Search for dissertations about: "Passerines"

Showing result 1 - 5 of 19 swedish dissertations containing the word Passerines.

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. Metals take flight : Transport and effects across ecosystems

   Author : Johan Lidman; A. M. M. Berglund; Micael Jonsson; Christian Bigler; Brendan Mckie; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Metals; aquatic subsidies; passerines; aquatic insects; environmental science; miljövetenskap; ekotoxikologi; Ecotoxicology;

   Abstract : Metal contamination can have severe toxic effects in the ecosystems, resulting in loss of biodiversity, reduced abundance of organisms, and loss of ecosystem services. Traditionally, aquatic ecosystems have been regarded as a sink of metal contamination. READ MORE

5. 3. Fattening strategies in wintering passerines

   Author : Kristjan Lilliendahl; Innes C Cathill; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; Biologi; zoologisk ekologi; Animal Ecology;

   Abstract : Stored fat is a main source of energy for birds in winter and it seems reasonable that fatter birds should survive better. Small birds wintering at high latitudes, however, carry less fat than their capacity permits, suggesting a predation cost of excessive fatness. READ MORE

6. 4. Stopover behaviour in migratory songbirds: timing, orientation and departures

   Author : Sissel Sjöberg; Funktionell zoologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; flight duration; orientation; departure timing; stopover behaviour; stopover duration; flight behaviour; reverse migration; route choice; compass calibration; passerines; Bird migration;

   Abstract : Songbird migrants use stopovers between flight bouts to rest and refuel for the upcoming flights. Behaviours affecting where, when and how long to stay at stopover sites will affect how successful the overall migration will be, which has significant consequences for the overall fitness and mortality of the birds. READ MORE

7. 5. Effects of created habitats on farmland biodiversity

   Author : Annelie Jönsson; Biodiversitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; agricultural intensification; brown hare; common pheasant; farming intensity; granivorous passerines; grey partridge; habitat creation; landscape heterogeneity; pollinators;

   Abstract : Agricultural intensification has caused severe declines among biodiversity in European farmland over the last half century. The transformation of the agricultural landscape has led to reduced availability of key resources such as food, nesting habitat and shelter. READ MORE