Rogerson, Kate (2019) Storks on the move: the influence of anthropogenic food subsidies on the migration and movement behaviour of white storks, Ciconia ciconia. Doctoral thesis, University of East Anglia.
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Abstract
Migratory bird populations often comprise individuals that undertake a range of differing migratory journeys; environmental conditions and social cues can cause variation in migratory behaviour. The mortality risks for migratory birds also vary depending on their journeys, access to social cues and resources that are encountered. Over millennia human activities have influenced resource availability at the landscape level, for example farming practices, organic waste and, in recent decades, garden bird feeders, all provide predictable food subsidies that can affect the demography, survival and movement behaviour of the wildlife species that feed on them, including migratory birds.
This thesis investigates how use of anthropogenic food subsidies influences migratory behaviour and mortality of white storks (Ciconia ciconia). White storks have recently become partially migratory in Southern Europe and this has been associated with their year-round use of landfill sites for foraging. I will also explore if associations and social cues from family members influence juvenile migratory behaviour and use of new anthropogenic food subsidies. Recent advances in tracking technology allowed me to track storks with GPS/GSM devices and to study in-depth their daily movements in order to understand use of anthropogenic food subsidies and associations between individuals, as well as their large-scale movements such as trans-continent migration.
The study findings indicate that greater use of landfill sites is associated with lower mortality rates for juvenile white storks. In addition juveniles that spend more time at landfill sites prior to migration delay the onset of migration, while juveniles that visit landfill sites more on migration have slower migrations, taking more days with slower speeds. Juvenile use of landfill sites and their migratory behaviour is independent of their family members. The impending closure of landfill sites across the EU may therefore have negative implications for white stork demography and may alter migratory behaviour for migratory populations.
Item Type: | Thesis (Doctoral) |
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Faculty \ School: | Faculty of Science > School of Environmental Sciences |
Depositing User: | Chris White |
Date Deposited: | 14 Apr 2021 13:00 |
Last Modified: | 14 Apr 2021 13:00 |
URI: | https://ueaeprints.uea.ac.uk/id/eprint/79749 |
DOI: |
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