require no futher survey ahead of planning application, but will require precautionary methods ahead of any works/felling.
Any tree assessed as PRF-M will require three aerieal inspection between May and September, with at least two between May to August.
Emergence Surveys
These are only carried out if aerial inspections cannot be undertaken on the tree. Methods for these surveys is detailed in the Structures section above.
3. HABITATS
Activity Surveys
• Activity Transects
Bat activity survey involves a combination of Night-time Bat Walkover surveys and automated/static surveys to assess bat use of the habitats present at site for commuting and foraging.
• Night-time Bat Walkover
Night-time bat walkovers involve walking the site at dusk and dawn to record all bat activity. This is to gauge the impact of the project on bat foraging and commuting habitat. Typically these surveys are for larger developments, or developments that will impact on bat commuting / foraging habitat.
• Static Monitoring
Static monitoring involves placing devices with microphones for longer periods within key habitats to detect bats, such as hedgerows and tree lines.
Both surveys are designed to identify important areas of the site so that suitable mitigation can be advised to support the design of the project.
Taken from Bat Survey Guidelines for UK Homeowners (CIEEM)
BAT REPORT
The survey results are presented within an Ecological Impact Assessment (EcIA) report or a species specific assessment report. Our report will recommend mitigation and compensation measures for your project. We may highlight your development needs to take place at certain times of the year, the use of certain materials and/or specific provision to allow bats to continue to use the original or replacement roost.
Bat Mitigation – what is involved?
Our report will detail mitigation measures, which will include the need to obtain a mitigation licence if your work is going to impact bats that would otherwise be illegal. If this is the case the report will set out if you need a mitigation licence to carry out the recommendations.
Our team can assist you in the application process: including the preperation of licence applications and supervision of their implementation, and guidance on different licensing options. These include European Protected Species Licence (EPSL), ‘low impact’ bat mitigation class licence (BMCL) and bat earned recognition class licence (BER). Go to the Mitigation Licence webpage for further details.
For further information and advice click the ‘Contact Us’ button below.
