Sökning: "visual ecology"

Visar resultat 6 - 10 av 46 avhandlingar innehållade orden visual ecology.

  1. 6. Evolutionary Ecology of Floral Traits in Fragrant Orchids

    Författare :Elodie Chapurlat; Nina Sletvold; Jon Ågren; Magne Friberg; Kathleen Kay; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; agents of selection; diurnal and nocturnal pollination; divergent selection; field experiment; floral evolution; floral scent; Gymnadenia conopsea; Gymnadenia densiflora; Orchidaceae; phenotypic selection; pollinator-mediated selection; spatial variation; scent rhythm;

    Sammanfattning : Why are flowers so diverse? Much of floral evolution is thought to be driven by pollinator-mediated selection. However, the connection between macroevolutionary patterns of floral diversity and microevolutionary processes remains poorly understood. In this thesis, I have used the fragrant orchids Gymnadenia conopsea s.s. LÄS MER

  3. 7. 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

  4. 8. Causes and consequences of niche differentiation between color morphs of pygmy grasshoppers

    Författare :Einat Karpestam; Anders Forsman; Birgitta Tullberg; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; color polymorphism; visual predators; Tetrix subulata; differential habitat use; niche; thermoregulation; feeding preferences; stable isotopes; Evolutionary Biology; Evolutionsbiologi;

    Sammanfattning : In this thesis, I used the color polymorphic pygmy grasshopper, Tetrix subulata, as a model system in order to investigate the degree of niche differentiation between alternative color morphs that are present within a single population. First, I hypothesized that individuals belonging to different color morphs differ in their innate food preference due to somewhat dissimilar physiology, and in their actual food consumption due in part to differential habitat use. LÄS MER

  5. 9. Trophic interactions and behaviour : Studies relevant to a Baltic Sea biomanipulation

    Författare :Per B. Holliland; Sture Hansson; Elena Gorokhova; Peter Tiselius; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; zooplankton; non-indigenous species; selectivity; food web; rearing environment; fish stocking; Sander lucioperca; diel vertical migration; ontogeny; ovigerous; Marine Ecology; marin ekologi;

    Sammanfattning : The main theme of this thesis is the interactions of animals with the environment and each other. The thesis was written within the framework of a biomanipulation project “Pikeperch in Himmerfjärden”. LÄS MER

  7. 10. Living in a predation matrix : Studies on fish and their prey in a Baltic Sea coastal area

    Författare :Ida Ahlbeck; Sture Hansson; Hannu Lehtonen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diet analysis methods; Sander lucioperca; behaviour; rearing environment; diel vertical migration; Acartia spp.; Eurytemora affinis; Perca fluviatilis; stable isotopes; body condition; sedentarity; Marine Ecology; marin ekologi;

    Sammanfattning : This thesis was written within the framework of a biomanipulation project where young-of-the-year (YOY) pikeperch (Sander lucioperca) were stocked to a Baltic Sea bay to improve water quality through a top-down trophic cascade. The aim of my doctorial studies was however focused on a broader ecological question, namely predation (the main driving force in a biomanipulation). LÄS MER