Sökning: "bird"

Visar resultat 11 - 15 av 204 avhandlingar innehållade ordet bird.

  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

  3. 12. Dispersal, inbreeding and fitness in natural populations

    Författare :Bengt Hansson; MEMEG; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; immigration; inbreeding; inbreeding depression; heterozygosity; microsatellite; great reed warbler; bird; Djurekologi; Animal ecology; philopatry; heritability; founder event; dispersal; bottleneck;

    Sammanfattning : To evaluate how inbreeding affects the viability of small populations, it is crucial to determine what constitutes a population (i.e., the number of breeders in local patches and the degree of dispersal), and also to estimate the reproductive consequences of philopatry and emigration. LÄS MER

  4. 13. Wooded or treeless pastures? : Linking policy, farmers' decisions and biodiversity

    Författare :Simon Jakobsson; Regina Lindborg; Sara A O Cousins; Jan Plue; Tim Benton; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bat; biodiversity; bird; canopy cover; Common Agricultural Policy; European Union; farmer; functional diversity; germination; grassland; multi-taxa; pasture; plant; policy; seed sowing; tree density; trees; Physical Geography; naturgeografi;

    Sammanfattning : Worldwide, biodiversity conservation is one of the key challenges for a sustainable future of nature and society. It is particularly important to preserve high quality habitats within otherwise intensively managed agricultural landscapes. LÄS MER

  5. 14. 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

  7. 15. Evolutionary dynamics of migration and breeding in wild birds: genetic architecture, sexual conflicts and evolutionary constraints

    Författare :Maja Tarka; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantitative genetics; heritability; intralocus sexual conflict; antagonistic selection; QTL; G-matrix; wing length; arrival date; migration; geolocator; bird; Acrocephalus arundinaceus;

    Sammanfattning : Our knowledge of the evolutionary potential of traits involved in different selective episodes, especially in natural populations, is still limited. This is true for questions such as the genetic basis and inheritance of traits, how natural and sexual selection acts on them, and how selective conflicts influence the evolutionary response to selection. LÄS MER