Sökning: "Predation"

Visar resultat 1 - 5 av 235 avhandlingar innehållade ordet Predation.

  1. 1. Why and how brain size evolves : Sociality, predation and allometry

    Författare :Wouter van der Bijl; Niclas Kolm; Joah Madden; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; brain size; brain size evolution; encephalization; predation; predator inspection; sociality; animal contest; constraint; etologi; Ethology;

    Sammanfattning : The evolution of the vertebrate brain has remained a topic of intense interest from biologists over many decades. Evolutionary biologists have seen it as an intriguing example of how the size and structure of a trait evolves across large phylogenies and under body size constraints, with both large shifts in deep evolutionary time and continuous smaller scale adaptation. LÄS MER

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

    Författare :Daniel Isaksson; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :Conservation; waders; predation; coastal pastures; redshank; lapwing; attitudes; human dimensions;

    Sammanfattning : 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. LÄS MER

  3. 3. The aquatic microbial food web and occurence of predation-resistant and potentially pathogenic bacteria, such as Francisella tularensis

    Författare :Johanna Thelaus; Agneta Andersson; Mats Forsman; Farooq Azam; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; bacteria; protozoa; ecology; predation; nutrient-availability; microbial food web; model; predation-resistance; Francisella; reservoir; biofilm formation; Freshwater ecology; Limnisk ekologi;

    Sammanfattning : All natural aquatic systems harbour a vast variety of microorganisms. In the aquatic microbial food web, the larger microorganisms (i.e. protozoa) feed on the smaller microorganisms (i. LÄS MER

  4. 4. The importance of predation in benthic stream communities

    Författare :Jonas Dahl; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Ekologi; Ecology; invertebrate predators; vertebrate predators; Predation; streams;

    Sammanfattning : There has been considerable debate whether or not predators has any significant effects on prey densities in streams. This thesis examines the importance of predation in stream communities. I have conducted both field and laboratory studies where I have studied how both vertebrate and invertebrate predators affects benthic prey. LÄS MER

  5. 5. Mechanisms structuring the pelagic microbial food web : Importance of resource and predation

    Författare :Kristina Samuelsson; Agneta Andersson; Christiane Lancelot; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Ecology; pelagic microbial food web; bacteria; flagellates; ciliates; phytoplankton; mixotrophy; nutrient status; predation limitation; resource limitation; Baltic Sea; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : Temporal and spatial variations of pelagic microorganisms in the northern Baltic Sea were studied, as well as factors influencing their abundance and growth rates. Three main questions were asked 1) How does increased productivity influence the structure of the microbial food web? 2) Does predation limitation vary between trophic levels? 3) What is the relative importance of resource and predation limitation at different trophic levels?A field study in the northern Baltic Sea showed that dominating protozoa, flagellates and ciliates, increased with increasing primary productivity from north to south. LÄS MER