[kshotton45]

I found this - it's from a report by the Danish Wind Turbine Manufacturers Association, so it may be a bit biased.

Birds and Wind Turbines

Concern has been expressed in newspaper articles and by some bird lovers that wind turbines could be a danger to migrating birds and some even go so far as to call them ‘mincing machines’. Birds often collide with high voltage overhead lines, masts, poles, vehicles and the windows of buildings. Do wind turbines, with their large rotating blades, pose an even greater threat?

Studies of birds and wind turbines
According to the Danish Wind Turbine Manufacturers Association, birds are seldom bothered by wind turbines. Radar studies at a 2- megawatt wind turbine with 60 metre rotor diameter show that birds – by day or night – tend to change their flight route 100-200 metres before the turbine and pass above it at a safe distance.

There are several examples of falcons nesting on cages mounted on wind turbine towers.

The only known site with major bird collision problems is the Altamont Pass in California, which has a great number of lattice-tower type turbines. This has the effect of closing off the pass and bird kills from collisions have been reported.

Some birds get used to wind turbines very quickly; others take longer. The possibilities of siting wind farms next to bird sanctuaries therefore depend on the species in question.

Bird studies from the Yukon show that migratory birds do not collide with wind turbines, but migratory routes of birds will usually be taken into account when siting wind farms.

A study from the Danish Ministry of the Environment says that power lines, including those leading to wind farms, are a much greater danger to birds than the turbines themselves.

Studies from the Netherlands, Denmark and the US show that the total impact on birds from wind farms is negligible compared to the impact from road traffic.
A three-year study, carried out by the National Environmental Research Institute at Kalo, Denmark, concluded that offshore wind turbines have no significant effect on water birds. The overall conclusions from a series of experiments were that the eiders keep a safe distance from the turbines but do not get scared away from their foraging areas by revolving rotors. Also, the eiders showed normal landing behaviour until 100m from the turbines.

“Impact Assessment of an Off-shore Wind Park on Sea Ducks, NERI Technical Report No. 227"

Birds and planning
An environmental impact assessment was carried out before permission was granted for four wind turbines to be erected in an industrial area of Great Yarmouth. A part of that assessment looked at the impact on local bird life.
English Nature guidelines recommend that wind energy projects should be sited at least 800m from areas of high ornithological interest, away from bird migration routes and features attracting high densities of birds.

The study notes that the proposed wind park has been sited 4-6km away from both Breydon Water SPA/SSSI and Great Yarmouth North Denes SPA/SSSI. It is also sited away from migration routes and features attracting high densities of birds. Notable species of birds such as Bewick’s Swan, Ruff, Cormorant, European White-fronted Goose, Wigeon, Golden Plover, Common and Little Terns are identified, together with their use of the area (e.g. for over-wintering, breeding, and roosting). The movement of bird species for breeding, feeding and roosting and also migration routes are taken into account to assess the impact of the wind farm on local bird populations.

The report concluded that the siting of the proposed wind park would not affect the feeding, breeding or migration of the notable bird populations of these two sites.

The combination of evidence that in general birds are not affected by wind turbines, together with care taken over the siting of wind farms near sensitive areas should ensure that birds are not under threat from developments.