Search for dissertations about: "birds migration"

Showing result 1 - 5 of 50 swedish dissertations containing the words birds migration.

2. 1. Ecology and evolution of large-scale bird migration patterns : A natural history and comparative study of the migration in common and little ringed plovers

   Author : Linus Hedh; Evolutionär ekologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ringed plover; leap-frog migration; migration speed; migration process; light level geolocator; migration;

   Abstract : Migration distance and seasonal redistribution patterns may vary between and within bird populations. A common pattern is leap-frog migration, in which northerly breeding populations migrate farther and winter south of more southerly breeding populations. READ MORE

4. 2. Flight Behaviour of Passerines on Nocturnal Migration

   Author : Cecilia Nilsson; Evolutionär ekologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Bird migration; Passerines; Flight Behaviour; Tracking radar; Optimal migration; Flight speed; Airspeed; Wind drift; Nocturnal migration; Coastline effects; Flight directions; Reverse migration;

   Abstract : Many passerines migrate during the night and at high altitudes, making their migration difficult to observe. By using tracking radars we have been able to make exact observations of the flight behaviour of passerines on nocturnal migration, which has enabled us to test several hypotheses about adaptive values and constraints regarding migratory behaviour in different ecological contexts. READ MORE

5. 3. On the role of migration for the distribution of arctic birds - a circumpolar perspective

   Author : Sara Henningsson; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; bird migration; broad-scale distributions; geographic breeding range; geography of migration; non-breeding range; barriers to migration; Arctic birds; evolution of migration routes;

   Abstract : 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. READ MORE

6. 4. There and Back Again - nocturnal migratory behaviour of birds during spring and autumn

   Author : Håkan Karlsson; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; migration; seasons; flight; orientation; navigation; behaviour; strategies; birds; nocturnal;

   Abstract : This dissertation explores the migratory behaviour of nocturnally migrating passerines and common swifts (Apus apus). Birds passing Lund (southern Sweden) and Abisko (northernmost Scandinavia) where sampled using tracking radar. The aim has been to investigate potential diverging strategies between spring and autumn migration. READ MORE

7. 5. Magnetic orientation in migratory birds

   Author : Rachel Muheim; Funktionell zoologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Animal ecology; Djurekologi; cue-conflict; clock-shift; cue calibration; geomagnetic field; high Arctic latitudes; Emlen funnel; magnetic compass; magnetoreception; navigation; migration; bird; orientation;

   Abstract : My thesis focuses on magnetic orientation in migratory birds, i.e. how they can perceive information from the Earth’s magnetic field and use it for orientation. READ MORE