Christensen, T. K. 2008. PhD thesis. Factors affecting population size of Baltic Common EidersSomateria mollissima. Department of Wildlife Ecology and Biodiversity, National Environmental Research Institute, University of Aarhus, Denmark and Department of Biology , University of Copenhagen. 204 pp

 

Summary

Inrecent decades, the Baltic-Wadden Sea ?yway population of Eiders has undergone marked changes, ?rst experiencing a steep increase during the 1970s and 1980s, followed by a marked decline during the 1990s. There have been several reported incidences involving mass simultaneous mortality amongst this population during the period of decline, each of which were insuf-?cient on their own to explain the overall level of decline.

 

The present thesis describes the overall population development in the Baltic-Wadden Sea ?yway population of Eiders. In relation to the recent population decline, the thesis addresses the occurrence of epidemic disease, parasite infestations and the implications of hunting in relationto population development. The concept of body condition is introduced as a common currency, because the role of body condition in relation to population trends has not often been discussed in the literature. Finally, the synopsis is used to discuss the potential conservation measuresthat may be introduced and which might help in restoring the unfavourable development of the Baltic Eider populations.

 

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