Sökning: "Evolutionär ekologi"

Visar resultat 1 - 5 av 47 avhandlingar innehållade orden Evolutionär ekologi.

  1. 1. Predator-prey interactions in freshwater systems: The importance of chemical communication

    Författare :Kajsa Åbjörnsson; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi; Hydrobiology; trophic cascades; non-lethal effects; benefits; costs; heredity; predator experience; alarmsubstances; dietary cues; amphibian larvae; invertebrates; visibility; fish; behaviour; Predator-prey; chemical cues;

    Sammanfattning : Predator released chemical cues provide a valuable source of information to prey organisms that can be used to alter their behaviour in order to reduce predation risk. In this thesis, I have examined under what circumstances chemical cues may be used by prey, and if prey discriminate between different cues. LÄS MER

  2. 2. Local adaptive pigmentation in Asellus aquaticus -effects of UV-radiation and predation regime

    Författare :Jonas Johansson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; damselfly; perch; UV-avoidance; isopod; anti-predator traits; evolution; selective predation; limnologi; akvatisk ekologi; Animal ecology; Djurekologi;

    Sammanfattning : Pigmentation in the freshwater isopod Asellus aquaticus differed between two habitats. Asellus were lighter pigmented in stands of submerged stonewort vegetation, than in nearby reed stands. Moreover, Asellus pigmentation became lighter with time in recently established stonewort stands. LÄS MER

  3. 3. Population Dynamics and Conservation of the Sand Lizard (Lacerta agilis) on the Edge of its Range

    Författare :Sven-Åke Berglind; Pekka Pamilo; Per Sjögren-Gulve; Coulson Tim; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Ecology; demography; extinction; habitat; Lacerta agilis; management; metapopulation; peripheral populations; population dynamics; population viability analysis; reintroduction; reptiles; umbrella species; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : The sand lizard (Lacerta agilis) reaches the northern periphery of its distribution in south-central Sweden, where small, isolated relict populations occur in pine heath forests on sandy sediments. Modern forestry and fire suppression have reduced the amount of suitable open habitat for the species in this area and seem to be important for its decline. LÄS MER

  4. 4. Evolutionary Resolutions of Conflicts with Mates and Offspring

    Författare :Roger Härdling; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Clutch evolution; Arms race; Idothea baltica; Evolutionary conflicts; Sexual conflicts; Parent-offspring; Endosperm; Ecology; Ekologi;

    Sammanfattning : In sexual conflicts and conflicts between parents and offspring, natural selection acts in different directions on the two sides. For example, males may be selected to achieve many mates, but female fitness may be maximised by monogamy. In this thesis I study the evolutionary outcome of these situations mainly by theoretical modelling. LÄS MER

  5. 5. Avian thermoregulation across age and seasons

    Författare :Fredrik Andreasson; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ambient temperature; body temperature; Cyanistes caeruleus; energy expenditure; hypothermia; life-history theory; metabolic rate; Parus major; thermoregulation; trade-off; winter ecology;

    Sammanfattning : Animals constantly need to relate to prevailing environmental conditions and regulate their body temperature accordingly. Body temperature regulation in birds and mammals is inherently linked to energy expenditure and, thus, thermoregulation is a physiological mechanism that could trade-off with other costly processes, with potential long-term fitness consequences. LÄS MER