The average number of collision fatalities in different European wind farms on land varies between a few birds up to 64 birds per turbine per year (Langston and Pullan 2003; Everaert 2006a; Everaert 2007; see Table 1). Also within one wind farm, the impact can strongly differ between individual turbines (Everaert et al. 2002; Everaert & Stienen 2006), clearly showing that ‘site selection’ can play an important role in limiting the number of collision fatalities. …
Study results clearly show that reasonable amounts of birds and bats can collide with wind turbines. An exhaustive study before the selection of future locations is a key factor to avoid deleterious impacts of wind farms on birds and bats.
Cumulative negative impacts with an increasing amount of wind turbines must be taken into account (Langston & Pullan 2003). This especially is developing along fixed bird migration corridors (coasts, mountain passes). More wind farms also means an extra pressure on top of the already existing sources of negative impact (powerlines, traffic etc.). In a densely populated region like Flanders, this degrades the total suitability for ecological functions such as the presence of bird and bat populations and the guarantee for regional or international migration routes. For the offshore situation, international cooperation will be necessary to determine the possible cumulative impact.
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