Effects of Individuals Lost Due to Wind Turbines on the Time of Occupying a Territory, the Survival of Breeding Territories and the Breeding Success of White-Tailed Sea Eagles (Case Studies)

Abstract

By means of case studies, nature and extent of the effects of individuals lost due to wind turbines on establishment and survival of breeding territories and the breeding success of the white-tailed sea eagle are presented. By identifying individual colour rings and collection of moulted feathers, the individual breeding birds and the breeding success (number of fledged young birds) is known for many breeding birds in Schleswig-Holstein. Three of the 26 collision victims in Schleswig-Holstein could be allocated to local breeding pairs. Impacts of individuals lost due to collisions with wind turbines vary in severity between none at all (case 3), one year of delay in establishing a breeding territory (cases 1 and 2) or permanent abandonment of the territory for the time being (case 4). Case studies from Schleswig-Holstein indicate that white-tailed sea eagles are especially prone to collisions in the time of establishing a breeding territory. Between 1993 and 2011, 26 collisions of white-tailed sea eagles were recorded in Schleswig-Holstein. 19 of these birds were ringed. Of the total of 13 collisions, which could be attributed to a breeding site (8 breeding birds, 5 first year birds), seven occurred within the protection zone (radius 3 km declared by the Working Group of German State Bird Observatories).