© Steffen Hahn
Phenology of migration – environmental factors and individual attributes
More than 2 billion passerines migrate from their European breeding grounds to their residence areas in sub-Saharan Africa. The bird’s behaviour and migratory pattern is shaped by the seasonal food availability en route and in the African residence areas, as well as by the short term weather conditions. The critical factors for a successful return to the breeding grounds are barely known for most species and populations of trans-Sahara migrants.
- What are the temporal and spatial patterns of migration and residency for trans-Sahara migrants during the non-breeding period?
- What is the influence of seasonality of environmental factors on these patterns and their variability?
- How much are environmental factors in the African residence areas responsible for reproductive success?
- Are populations with high connectivity between breeding and non-breeding ranges more affected by local environmental conditions in the African residence area than those with low connectivity?
For selected populations, their African residence areas and to some extent their migratory routes and stopover sites are identified by using miniaturized geolocator . This allows investigating the impact of environmental conditions on the timing and spatial patterns during the non-breeding period. In addition, it enables the investigation of habitat use.
Comparing the relationship between environmental factors en route and the African residence areas with the breeding success will allow extracting the most relevant factors governing species- and population-specific migratory strategies. In addition, looking at kinship will shed light on the pheno- and genotypic variability in migratory patterns.
These questions are being investigated in hoopoes, Alpine swifts and wheatears. Several other species are similarly studied in cooperation with international partners.
The degree of flexibility in migratory patterns in relation to environmental conditions allows for estimating the potential and the limits of phenotypic plasticity, and thus the potential capacity to adapt to fast environmental changes, which can affect reproduction.
To learn more about these dynamic processes is fundamental for our understanding of bird migration, but can also be crucial for species-specific conservation measures.
- Quantification of the number of individuals migrating from Europe to sub-Saharan Africa.
- Denomination of African non-breeding residence areas for populations of hoopoes, Alpine swifts, barn swallows and nightingales.
- Confirmation of non-stop flights of Alpine swifts during their stay in sub-Saharan Africa.
Franz Bairlein, Institut für Vogelforschung "Vogelwarte Helgoland", Wilhelmshaven (wheatear)
Martin Schulze, NABU Sachsen-Anhalt Regionalverband Merseburg-Querfurt (European bee-eater)
José A. Alves, Universität Aveiro, Portugal (Bienenfresser)
Peter Adamík, Palacký Universität Olomouc, Tschechische Republik (Halsnbandschnäpper, Blaukehlchen)
Petr Procházka, Institut für Wirbeltier-Biologie; Tschechische Republik (Drossel- und Teichrohrsänger)
Schweizerischer Nationalfonds (SNF, Hoopoe)
Wolfermann-Nägeli Stiftung (Alpine Swift)
Rosmarie und Armin Däster-Schild Stiftung (Alpine Swift)
Stiftung Accentus (Hoopoe)
Linking events throughout the annual cycle in a migratory bird?non-breeding period buffers accumulation of carry-over effects.
Loop migration, induced by seasonally different flyway use, in Northern European Barn Swallows.
Cold spell en route delays spring arrival and decreases apparent survival in a long?distance migratory songbird
Dependencies in the timing of activities weaken over the annual cycle in a long-distance migratory bird.
Timing is crucial for consequences of migratory connectivity.
Breeding latitude leads to different temporal but not spatial organization of the annual cycle in a long-distance migrant.
Shifts in vegetation phenology along flyways entail varying risks of mistiming in a migratory songbird.
Repeatability of individual migration routes, wintering sites, and timing in a long-distance migrant bird.
Timing of migration and residence areas during the non-breeding period of barn swallows Hirundo rustica in relation to sex and population.
Directional shifts in migration pattern of rollers (Coracias garrulus) from a western European population.
Individual migration timing of common nightingales is tuned with vegetation and prey phenology at breeding sites.
Variable detours in long-distance migration across ecological barriers and their relation to habitat availability at ground.
Strong migratory connectivity and seasonally shifting isotopic niches in geographically separated populations of a long-distance migrating songbird.
First evidence of a 200-day non-stop flight in a bird.
Short-distance migration of Wrynecks Jynx torquilla from Central European populations.
Year-Round tracking of small Trans-Saharan migrants using light-level geolocators.
The natural link between Europe and Africa - 2.1 billion birds on migration.