Abstract
Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans-Saharan migrants than autumn migration. Information about the behavior and interactions of migrants during the nonbreeding season in sub-Saharan Africa is also scarce for many species. Furthermore, very little is known about intra-African migration.
This thesis summarizes my research on the autumn migration of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I investigated the relationship between the timing of autumn migration and climatic variations at local and spatial scale.
The first three papers focused on speciesspecific analysis. In them I described the age-specific patterns in biometrics, phenology and migration strategies as well as trends in the population of the species. The papers show that adult and juvenile birds can use different migration strategies depending on time of season and prevailing conditions. Also, the fuel loads of some individuals were theoretically sufficient for a direct flight to important goal area, but whether they do so is still unknown.
The fourth paper and one manuscript investigate the behavior of garden warblers Sylvia borin, during the non-breeding season in Nigeria. The first paper shows that the species also utilizes habitats south of the savannah region, presumably on its way to the final goal area. Individuals also molt their flight feathers at this location and intraspecific interactions are non-aggressive.
The second manuscript investigates whether variations in the timing of migration of wader species at a stopover site in southeast Sweden is influence by local or regional climatic variables. The manuscript reveals that both factors may be important and that species breeding close to Ottenby and those breeding in the arctic may be affected by either of the two variables. In addition, breeding success is probably an important factor influencing timing of migration.
The third manuscript compares the breeding possibilities between two related cuckoo species using home range estimates derived from satellite telemetry data. The influence host species availability, foraging habitats are discussed.
This thesis summarizes my research on the autumn migration of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I investigated the relationship between the timing of autumn migration and climatic variations at local and spatial scale.
The first three papers focused on speciesspecific analysis. In them I described the age-specific patterns in biometrics, phenology and migration strategies as well as trends in the population of the species. The papers show that adult and juvenile birds can use different migration strategies depending on time of season and prevailing conditions. Also, the fuel loads of some individuals were theoretically sufficient for a direct flight to important goal area, but whether they do so is still unknown.
The fourth paper and one manuscript investigate the behavior of garden warblers Sylvia borin, during the non-breeding season in Nigeria. The first paper shows that the species also utilizes habitats south of the savannah region, presumably on its way to the final goal area. Individuals also molt their flight feathers at this location and intraspecific interactions are non-aggressive.
The second manuscript investigates whether variations in the timing of migration of wader species at a stopover site in southeast Sweden is influence by local or regional climatic variables. The manuscript reveals that both factors may be important and that species breeding close to Ottenby and those breeding in the arctic may be affected by either of the two variables. In addition, breeding success is probably an important factor influencing timing of migration.
The third manuscript compares the breeding possibilities between two related cuckoo species using home range estimates derived from satellite telemetry data. The influence host species availability, foraging habitats are discussed.
| Originalsprog | Engelsk |
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| Forlag | Natural History Museum of Denmark, Faculty of Science, University of Copenhagen |
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| Antal sider | 120 |
| Status | Udgivet - 2013 |