Search for dissertations about: "Raptors"

Showing result 6 - 10 of 10 swedish dissertations containing the word Raptors.

  2. 6. Predator-prey interactions of raptors in an arctic environment

    Author : Jesper Nyström; Anders Angerbjörn; A. Rolf Ims; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology of raptors; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Abstract : This thesis concerns the predator-prey interactions of three raptor species in a Swedish arctic community: the gyrfalcon (Falco rusticolus), the rough-legged buzzard (Buteo lagopus) and the golden eagle (Aquila chrysaetos). The gyrfalcon behaved like a highly specialised ptarmigan (Lagopus spp.) predator. READ MORE

  4. 7. Plumage Colours and the Eye of the Beholder : The Ecology of Colour and its Perception in Birds

    Author : Olle Håstad; Mats Björklund; Innes Cuthill; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; ultraviolet; colour vision; opsin; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Abstract : Virtually all diurnal birds have tetrachomatic vision based on four different colour receptors. As a result, birds are potentially able to perceive their environment in twice as many colours as humans and four times as many colours compared to most other mammals, which are dichromatic. READ MORE

  5. 8. Predators in low arctic tundra and their impact on community structure and dynamics

    Author : Maano Aunapuu; Tarja Oksanen; Ola Atlegrim; Oswald J. Schmitz; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; arthropods; coexistence; community dynamics; competition; food webs; hypothesis of exploitation ecosystems; intraguild predation; small mustelids; trophic cascades; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zooekologi; Animal Ecology;

    Abstract : The abundance of predators and their impact on ecosystem dynamics is a vividly discussed topic in current ecology. In my studies, incorporating field observations, field experiments and theoretical modeling, I explored the importance of predators and predation in a low arctic tundra ecosystem in northern Norway. READ MORE

  6. 9. Birds in the Flow: Flight Mechanics, Wake Dynamics and Flight Performance

    Author : Mikael Rosén; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Djurekologi; Animal ecology; Eleonora s falcon.; hunting; optimum wingspan; tail posture; wingbeat kinematics; wake topology; DPIV; flight performance; wake dynamics; flight mechanics; wind tunnel; Flight; bird;

    Abstract : I share my fascination of bird flight with many others, and here I summarise my thesis on the subject. This thesis emphasises the mechanics of bird flight by focusing on flight mechanics, wake dynamics and flight performance. READ MORE

  7. 10. Predation and shorebirds: predation management, habitat effects and public opinions

    Author : Daniel Isaksson; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Conservation; waders; predation; coastal pastures; redshank; lapwing; attitudes; human dimensions;

    Abstract : Many shorebird populations are rapidly declining and a high nest predation rate is one of the threats facing these populations. Thus, factors that affect predation and how to manage it in an effective way are receiving increased attention. READ MORE