Sökning: "Bird migration"
Visar resultat 6 - 10 av 39 avhandlingar innehållade orden Bird migration.
6. On the role of migration for the distribution of arctic birds - a circumpolar perspective
Sammanfattning : Flexibility as well as constraints to the evolution of migration routes has the possibility of affecting large-scale patterns of geographical ranges of animals both by facilitating, but sometimes restricting, accessibility to and colonization of new regions. This dissertation concerns the broad-scale effects migration has on the distributional patterns of birds in the Arctic. LÄS MER
7. Differential migration in raptors
Sammanfattning : Differences between ages, sexes and populations in the timing of migration at Falsterbo, Sweden and in the choice of wintering site among raptors in Scania were investigated. Competition and dominance is the best primary explanation to the results. LÄS MER
8. Migratory routes and stopover behaviour in avian migration
Sammanfattning : Migratory birds, some small and light weight as matchboxes, engage in seasonal inter-continental journeys in order to take advantage of the long summer days and abundance of food at northern latitudes to breed and raise their young, and then escape the harsh winters by migrating to lower latitudes. This thesis deals with two important aspects of migration, the routes taken during migration and the birds’ behaviour at stopovers. LÄS MER
9. Adaptive flexibility in migratory behaviour of shorebirds
Sammanfattning : The phenomenon of bird migration has long fascinated us humans and it has prompted questions like where do they go or come from and how do they find their way? Arctic shorebirds are well known for their spectacular long-distance migrations with some species travelling more than 10 000 km every spring and autumn, and some even cover this distance in one single nonstop flight. The aim of my thesis was to investigate the flexibility of Arctic shorebirds when it comes to orientation behaviour, departure behaviour and migration strategy. LÄS MER
10. Climate change effects on migratory birds and on the ecology and behaviour of the willow warbler (Phylloscopus trochilus)
Sammanfattning : Recent global climate change is influencing the behaviour and ecology of species worldwide. Birds are typical systems to study in this context, as they are often migratory and thus subjected to a variety of environmental effects. LÄS MER
