Factors affecting population size of Baltic Common Eiders Somateria ...

In recent decades, the Baltic-Wadden Sea fl yway population of Eiders has
undergone marked changes, fi 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 insuffi cient on their own to explain the overall level of decline.
The present thesis describes the overall population development in
the Baltic-Wadden Sea fl 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 relation to
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 measures that may be
introduced and which might help in restoring the unfavourable development
of the Baltic Eider populations.
National Environmental Research Institute ISBN 978-87-7073-040-2
University of Aarhus . Denmark
Factors affecting population size of Baltic Common Eiders Somateria mollissima