Undertaking Bat Surveys for Development

As bats are a protected species, it is therefore an offence for anyone to intentionally capture, injure, or kill a bat. It is also illegal for a person to disturb, or destroy the habitat, shelter, or breeding place of bats. It is for this reason that a bat surveyor will be required for many planning applications.

Evidence of bats may have been previously determined at a site during a Preliminary Roost Assessment (PRA), where the likelihood of bats being present within a site is assessed.

During the PRA, ecologists search for field signs of bats, as well as potential bat roosting features where bats could be present. In addition, habitat suitability for bats is assessed, including foraging resources and the presence of any linear commuting features within the site.

Which Type of Bats are Likely to be Present?

Whilst many people assume bats hang upside down like you see on many documentaries, in the UK most species of bat are crevice dwellers. This means they tuck themselves into small gaps in structures. Long eared bats do hang upside down. It is a criminal offence to disturb bats, and therefore only ecologists with a Natural England bat licence should undertake surveys where bats are present.

Nocturnal Bat Surveys

Where there is a potential for bat species to be present within a site, and where the development proposals may have an adverse impact on bats, further nocturnal presence absence surveys or activity surveys may be required.

Nocturnal bat surveys involve surveyors using bat detectors to record and analyse bat calls in order to either gain information on the assemblage of bats within a site or determine the location of bat roosts.

Surveys can be taken at dusk and dawn. They will be either dusk emergence (when bats are leaving their roosts to forage) or dawn re-entry (the end of the night out when all the bats return back to their roosts). All surveys should be undertaken in line with Best Practice Guidance as set out in Collins (2018).

Will I Need a Survey for Development?

The local planning authority will usually advise when surveys are required, and all protected species surveys should ideally be completed prior to submission of a planning application. This is so that confidence can be gained that the development, if approved, can secure appropriate mitigating measures for any impact on bats.

Where are Bats Likely to Be Present?

In England and Wales, bat activity is usually found around woodland, or water areas, particularly those with features which help them commute, such as hedgerows and river valleys. They are also likely to be found in old buildings, warm roofs, or areas where there are caves or tunnels.

What Happens If Bats Are Found on a Development Site?

If bats are found to be present, local authorities will often request mitigation strategies to be a condition of planning, with measures such as installation of bat box or artificial bat roosts to mitigate. If any impacts on a bat roost are anticipated, a Natural England Mitigation Licence may be required for development to proceed.

Our Ecology Director, Olivia Collington, reminisces of a bat survey she undertook as a Graduate Ecologist in Greater Manchester near to a farm. Whilst the team had full access to the site, and landowners had been informed, the local farmer confronted Olivia and the team with a shotgun. Needless to say the surveyors made a hasty retreat. Other tales of bat surveys include being terrified of loud rustling in the bushes, getting ready to run – only to find it to be a very noisy hedgehog!

Can Bat Surveys be Undertaken at Any Time of the Year?

Bat surveys are a key part of an ecologist’s life, and the summer survey season can be hard work. However, ensuring species are protected through development and providing a positive lasting impact on the species where possible is the reason most ecologists entered the profession.

The bat survey season is between May – September, with surveys only being undertaken in suitable weather conditions. For some development sites where there is potential for bats to hibernate, surveys may be required throughout the winter months.

How Can Collington Winter Environmental Assist?

Collington Winter Environmental are a team of ecological consultants with extensive experience in undertaking bat surveys on all types of development projects. Our Ecology Director, Olivia Collington, holds a Natural England Bat licence, and has worked with protected species across the UK, undertaking field surveys and writing scientific, readable reports for submission at planning.

We adopt a pragmatic approach to all sites, working with clients to find solutions and develop relationships. With current offices located in Greater Manchester and Dumfries, the team are well served to work nationwide. Over the years, we have built strong relationships with key stakeholders across the UK.

Please get in touch with our Ecology Director Olivia Collington (Olivia.collington@collingtonwinter.co.uk) for more information on bat surveys and mitigation.