Distribution and habitat selection of the Common Scoter Melanitta nigra in the eastern German North Sea
Understanding the processes affecting the distribution of an avian (and every other) species in time and space necessitates the inclusion of a variety of factors. Choice and utilisation of a habitat should be seen in the context of energetic costs and benefits, as organisms are believed to distribut...
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| Format: | Thesis |
| Language: | English |
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2020
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| Online Access: | https://oceanrep.geomar.de/id/eprint/59774/ https://oceanrep.geomar.de/id/eprint/59774/1/Diss_Kottsieper.pdf https://macau.uni-kiel.de/receive/macau_mods_00001086 |
| Summary: | Understanding the processes affecting the distribution of an avian (and every other) species in time and space necessitates the inclusion of a variety of factors. Choice and utilisation of a habitat should be seen in the context of energetic costs and benefits, as organisms are believed to distribute in order to enhance their survival. In this thesis, the distribution and habitat selection of the Common Scoter Melanitta nigra (Linneaus, 1758) a benthic-feeding sea duck spending much of its non-breeding season in the eastern German Bight, southeastern North Sea, was investigated with regard to seasonal differences. As Common Scoters are located in German Waters predominantly during their moulting and wintering season and as these periods reflect different energetic needs, this seasonal variability is expected to have an influence on how they distribute themselves relative to their food and disturbance. To analyse distribution patterns and habitat selection, Common Scoter count data from Seabirds at Sea surveys collected in 2006-2017 were used, either from a long term data base (FTZ) or obtained from additional surveys conducted during the PhD. To relate bird distributions to their prey base, benthos and sediment samples were collected in separate moulting and wintering areas to investigate benthic community structures. In addition to sediment samples, information on supplementary environmental parameters (such as water depth or bed shear stress) was gathered during surveys or taken from the literature. To determine, which parameter(s) might have the greatest influence on Scoter distribution, Generalised Additive Models (GAMs) with Integrated Nested Laplace Approximation (INLA) were performed for the moulting and wintering season. |
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