Sökning: "multiple predators"

Visar resultat 1 - 5 av 26 avhandlingar innehållade orden multiple predators.

  1. 1. Predator induced phenotypic plasticity in a freshwater snail

    Författare :Thomas Lakowitz; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; dispersal; Radix balthica; shell morphology; reaction norm; multiple predators; cost of plasticity; intraspecific competition; inerspecific competition;

    Sammanfattning : In this thesis I examined a phenotypically plastic defence in a common freshwater snail, Radix balthica. Adaptive prey defences may involve behavioural, life-history or morphological changes. Snails are important species in freshwater systems. LÄS MER

  2. 2. Multiple stressors in rotifer communities: : Effects of predation, climate change, and brownification

    Författare :Huan Zhang; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate change; community dynamic; brownification; heat wave; inducible defense; rotifer; plasticity; multiple stressors; Predation; prey;

    Sammanfattning : Most organisms on Earth live in an environment where they are exposed to multiple pressures, including predation and climate change. In many aquatic ecosystems, organisms have to handle additional challenges such as brownification, co-occurring with climate warming. LÄS MER

  3. 3. Zooplankton responses to multiple threats within and across generations

    Författare :Yongcui Sha; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Predation; Ultraviolet radiation; Daphnia; copepods; plasticity; maternal effects; adaptation; diel vertical migration;

    Sammanfattning : In their natural environments, organisms are unlikely to be distributed randomly but instead they are constantly faced with multiple and variable threats. In order to maximise survival, they need to be able to perceive the present threat level and respond accordingly. LÄS MER

  4. 4. Phenotypic responses of zooplankton to variable conditions

    Författare :Marcus Lee; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Multiple threats; Plasticity; Risk-Spreading; sexual conflict; ultraviolet radiation; Daphnia; Copepods;

    Sammanfattning : Organisms are continually challenged by multiple threats in the environment, and such threats are seldom constant in either time or space. Therefore, organisms must maintain physiological, behavioural, morphological and life- history adaptations across environments to prevent reductions in fitness. LÄS MER

  5. 5. 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