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Development, climate change and habitat loss are major threats to bat populations and, although the UK is home to 18 species of resident bats, bat populations have declined considerably over the last century.
Development can have impacts including habitat fragmentation, changes to environmental conditions affecting foraging opportunities, and roost damage or loss. However, renewable energy developments – onshore wind in particular – can cause extra complications, leading to risk of collision, displacement and mortality. The severity of historic population decline means that all 18 species of bats present in the UK are now afforded high levels of protection, which developers need to be mindful of.
The legislation
Bats are a European protected species under the European Union (EU) Habitats Directives, and as such both bats and their roosts are legally protected in the UK. There are different pieces of legislation in England and Scotland to enact the Habitats Directive:
- England and Wales: Conservation of Habitats and Species (Amendment) (EU Exit) Regulations 2019
- Scotland: Conservation (Natural Habitats, &c.) Regulations 1994
Additional legislation to be aware of which are only applicable in England and Wales:
- Wildlife and Countryside Act 1981, as amended: this Act provides comprehensive protection for all bat species, making it illegal to intentionally kill, injure, or disturb bats, or to damage or obstruct their roosts (any place of shelter or protection), even when empty.
- Countryside and Rights of Way Act 2000: This Act provides strengthened protection for roosts and added “reckless” offences, covering significant disturbance likely to affect a species’ survival or distribution.
Survey types and dates
As bats are a species of principle importance during the planning process, UK planning guidance requires that developers consider the potential effects of onshore wind energy developments on bat populations and habitat through survey work, and develop mitigation strategies as necessary. The level of surveying needed will depend on the nature and scale of the proposed development. We recommend appointing an experienced ecological consultant early on in your project planning process to advise you.
For wind developments, there is clear and specific guidance detailing the required survey work for proposed development sites. A primary method for assessing bat activity levels for onshore wind development is ground level static monitoring. The minimum level of pre-application survey required using static detectors is for 10 nights of monitoring in three periods throughout the year. These periods are:
- Spring – April to May
- Summer – June to mid-August
- Autumn – mid-August to October
We generally deploy detectors for 14 nights in each period to account for weather variability and maximise the chances of a successful deployment. For sites in southern Scotland, the first 2 weeks in September is the peak window for carrying out autumn monitoring deployment surveying work.
Our Ecology team can undertake ground-level static surveys for wind development sites of up to 26 turbines. We use full spectrum detectors to monitor bat activities within development sites, indicating bat activity and recording the echolocation of passing bats. The collected recordings are then analysed using specialised software to determine species present and allow us to assess the level of activity within the site. In some cases, the data collected may indicate the need for further, more specialised survey techniques.
If high levels of bat activity are recorded on site, a number of mitigation methods are open to developers to manage and reduce impact on bats. This could include the incorporation of buffers around key habitat, smart curtailment using SCADA data, and blade feathering at low wind speeds, and the enhancement of creation of foraging habitat and linear features (such as hedgerows or treelines) away from the proposed turbines to support bat commuting and foraging activities within the site.
To assess potential impacts to bat roost and potential roosting habitats, preliminary roost assessments or ground level tree roost assessments are often required particularly for potential significant roosting habitat within 200m plus rotor radius for wind development and for habitat that may be lost to proposed development.
For solar or BESS developments, you may not require bat activity survey work, and current NatureScot guidance for solar does not require activity surveys to be undertaken. However, this will depend on the quality of habitat at your proposed site and within the immediate surroundings, scale of development / scale of potential habitat loss and local authority requirements. An experienced ecologist will be able to advise you regarding your obligations.
Key takeaways
Bats are an important species afforded high levels of protection, so it is important to assess any potential impacts of a development – particularly of an onshore wind development. When considering the need for, and extent, of bat surveys it is important to consider:
- the size, scale and type of development;
- the timing of works;
- desk study data;
- the potential nature and extent of impacts;
- if the effects will be temporary or permanent, over the long term or short term.
Failure to carry out adequate surveying or missing crucial survey windows can have serious consequences for developers. From delays to planning submission or having planning refused, to legal ramifications. Engaging an experienced ecologist to support early on in your development planning, and well ahead of key surveying season, can help to navigate these requirements and mitigate any potential stalls to your project.
Our Renewable Energy Planning & Environment team can help you with assessing the environmental impact of your energy developments ahead of survey season.
Contact our in-house ecology specialists today for support.