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Wind farm impacts on birds

Wind farm development may have impacts on birds both during construction and once operational.

Well sited wind farms have limited effects on birds and our role is to guide development to the best locations. We also advise on assessing the effects and the guidance below provides further information for a range of effects and species.

Wind farms present three main areas of potential risk to birds:

  • death through collision or interaction with turbine blades
  • direct habitat loss through wind farm construction
  • displacement through indirect loss of habitat if disturbance causes birds to avoid the wind farm and surrounds

Displacement can include barrier effects in which birds are deterred from using their normal routes to feeding or roosting grounds.

You should consider each of the three types of risk above for every bird species that uses the site.

How birds behave close to wind turbines still isn’t well understood. Monitoring information on bird behaviour and collisions is available for some species, however.

Collision risk modelling

To measure collision risk, you should first assess how many collisions would occur in theory were birds to take no avoiding action. This should consider flight activity, bird size and speed, and turbine size and speed.

Next, you should apply an avoidance factor to reflect how, in practice, birds often manage to avoid a turbine blade. They may change their route, time their flight through the rotor or take emergency avoidance action.

Find out about:

Species-specific guidance

We regularly review avoidance rates and guidance for individual species.

View species-specific guidance:

We’ve also reviewed the need to conduct collision risk modelling for pink-footed geese in support of wind farm applications. In light of the robust population and its high avoidance rate of 99.8%, collision risk modelling for pink-footed geese is only required if a proposal has connectivity with a protected area where this species is a qualifying interest.

Read more in:

How to assess wider impacts

To help assess the significance of impacts of developments on birds in the wider countryside, view Natural Heritage Zone population estimates for 28 species of interest. These are available on page 72 of the Natural Heritage Zone Bird Population Estimates: SWBSG Commissioned Report No. 1504.

You may also find useful: Assessing significance of impacts from onshore windfarms on birds outwith designated areas.

How to assess impacts on Special Protection Areas

SNH has produced guidance to help you identify ‘connectivity’ between development proposals and Special Protection Areas: Assessing Connectivity with Special Protection Areas (SPAs) – includes dispersal and foraging distances for a range of bird species

Further guidance

Monitoring methods

Monitoring the impact of onshore wind farms on birds

Guidance on Methods for Monitoring Bird Populations at Onshore Wind Farms

Survey methods

Recommended bird survey methods to inform impact assessment of onshore wind farms

Breeding seasons for Scotland’s birds

Capercaillie Survey Methods

Assessment methods

A Review of Disturbance Distances in Selected Bird Species

Environmental Statements and Annexes of Environmentally Sensitive Bird Information: Guidance for Developers, Consultants and Consultees

Mitigation measures

Assessment and mitigation of impacts of power lines and guyed meteorological masts on birds

Dealing with construction and birds

Wind farm proposals on afforested sites – advice on reducing suitability for hen harrier, merlin and short-eared owl

Draft Scottish Natural Heritage/British Wind Energy Association guidance

We do not support the use of the SNH/BWEA draft guidance Assessing impacts of Wind Farms on Birds or any updates based on it. We didn’t finalise this draft guidance, as we weren’t satisfied that the approach complied with the Habitats Regulations 1994.

Report a bird collision

To report a bird collision with a wind turbine, fill in our bird collision reporting form. You should email your completed form to collision_records@nature.scot