Sökning: "bird"

Visar resultat 1 - 5 av 184 avhandlingar innehållade ordet bird.

  1. 1. Individual consistency in bird migration

    Författare :YANNIS VARDANIS; Evolutionär ekologi; []
    Nyckelord :bird migration; telemetry; bird ringing; individual consistency; repeatability; site fidelity; routes; timing; annual cycle; meta-analysis;

    Sammanfattning : Slight differences, which appear in the individual animals of the same species and population have been recognised and appreciated ever since Darwin. These consistent intra-specific differences in animals have been considered very important because they are often inherited, and thus, provide the basic material for evolution to act on. LÄS MER

  2. 2. Bird-parasite interactions : Using Sindbis virus as a model system

    Författare :Karin M. Lindström; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Carduelis chloris; Sindbis virus; host-parasite interaction; ornament; social dominance; testosterone; sexual selection; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

    Sammanfattning : This thesis focuses on the evolutionary interactions between birds and a parasite, the mosquito-borne Sindbis virus (Togaviridae, Alphavirus). In conclusion, the results show that the Sindbis virus is widespread among birds, and that the fitness of infected hosts may be reduced by the virus. LÄS MER

  3. 3. Climate change effects on migratory birds and on the ecology and behaviour of the willow warbler (Phylloscopus trochilus)

    Författare :Johanna Hedlund; Sven Jakobsson; Thord Fransson; Cecilia Kullberg; Sara Cousins; Martin Schaefer; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; climate change; bird migration; ecology; phenology; bird; avian; willow warbler; chaffinch; land use change; landscape ecology; historical ecology; etologi; Ethology;

    Sammanfattning : Recent global climate change is influencing the behaviour and ecology of species worldwide. Birds are typical systems to study in this context, as they are often migratory and thus subjected to a variety of environmental effects. LÄS MER

  4. 4. Feathers by day, membranes by night - Aerodynamic performance in bird and bat flight

    Författare :Florian Muijres; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; animal flight; aerodynamics; vortex wake; actuator disk; flight performance; span efficiency; bird; bat; wind tunnel; PIV; Pied Flycatcher; Glossophaga soricina; Leptonycteris yerbabuenae;

    Sammanfattning : The efficiency and performance of a flying animal is directly related to the aerodynamics around its body and flapping wings. Here, I have developed methods for quantifying the wake dynamics around a flying animal. The results are used to estimate the aerodynamic performance of flapping flight. LÄS MER

  5. 5. Bird Species in Urban and Agricultural Landscapes : Bird diversity patterns along an urbanisation gradient and crop damage caused by birds on the Deccan Plateau, India

    Författare :Manoj Ashokrao Kale; Prosun Bhattacharya; Gabor L. Lövei; Peter Kjellander; KTH; []
    Nyckelord :Bird assemblage structure; Forest-urban gradient; Scale-sensitive diversity; Crop depredation; Crop damage assessment; Deccan Plateau; India.; Mark- och vattenteknik; Land and Water Resources Engineering;

    Sammanfattning : The major human activities that have transformed the Earth include agriculture and urbanization. The present study was conducted to contribute to a description of the effect on birds of urbanization and agriculture in an Indian region. LÄS MER