Sökning: "Bird migration"

Visar resultat 11 - 15 av 39 avhandlingar innehållade orden Bird migration.

  1. 11. Tales of the flying earth: The effect of host flyways on the phylogeny of shorebird lice (Phthiraptera: Ischnocera)

    Författare :Daniel Gustafsson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Parasite; Bird; Lice; Louse; Migration; Evolution; Ecology; Co-evolution; Lunaceps; Shorebirds; Carduiceps; Quadraceps; Revision; Phylogeny; Saemundssonia; Rallicolidae; Charadriiformes; Scolopacidae; Phthiraptera; Philopteridae; Ischnocera; Sandpiper; Flyways; Chewing Lice;

    Sammanfattning : On the wings, bodies, and heads of most birds there are lice. These lice spend their whole lives on their host, with the exception of the few lice that get the opportunity to transfer from one host to another, typically when the hosts come into physical contact with each other. LÄS MER

  2. 12. Magnetic orientation in migratory birds

    Författare :Rachel Muheim; Funktionell zoologi; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 13. Genetic Variation and Migration of Waders

    Författare :Liv Wennerberg; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mtDNA sequencing; microsatellite analysis; Dunlin; Calidris alpina; Curlew Sandpiper; Calidris ferruginea; White-rumped Sandpiper; Calidris fuscicollis; carbon isotope ratios; Zoologi; Zoology; Ecology; bird migration; population genetics; Ekologi; Animal ecology; Djurekologi;

    Sammanfattning : The migratory behaviour of birds has received much scientific interest, though many questions still remain unsolved. One of the reasons for this is the difficulty of following the birds as they move between breeding and wintering localities. Populations may mix on migration and the origin of individual birds is difficult to assess. LÄS MER

  4. 14. Living in a Variable Environment : Reproductive Decisions in Wild Bird Populations

    Författare :Mårten B. Hjernquist; Lars Gustafsson; Marcel Visser; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; evolutionary ecology; competition; sex allocation; paternity; EPP; inadvertent social information; migration; breeding density; territory quality; territory availability; great tit; blue tit; Ficedula albicollis; Biology; Biologi; Animal Ecology; zooekologi;

    Sammanfattning : In nature, environments are often variable and heterogeneous influencing ecological and evolutionary processes. This thesis focus on how animals interact with their environment and how that affects the reproductive decisions they make. LÄS MER

  5. 15. Bird orientation: external cues and ecological factors

    Författare :Johan Bäckman; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tracking radar; Emlen funnel.; Animal ecology; Djurekologi; oscillatory orientation; roosting flight; scatter; concentration; heading; cue calibration; light dependent; magnetoreception; subcutaneous fat stores; body condition; energetics; geomagnetic field; visual cues; orientation; birds; migration;

    Sammanfattning : Birds are generally capable of accurate orientation. In this thesis I present studies about the external cues and the ecological factors that influences bird orientation. A multitude of environmental cues are used to select and maintain a proper direction. LÄS MER