Sökning: "migration speed"

Visar resultat 1 - 5 av 45 avhandlingar innehållade orden migration speed.

1. 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

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

   Sammanfattning : 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. LÄS MER

3. 2. Flight Behaviour of Passerines on Nocturnal Migration

   Författare :Cecilia Nilsson; Evolutionär ekologi; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 3. Ecology of red admiral migration

   Författare :Oskar Brattström; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nymphalidae; Lepidoptera; migration patterns; migration; genetic structure; AFLP; lipid content; Inachis io; stable isotopes; orientation; navigation; weather; Animal ecology; red admiral; Vanessa atalanta; Djurekologi;

   Sammanfattning : The red admiral (Vanessa atalanta) is a migratory butterfly that can be found in North America, North Africa, Europe and some parts of Asia. In Europe the main part of the population spend winter in the Mediterranean region and the following spring leave this area to breed further to the north. LÄS MER

5. 4. On Specifying and Estimating Economic Growth as a Spatial Process : Convergence, Inequality, and Migration

   Författare :Martin E. Gustafsson; Roger Bivand; Uppsala universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Social and economic geography; Economic geography; economic growth; regional convergence; migration; spatial statistics; spatially correlated errors; geographical dependence; Kulturgeografi; Human geography; Kulturgeografi; kulturgeografi; Social and Economic Geography;

   Sammanfattning : This thesis includes three self-contained papers. The first paper considers the effect of geographically dependent observations on cross-sectional growth convergence and proposes a way of decomposing the level of technology taking into account geographical variation in growth rates. LÄS MER

7. 5. Adaptive flexibility in migratory behaviour of shorebirds

   Författare :Johanna Grönroos; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bird migration; compensation; departure decision; flight distance; migration speed; migration strategy; orientation; shorebird; stopover; wind drift; wind selectivity;

   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