Sökning: "Reproductive allocation"

Visar resultat 1 - 5 av 27 avhandlingar innehållade orden Reproductive allocation.

  1. 1. Costs, benefits and constraints in the evolution of avian reproductive tactics: a study on the blue tit

    Författare :Erik Svensson; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; reproductive timing; selection analysis; natural selection; mate quality; nestlings; sex ratio; DNA-content; flow cytometry; ELISA; BMR; energetics; immunocompetence; immune system; sexual conflict; nestling mortality; thermoregulation; moult; reproductive costs; reproductive effort; Parus caeruleus; blue tit; birds; juvenile survival; laying date; food supply; Animal ecology; Djurekologi;

    Sammanfattning : In this study I have investigated the various factors influencing reproductive tactics among breeding blue tits (Parus caeruleus). The study was carried out in a nestbox-breeding population of marked individuals at the Revinge Area, outside Lund, southern Sweden. LÄS MER

  3. 2. Reproductive allocation and costs of reproduction in subarctic herbs : A resource-based perspective

    Författare :Åsa M. Hemborg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Altitudinal gradient; Plant size; Predispersal seed predation; Reproductive effort; Resourcedynamics; Seasonal variation; Sexual dimorphism; Somatic costs; Unisexual plants; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : The influence of internal and external factors on two major plant life history components, i.e., reproductive allocation and costs of reproduction, was examined for nine perennial herbs in subarctic Swedish Lapland. In one study, comparisons were made between Sweden and the French Alps. LÄS MER

  4. 3. Living in a Variable Environment : Reproductive Decisions in Wild Bird Populations

    Författare :Mårten B. Hjernquist; Lars Gustafsson; Marcel Visser; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; evolutionary ecology; competition; sex allocation; paternity; EPP; inadvertent social information; migration; breeding density; territory quality; territory availability; great tit; blue tit; Ficedula albicollis; Biology; Biologi; Animal Ecology; zooekologi;

    Sammanfattning : In nature, environments are often variable and heterogeneous influencing ecological and evolutionary processes. This thesis focus on how animals interact with their environment and how that affects the reproductive decisions they make. LÄS MER

  5. 4. Metapopulations dynamics and sex-specific resource allocation in Silene dioica

    Författare :Elisabet Peedu; Pär Ingvarsson; Barbara Giles; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Silene dioica; Skeppvik Archipelago; Metapopulation Dynamics; Population Genetic Structuring; Genetic Diversity; Gene Flow; Sex-Specific Resource Allocation; Cost of Reproduction; Life-History Theory; Sexual Dimorphism; Reproductive Effort; biology; biologi; evolutionär genetik; evolutionary genetics; ekologisk botanik; Ecological Botany;

    Sammanfattning : Rising archipelagos provide unique settings for the study of the temporal and spatial dynamics of their biota. This offers the possibility to study the ecology and genetics of early successional processes; both between islands that differ in age and within islands when already established organisms have to keep pace with the changing environment. LÄS MER

  7. 5. Pollinators, Enemies, Drought, and the Evolution of Reproductive Traits in Primula farinosa

    Författare :Per Toräng; Jon Ågren; Johan Ehrlén; Rebecca Irwin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ecology; Alternative reproductive strategies; climate change; facilitation; floral display; flowering phenology; frequency-dependent selection; genetic diversity; life-history strategies; local adaptation; pollination; predation; Primula farinosa; reproductive effort; soil disturbance; stochastic growth rate; Ekologi;

    Sammanfattning : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits and population differentiation in the insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically, I (1) determined whether the effects of floral display and interactions with pollinators and seed predators, and plant reproductive success were frequency-dependent and affected by surrounding vegetation context, (2) examined the consequences of intermittent drought years on population dynamics using numerical simulations based on demographic data collected over seven years, (3) analyzed among-population differentiation in flowering phenology and reproductive allocation, and its relationship to soil-depth at the site of origin. LÄS MER