Sökning: "Animal Ecology"

Visar resultat 21 - 25 av 276 avhandlingar innehållade orden Animal Ecology.

  1. 21. Trade-offs between life history traits and immune defence in the collared flycatcher Ficedula albicollis

    Författare :Dag Nordling; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines the effects of reproductive effort on immune function and parasite resistance in breeding collared flycatchers, Ficedula albicollis. It also focuses on the role of the immune function in the trade-off between number and fitness of offspring. LÄS MER

  3. 22. Causes and consequences of quantitative trait variation for reproductive performance in hole nesting birds

    Författare :Robert Przybylo; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; timing of breeding; climate change; parental and territorial quality; morphology; sexual size dimorphism; intersexual niche differentiation; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines the causes and consequences of environmental variability and individual morphological differences on breeding success and survival in three hole nesting birds.An analysis of directional and stabilising natural selection in Collared Flycatchers (Ficedula albicollis) suggested that forces of selection acting on quantitative traits are weak and cannot explain the observed sexual size dimorphism (SSD) in this species. LÄS MER

  4. 23. Sexual selection in the collared flycatcher (Ficedula albicollis) : A life-history perspective

    Författare :Anna Qvarnström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Sexual selection; life-history; honest signalling; fighting ability; genotype-environment interaction; direct benefits; indirect benefits; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis integrates sexual selection theory with life history theory to elucidate the causes and consequences of variation in a male secondary sexual trait. The model organism, the collared flycatcher (Ficedula albicollis), was studied on Gotland, Sweden. LÄS MER

  5. 24. Mating behaviour and sexual selection in non-lekking fallow deer (Dama dama)

    Författare :David Stenström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Fallow deer; mating behaviour; sexual selection; scent marking; plasticity of behaviour; antler asymmetry; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines both behavioural and morphological traits influencing male mating success in non-lekking fallow deer (Dama dama). The thesis contains results based on behavioural observations and experimental studies made on Öland and around Uppsala, Sweden. LÄS MER

  7. 25. Female Reproductive Strategies in the Ruff (Philomachus pugnax)

    Författare :Katherine Thuman; Fredrik Widemo; Robert Montgommery; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : Traditionally, females have been considered to be strictly monogamous. Today, we know that females in the majority of species actively seek out and mate with several males. Trying to understand female preferences, including what benefits mate choice entails, has been the focus of intense research during the last decades. LÄS MER