Sökning: "predator regime"

Hittade 4 avhandlingar innehållade orden predator regime.

  1. 1. The prey perspective - behaviour and appearance in a world of predators

    Författare :Johan Ahlgren; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Local adaptation; predator regime; phenotypic plasticity; inducible defence; mortality; animal personality; predator; trait-compensation;

    Sammanfattning : The varieties of prey phenotypes that have been revealed in nature are vast and many of these phenotypes are the result of the selective force that predators have had on prey traits in the past. Even within species and populations we see variations due to both differences in the selection forces they live under but also due to individual trait variation. LÄS MER

  2. 2. Local adaptive pigmentation in Asellus aquaticus -effects of UV-radiation and predation regime

    Författare :Jonas Johansson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; damselfly; perch; UV-avoidance; isopod; anti-predator traits; evolution; selective predation; limnologi; akvatisk ekologi; Animal ecology; Djurekologi;

    Sammanfattning : Pigmentation in the freshwater isopod Asellus aquaticus differed between two habitats. Asellus were lighter pigmented in stands of submerged stonewort vegetation, than in nearby reed stands. Moreover, Asellus pigmentation became lighter with time in recently established stonewort stands. LÄS MER

  3. 3. Effects of abiotic and biotic factors on hatching, emergence and survival in Baltic salmon (Salmo salar L.)

    Författare :Eva Brännäs; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Baltic salmon; salmo salar; eggs; egg colour; alevins; fry; photoperiod; temperature; hatching; emergence pattern; synchronization; survival;

    Sammanfattning : This thesis deals with important factors that affect the temporal organization of emergence and early survival of Baltic salmon (Salmo salar L.). The study population was obtained from the Norrfors hatchery (63°50'N,20°05'E), Umeälven (Ume river) in Northern Sweden. LÄS MER

  4. 4. Habitat selection, nest predation and conservation biology in a Black-tailed Godwit (Limosa limosa) population

    Författare :Tomas Johansson; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Black-tailed godwit; Limosa limosa; nest site selection; nest predation; philopatry; risk analysis; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

    Sammanfattning : This thesis focuses on a black-tailed godwit (Limosa limosa) population, consisting of 35-40 pairs, that breeds on a grazed shore meadow on SE Gotland, Sweden. The small size of the population makes it more prone to extinction due to chance events, than a larger population.The godwits showed microhabitat preferences when choosing nest sites. LÄS MER