Long-term changes and breeding success in relation to nesting structures used by the white stork, Ciconia ciconia

Anthropogenic changes have strongly influenced the European landscape. In the last 50 years electric power-line networks have become a conspicuous part of that landscape. From the outset it was known that these lines and their support structures would cause fatalities in the white stork, Ciconia ciconia. From a long-term (1983-2006) study in Poland, we analysed breeding performance in stork nests on four types of structure (chimneys, roofs, trees and electricity poles). Whilst the numbers of nests on both electricity poles and chimneys have increased, there was no significant difference among the four structures in terms of breeding success. Since 1998, over 100 electricity poles in this white-stork breeding area have been modified to include a platform designed to accommodate a stork nest. A comparison between the annual means of nests on electricity poles with and without platforms did not reveal any significant differences in breeding success. However, closer examination of the nests transferred to platforms revealed a slight drop in chick productivity in the year following platform addition, which, however, became significantly higher in the subsequent year. Thus the transfer of nests to platforms appears to have only a short-term adverse effect and may be beneficial in the long run.