Fledermausschutz Fehlende Betriebssteuerungen an alten Windenergieanlagen können hohe Schlagopferzahlen bei Fledermäusen verursachen.

Curtailment measures for the protection of bats around wind turbines (WT) have only been practiced since the corresponding guidelines were established more than 10 years ago. About two thirds of onshore WT were commissioned before then and therefore operate without curtailments. As a model, we estimated the number of bat carcasses at two old WT that have been operating since 2001 without curtailment on a plain arable field. We found 37 carcasses during systematic searches conducted over a two-month period. An experiment revealed that 95 % of all carcasses were removed by scavengers within 24 hours. Accounting for carcass removal and search efficiency suggested that several hundred bats were killed at the focal WT during the study period. For comparison, we conducted identical surveys at recently installed WT that operate with curtailments to protect bats. We did not find any carcasses at these WT, although we expected a high collision risk for bats at this site because of the forest structure. Our study underscores that old WT operating without curtailment can generate high numbers of casualties even on open farmland sites. Curtailment procedures should be implemented as soon as possible for old WT to stop the recently observed population declines in high collision risk species. [ABSTRACT FROM AUTHOR]