Scoping surveys

Bat scoping surveys are designed to identify any obvious signs of use by bats and assess how likely it is that the site could support bats.

The survey can be carried out any time of year.  It is undertaken during the day and includes carrying out a search of the building or structure for any evidence of bats; photographing and describing the building(s) surveyed; and looking for any cracks, crevices or other features where bats could roost without leaving evidence of their presence.  The information is written up and assessed in a report that also includes existing information about bats in the neighbourhood and details of the proposed development.

Whereas this is all that will be required for some sites, if the property has bat roost potential, emergence surveys may also be necessary even if no signs of bats were found.  This is because bats can roost in very confined crevices beyond which there may be no evidence of their presence.

If commissioning a scoping survey it is important to leave the buildings as they are.  Any cleaning, sweeping or other work that you may carry out could destroy evidence of bats.  This will mean that we will then have to carry out emergence surveys which could considerably delay your project.

Emergence surveys

Emergence surveys (also known as activity surveys) are carried out at night (either at dusk or dawn).  They can only be done between May and early September.

During these surveys observers watch the building(s) to look for bats entering or leaving.  These observations are recorded, along with the time, directions of flight, weather conditions, etc. in order to build up a picture of the bat use of the property.  Enough surveyors are needed to ensure that all aspects of each building can be observed at the same time and up to three visits to the site may be made to gather sufficient information.

The prime purpose of the survey is to determine any bat roosts present, the species of bat using them, the numbers and the type of roosts (maternity, male, non-breeding, feeding etc.).  This information then enables a mitigation plan to be drawn up.

Transect surveys

For some developments transect surveys are more appropriate.  These are most frequently used where a development is proposed on previously undeveloped land; examples may include a new housing development, new road scheme or wind farm proposal.

This type of survey involves one or more observers following a regular route around dusk or dawn and recording all bat activity encountered along that route.  The survey is then repeated on several occasions over several weeks or months to determine the types and numbers of bats using the site and what they are doing there.  This helps to assess the potential impact of the development on bats - e.g. loss of roost sites, feeding habitat, risk of collisions with traffic or turbine blades, etc. 

Specialist surveys

Specialist surveys can be devised for a wide range of purposes.  Surveys of autumnal swarming at cave entrances can indicate sites that are important for mating or hibernation and woodland surveys can assess the impact of management on bat populations.  We are always happy to discuss your requirements further.