Sökning: "Ekologi: zoologi"

Visar resultat 1 - 5 av 78 avhandlingar innehållade orden Ekologi: zoologi.

  1. 1. Mechanistic aspects of host plant preference in butterflies

    Författare :Alexander Schäpers; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; zoologisk ekologi; Animal Ecology; etologi; Ethology; zoologi; Zoology;

    Sammanfattning : Searching and locating resources is essential for survival. In herbivorous insects search behavior is conducted on several scales, requiring input and integration of information from different sensory modalities. LÄS MER

  3. 2. Pine weevil feeding behaviour in relation to conifer plant properties

    Författare :Frauke Fedderwitz; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : The pine weevil (Hylobius abietis (L.)) is a forest insect distributed over the Palearctic region. The adults feed on the phloem of young conifer plants causing high economic losses for the European forest industry. Still, there is very little knowledge about the structure of its feeding behaviour. LÄS MER

  4. 3. Cycles of voles, predators, and alternative prey in boreal Sweden

    Författare :Birger Hörnfeldt; S. Erlinge; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; 3-4 year cycles; Clethrionomys glareolus; Clethrionomys rufocanus; Microtus agrestis; snap-trapping; rate of change; population regulation; delayed density-dependence; time-lag mechanism; seasonality; predation; food; predator avoidance; foraging behaviour; Aegolius funereus; nest boxes; numerical response; nomadism; Vulpes vulpes; Sarcoptes scabiei vulpes; Lepus timidus; Francisella tularensis; Tetraonidae; hunting statistics; zooekologi; Animal Ecology;

    Sammanfattning : Bank voles, grey-sided voles, and field voles had synchronous 3-4 year density cycles with variable amplitudes which averaged about 200-fold in each species. Cycles of vole predators (red fox and Tengmalm's owl), and their (foxes') alternative prey (mountain hare and forest grouse) lagged behind the vole cycles. LÄS MER

  5. 4. Wolverine ecology and conservation in the Western United States

    Författare :Robert Michael Inman; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Successful conservation of rare species requires an understanding of the niche, knowledge of the scale over which a viable population exists, and a system that provides adequate funding to take the necessary actions. I radio-marked wolverines in the Yellowstone Ecosystem and examined spatial ecology and reproductive chronology from an evolutionary perspective to better define the wolverine niche. LÄS MER

  7. 5. Variation in age and size at maturation in two benthic crustaceans in the Gulf of Bothnia

    Författare :Kjell Leonardsson; J. Ekman; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Age at maturation; alternative prey; Bergmanris rule; cannibalism; growth; life-history theory; mortality; Mvoxocephalus quadricornis; poikilotherm; Pontoporeia affinis; population dynamics; risk- taking behaviour; Saduria entomon; size at maturation; temperature;

    Sammanfattning : The thesis deals with variation in age and size at maturation in Saduria entomon and Pontoporeia affinis along a depth gradient in the Gulf of Bothnia, Sweden. I have analysed at what sizes and ages animals should mature in relation to growth and mortality conditions. LÄS MER