Sökning: "reproductive effort"
Visar resultat 1 - 5 av 33 avhandlingar innehållade orden reproductive effort.
Sammanfattning : This study focuses on various aspects of costs of reproduction and the evolution of energetic breeding tactics. It emphasizes the distinction between demographic costs of reproduction expressed already before current offspring have reached independence (prebreeding costs), and costs expressed only after offspring independence (postbreeding costs). LÄS MER
2. Costs, benefits and constraints in the evolution of avian reproductive tactics: a study on the blue tit
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
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
Sammanfattning : Age is often a neglected factor in ecological studies. However, age-related changes in reproduction and survival of organisms may strongly influence population dynamics. LÄS MER
5. Reproductive allocation and costs of reproduction in subarctic herbs : A resource-based perspective
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