Protected Species Survey: Bats

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All UK bat species are fully protected under the Wildlife and Countryside Act (1981) as amended and the Conservation of Habitats and Species Regulations 2017.


Initial survey

During a Preliminary Ecological Appraisal (PEA), our licenced ecologists will undertake a Preliminary Roost Assessment of any buildings or trees within a site. This includes a visual search for droppings, scratch marks, staining, and food debris, as well as assessing the structure’s suitability for roosting bats.


Further surveys

Our in-house arborist means NWS also offers aerial inspections of trees. A thorough inspection of potential roost sites may mean we can rule out the need for nocturnal surveys.

Based on a structures suitability for roosting bats, up to three nocturnal bat surveys may be required. These involve recording bats returning (at dusk) and emerging (at dawn) from the site, and are restricted to the bats active season between May and September.

Where important foraging and commuting habitat has been identified, our ecologists recommend bat activity transects. This involves surveyors walking a set route at dawn and dusk recording bat activity.

All bat surveys are undertaken by licenced ecologists, accompanied by acoustic detectors and recorders to aid identification.

Where structures are identified as providing a stable, cold and humid environment that allows bats to go into deep torpor during colder months, hibernation surveys maybe required. These take place between December and February and involve searching buildings with an endoscope.



Once surveys are complete, a full impact assessment of the proposed development on bats is made and an appropriate mitigation strategy devised. This might involve a Method Statement for work to prevent disturbance or damage to roosts, or, where destruction of roost is unavoidable, a European Protected Species Licence (EPSL).