The spring and summer bird and bat survey seasons are approaching fast, and surveys for these species are seasonally constrained.
There have recently been changes to the suggested approach to wind farm bird survey in England, with the publication of Natural England (NE) guidance in early 2010. Potential impacts on bats – very much the emerging issue with regard to terrestrial wind farms – have to date been difficult to assess due to the lack of standard survey guidance and limited information on bat populations.
Further guidance is anticipated in mid-2011 when the Bat Conservation Trust issues updated guidance on bat survey protocols: this will include a section on bats and wind farms.
Bird Surveys for wind farms
The breeding bird season typically extends between late March and July for most species. Scottish Natural Heritage (2005) and NE (2010) guidance both detail the vantage-point survey (VP) requirements at wind farm sites. The SNH guidance is a far more detailed and substantive document than the NE equivalent, but the approaches to baseline bird survey that are advocated are very similar. Differences in guidance reflect the fact that many Scottish wind farm proposals have traditionally been in open (often remote) moorland landscapes (where birds are relatively detectable over large distances), while in England lowland, relatively enclosed, farmland sites are often chosen.
In addition to Vantage Point surveys, depending on the habitats present on a site, a walkover survey based on the Common Bird Census (CBC) methodology, a Moorland Bird Survey (following the Brown & Shepherd methodology), or a lowland wader survey (based on the O’Brien & Smith methodology) may also be required to identify breeding species and central territory locations. Wetland areas and woodland blocks will require additional (often small scale) specific work, while the potential for specially protected raptors (birds of prey), black grouse and a range of other species to occur can be easily assessed by a suitably experienced ornithologist before site work commences. Surveys for many of these species begin in April.
We anticipate that, upon release of the BCT Guidelines in mid 2011, the amount of baseline bat information routinely required to inform wind farm applications could increase.
At present, due to the lack of established protocols, many wind farm applications are informed by reference to the current, more generic bat survey guidelines (which clearly state they are not intended for wind farm developments), and the guidance from Natural England; this provides general survey advice but does not include prescriptive requirements.
These current guidelines advise a minimum effort of a few walkover surveys, which may be supplemented by information from one or more static data loggers (e.g. Anabats) to provide a baseline for assessment of impacts of development.
While currently no-one can be sure exactly what the forthcoming guidance will require, monthly walked transects between April and October are likely to be required on most English and Welsh sites. For Scotland the survey season is likely to remain shorter, reflecting the fact that April and October are colder than in the rest of the UK, and that bat activity in these months is likely to be more limited.
There may also be a greater emphasis placed on the use of static data loggers, with sampling required in each month across the period, including the use of sample points which targeting turbine locations.
It is also possible that the scoping out of bat surveys, even in open arable landscapes with few linear features, will become increasingly difficult for any wind farm proposal of more than a single turbine.
- Natural England (2010) Technical Information Note TIN069: Assessing the effects of onshore wind farms on birds.
- Natural England (2009) Technical Information Note TIN051 – Bats and onshore wind turbines Interim guidance.
- Scottish Natural Heritage (2005) Survey methods for use in assessing the impacts of onshore windfarms on bird communities (revised December 2010)
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