Search for dissertations about: "Nocturnal migration"

Showing result 1 - 5 of 10 swedish dissertations containing the words Nocturnal migration.

2. 1. 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

4. 2. 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

5. 3. Migratory routes and stopover behaviour in avian migration

   Author : Robert Stach; Cecilia Kullberg; Sven Jakobsson; Thord Fransson; Åke Lindström; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Bird migration; migration routes; stopover; geolocator; radio telemetry; tracking; fuel deposition; etologi; Ethology;

   Abstract : 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. READ MORE

6. 4. Migration in anadromous brown trout

   Author : David Aldvén; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Downstream migration; Temperature; Discharge; Genetics; Growth rate; Climate change; Salmo trutta; Salmo salar; Sea trout; Salmon; Biology; Ecology;

   Abstract : This thesis investigates the anadromous migration of brown trout (Salmo trutta) with the overall aim to improve stock management within the region. Several field studies were conducted in different streams and coastal areas on the west coast of Sweden specifically aimed to evaluate environmental triggers for migration (Paper I), migration pathways and strategies (Paper III and IV) as well as the genetic differentiation of anadromous populations of brown trout (Paper V). READ MORE

7. 5. Individual consistency in bird migration

   Author : YANNIS VARDANIS; Evolutionär ekologi; []
   Keywords : bird migration; telemetry; bird ringing; individual consistency; repeatability; site fidelity; routes; timing; annual cycle; meta-analysis;

   Abstract : Slight differences, which appear in the individual animals of the same species and population have been recognised and appreciated ever since Darwin. These consistent intra-specific differences in animals have been considered very important because they are often inherited, and thus, provide the basic material for evolution to act on. READ MORE