Sökning: "animal flight"

Visar resultat 11 - 15 av 25 avhandlingar innehållade orden animal flight.

  1. 11. Across landscapes and seascapes : The movement ecology of diving and flying guillemots and gulls during breeding

    Författare :Thomas J. Evans; Evolutionär ekologi; []
    Nyckelord :Uria aalge; Larus fuscus; Laridae; animal flight; foraging ecology; movement ecology; seabirds;

    Sammanfattning : Most seabirds breed colonially, at which time they make central-place foraging trips. Parents must collect food both for themselves and for egg production/chick-rearing. LÄS MER

  3. 12. Rarity in boreal stream: patterns, causes and consequences

    Författare :Per-Ola Hoffsten; Bo W. Svensson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Central Sweden; site occupancy; dispersal limitation; natural disturbances; recolonization; flight-morphology; metapopulation; habitat stability; spring specialists; Crunoecia irrorata; niche limitation; Isogenus nubecula; nestedness; longitudinal distribution; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zooekologi; Animal Ecology;

    Sammanfattning : Patterns of site occupancy among boreal stream insects were studied in central Sweden with focus on sparsely distributed species and the role of dispersal and niche limitations.In the study of dispersal limitation, I found that effects of an extraordinarily harsh winter in small to medium-sized streams were strongest in sites located in small streams and far from lake outlets. LÄS MER

  4. 13. The visual ecology of bees - Tales of diverse eyes and behaviours

    Författare :Pierre Tichit; Funktionell zoologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal behaviour; Arthropods; Bumblebees; Compound Eyes; Crystalline cones; Flight control; Image analysis; Landing; Sensory ecology; Stingless bees; Vision; X-ray microtomography;

    Sammanfattning : The buzzing flight of bees is a popular summer hit. Yet, outside of a few familiar species of honeybees and bumblebees, these fantastic little creatures are still mostly unknown. With about twenty-five thousand species, bees are a very diverse group. They can be found in drastically different habitats. LÄS MER

  5. 14. 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

  7. 15. The evolution of territoriality in butterflies

    Författare :Martin Bergman; Christer Wiklund; Ronald Rutowski; Stockholms universitet; []
    Nyckelord :territoriality; Lepidoptera; sexual selection; mating success; mate locating behaviour; resource-holding potential; motivation; courtship solicitation; NATURAL SCIENCES; NATURVETENSKAP; zoologisk ekologi; Animal Ecology;

    Sammanfattning : Competition over mating opportunities is a conspicuous characteristic of animal behaviour. In many butterfly species the males establish territories in places advantageous for encountering females. This thesis addresses questions about how territoriality has evolved and is maintained in butterflies. LÄS MER