Sökning: "migratory birds"

Visar resultat 16 - 20 av 43 avhandlingar innehållade orden migratory birds.

  1. 16. Magnetic map sense in animals: effects of geographic and magnetic displacements

    Författare :Jannika Boström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Oenanthe oenanthe; skylight polarization; geomagnetic map; geomagnetic field; endogenous migration programme; migratory fuelling; orientation; animal navigation;

    Sammanfattning : Migration research is a large and diverse field and in my thesis I have focused on the impact of geomagnetic cues on animal orientation, navigation and migratory fuelling. Several animal species from widely different taxa possess the ability to sense and make use of geomagnetic information during migratory or homing events. LÄS MER

  3. 17. Flight strategies in migrating birds: when and how to fly

    Författare :Martin Green; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geese; waders; terns; Animal ecology; Djurekologi; wind tunnel; radio telemetry; satellite telemetry; radar; formation flight; flight speed adjustment; wind drift; energy savings; departure decisions; bird migration; wind;

    Sammanfattning : Wind has a profound influence on migrating birds since it inevitably will influence travel time and energy expenditure. In this thesis I investigate how migrating birds are affected by, and use winds. LÄS MER

  4. 18. Viruses on the wing : evolution and dynamics of influenza A virus in the Mallard reservoir

    Författare :Michelle Wille; Jonas Waldenström; Timm Harder; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Co-infections; Ecology; Epidemiology; Evolution; Host-Parasite Interactions; Immunity; Influenza A Virus; Mallard; Phylogeny; Virology; Waterfowl; Wild Birds; Wildlife Disease; Zoonotisk ekologi; Zoonotic Ecology;

    Sammanfattning : This thesis explores the evolution of avian influenza A viruses (IAV), as well as host-pathogen interactions between these viruses and their main reservoir host, the Mallard (Anas platyrhynchos). IAV is a genetically diverse, multi-host virus and wild birds, particularly dabbling ducks, are the natural reservoir. LÄS MER

  5. 19. Stopover Ecology of Mallards : Where, when and how to do what?

    Författare :Daniel Bengtsson; Jonas Waldenström; W. Michael Eichholtz; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Age characters; body condition; departure decision; effects of influenza A virus; habitat selection; mallard; movement; Ottenby Bird Observatory; stopover ecology; weather; wild birds; Ecology; Ekologi;

    Sammanfattning : The mallard (Anas platyrhynchos) is the most numerous and widespread duck in the northern hemisphere and a model species in ecology and harvest management. Migration is a crucial life stage for many birds and understanding the drivers of migration has important implications for conservation biology and assessment of animal population responses to global changes. LÄS MER

  7. 20. On the importance of farmland as stopover habitat for migrating birds

    Författare :Juliana Dänhardt; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; conservation; bird migration; agriculture; stopover ecology; Golden plover; Pluvialis apricaria; landscape heterogeneity; organic farming; food availability; earthworms;

    Sammanfattning : Agricultural intensification has led to dramatic population declines among many farmland bird species. Negative effects of intensive farming in terms of decreased local habitat quality or structural simplification of farmland landscapes have reduced both reproductive outcome and winter survival of many species. LÄS MER