Sökning: "prey choice"
Visar resultat 1 - 5 av 13 avhandlingar innehållade orden prey choice.
1. Foraging behaviour in piscivorous fish: mechanisms and patterns
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
2. Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective
Sammanfattning : Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. LÄS MER
3. On the origin of polymorphism - consequences of competition and predation in heterogeneous environments
Sammanfattning : In this thesis, I have studied when an initially monomorphic population can diverge into two morphs in a heterogeneous environment. Evolution is driven by competition for resources or predation. In Paper I, we studied source-sink dynamics during evolution in an environment with two types of resource of different abundance in two habitats. LÄS MER
4. Forest-stream linkages : Experimental studies of foraging and growth of brown trout (Salmo trutta L)
Sammanfattning : Riparian vegetation along streams and rivers affects the aquatic community in numerous ways and often operates as a link for energy flux between forest and streams. The studies presented in this licentiate thesis focus on light and terrestrial invertebrates, two factors influenced by riparian zone structure, which potentially affect stream ecosystems and thus also brown trout (Salmo trutta). LÄS MER
5. Predatory processes in Baltic benthos
Sammanfattning : The Baltic soft-bottom community is uniquely simple, with only a few benthic macro-faunal species, and is therefore well suited for mechanistic studies of inter-specific interactions. Two of the dominating organisms in this benthic community are the amphipod Monoporeia affinis and the bivalve Macoma balthica. Field surveys have shown that M. LÄS MER
