Sökning: "piscivory"

Hittade 4 avhandlingar innehållade ordet piscivory.

  1. 1. Foraging behaviour in piscivorous fish: mechanisms and patterns

    Författare :Håkan Turesson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; marine biology; Hydrobiology; piscivory; consumption rate; confusion effect; capture success; predation; encounter rate; prey choice;

    Sammanfattning : Mechanistic understanding of piscivore foraging at the individual level is important in order to understand and make predictions of piscivore effects at population and community levels. To understand the mechanisms affecting selection and consumption rates each step in the foraging cycle (search, encounter, active choice, attack, capture, ingestion, digestion) should be studied. LÄS MER

  3. 2. Pikeivory: behavioural mechanisms in northern pike piscivory

    Författare :Anders Nilsson; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; northern pike; cannibalism; kleptoparasitism; predation; optimal foraging; Animal ecology; Djurekologi;

    Sammanfattning : Optimal foraging and prey preference in top predators may affect population and community dynamics and structure. Also, optimal foraging and prey preference may shift with prevailing conditions, and therefore create changes in the effect of predation. LÄS MER

  4. 3. Lake bathymetry as driver of salmonid population size structure and biomass

    Författare :Sven Norman; Pär Byström; Karin A. Nilsson; Jan Karlsson; Per-Arne Amundsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake bathymetry; habitat-specific resource production; ontogenetic niche shifts; size structure; Arctic char; brown trout; populationsbiologi; Population Biology; Limnology; limnologi; zooekologi; Animal Ecology;

    Sammanfattning : Most fish species undergo ontogenetic niche shifts from feeding on pelagic zooplankton, to larger benthic invertebrates and in some cases also to fish. These ontogenetic niche shifts have strong impact on the interactions within and between species, with effects on individual growth, population abundance and food web dynamics. LÄS MER

  5. 4. Evolutionary ecology of arctic char (Salvelinus alpinus (L.)) : Intra- and interspecific interactions in circumpolar populations

    Författare :Johan Hammar; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Arctic char; Salvelinus alpinus; biogeography; niche; life history; population ecology; intra- and interspecific interactions; cannibalism; competition; landlocked; marginal populations; species border; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines a suite of ecological and genetic mechanisms influencing the fundamental and realized niche borders of European and North American populations of the Arctic char (Salvelinus alpinus (L.)) species complex in allopatry as well as in sympatry with brown trout (Salmo trutta) or brook trout (Salvelinus fontinalis). LÄS MER