Bat surveys
Domestic and European legislation protects all 18 species of bat in the UK
As bats roost in buildings and trees, they are easily affected by development or maintenance work. If there is a reasonable chance bats might be present, it is highly advisable to conduct a survey before starting work. Bats can roost in trees, buildings, caves, tunnels, bridges and other structures if there is suitable habitat nearby for them to forage.
Our ecologists hold protected species licenses and are accredited to undertake bat surveys. If they are present, we will advise on what to do next. We have extensive experience in delivering projects ranging from uncomplicated building extensions to major housing schemes.
Our team also includes trained tree climbers who can safely conduct climbed tree inspections for bats.
How are bats protected?
Regarding the protection of bats, it is illegal to
- disturb a bat or groups of bats in their roost
- damage or destroy a bat roosting place, even if there are no bats present at the time
- obstruct access to a bat roost
- capture, injure or kill a bat or possess, advertise, sell or exchange a bat or part of one dead or alive.
Bat surveying
Most bat surveys are undertaken between April and September when bats are active. Surveys can include dusk emergence/dawn re-entry surveys and activity transects. Buildings may require multiple visits if there is a high chance bats are present.
It is possible to check for bats at any time of the year with building inspections and ground-level tree assessments. These checks will look for any evidence of bats, such as droppings. It will also highlight any internal or external features like cracks or gaps which bats could use. Hibernation roost checks can also be undertaken during the hibernation period from December to March.
Survey calendar
Activity (bat surveys): April – September, emergency re-entry: May – August and hibernation roost checks: December – March.
If bats are present
If bats are on site and impact is unavoidable, the applicable Statutory Nature Conservation Organisation (SNCO), e.g., Natural England, will need to issue a European protected species mitigation license. Our ecologists can do this on your behalf.
The mitigation required will depend on how the works impact the roost and the time of year. It may include
- creating replacement roosting opportunities
- developing sensitive lighting strategies
- installing a bat corridor (pictured) as a new route to feeding
- creating suitable foraging habitat.
Mitigation calendar
- January – February: Works to maternity roots only
- March – April: Hibernation and maternity roots
- May – August: Works to hibernation roots only
- September – October: Hibernation and maternity roots
- November – December: Works to maternity roots only
*Please note the process for getting a European Protected Species Mitigation (EPSM) Licence can take some time. It requires recent survey work and that is seasonally constrained.
