Sökning: "Female reproductive success"

Visar resultat 21 - 25 av 51 avhandlingar innehållade orden Female reproductive success.

  1. 21. Reproductive Biology and Population Genetics of Common Ash (Fraxinus excelsior L.)

    Författare :Grazyna Bochenek; Göteborgs universitet; []
    Nyckelord :Fraxinus excelsior; delayed fertilization; functional dioecy; gender-related grow difference; inbreeding; tree-rings; non random mating; wind-pollination;

    Sammanfattning : Common Ash, Fraxinus excelsior L. (Oleaceae) is a wind-pollinated, wind-dispersed, deciduous tree, commonly occurring throughout Central and Northern Europe. The thesis addresses several questions concerning reproductive biology and factors influencing the genetic richness of ash stands. LÄS MER

  3. 22. Pre- and post-copulatory sexual selection in the fowl, Gallus gallus

    Författare :Hanne Løvlie; Sven Jakobsson; Tommaso Pizzari; Matthew J. G. Gage; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cryptic female choice; Gallus; inbreeding avoidance; mate choice; sexual conflict; sexual selection; sperm competition; Ethology and behavioural ecology; Etologi och beteendeekologi; etologi; Ethology;

    Sammanfattning : The evolutionary goal of individuals is reproduction and sexual selection favours traits improving reproductive success. When males invest less than females in offspring, males have potentially a higher reproductive rate than females. LÄS MER

  4. 23. 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

  5. 24. Sex, Sperm and Speciation : On sexual selection and fertility in hybridizing flycatchers

    Författare :Murielle Ålund née Podevin; Anna Qvarnström; Simone Immler; Leonie Moyle; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; sperm biology; sexual selection; speciation; hybridization; cryptic female choice; fertility; Ficedula flycatchers; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

    Sammanfattning : Sexual reproduction entails complex co-evolution between the sexes, necessary for successful fertilization, ensuring individual and population-level fitness. Interfertility is the main criterion for species definition and understanding speciation requires detailed studies of reproductive barriers. LÄS MER

  7. 25. Cooperation and conflict during reproduction in polyterritorial wood warblers (Phylloscopus sibilatrix)

    Författare :Susanne Stenius; Trond Amundsen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; zoologi; Zoology;

    Sammanfattning : In this thesis, the reproductive strategies of male and female wood warblers are studied. Males which arrived early to the breeding grounds had higher reproductive success than later males. This was due to early males more often mating polygynously than late males. LÄS MER