Sökning: "etologi"

Visar resultat 6 - 10 av 96 avhandlingar innehållade ordet etologi.

  1. 6. Seasonal change in defensive coloration in a shieldbug

    Författare :Aleksandra I. Johansen; Gabriella Gamberale-Stille; Birgitta S. Tullberg; Graeme Ruxton; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Shield bug; colour change; protective coloration; cryptic; aposematic; behavioural change; etologi; Ethology;

    Sammanfattning : Protective coloration such as aposematism and crypsis occurs in many insects but only a few species alter their defensive strategy during the same instar. We hypothesize the adult shield bug Graphosoma lineatum with an alternating black and non-melanised longitudinal striation exhibit such a change in defensive coloration. LÄS MER

  3. 7. Evolution of Mimicry and Aposematism Explained: Salient Traits and Predator Psychology

    Författare :Baharan Kazemi; Olof Leimar; Gabriella Gamberale-Stille; Mike Speed; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; imperfect mimicry; mimicry evolution; predator learning; discrimination; generalization; salience; overshadowing; aposematism; warning signal evolution; generalization bias; peak shift; etologi; Ethology;

    Sammanfattning : Aposematic species have evolved conspicuous warning signals, such as bright colors and striking patterns, to deter predators. Some edible and harmless species take advantage of this deterrent effect by mimicking their appearance. Mimicry is a great example of how natural selection produces remarkable adaptations. LÄS MER

  4. 8. Choice, competition, and interactions between episodes of sexual selection

    Författare :Charel Reuland; John Fitzpatrick; Ingo Schlupp; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; contest competition; sperm competition; mate choice; cryptic choice; sperm quality; reproductive status; social dominance; etologi; Ethology;

    Sammanfattning : Choice and competition are essential parts of evolutionary biology. In an effort to pass their genes from one generation to the next, animals may carefully choose their mating partners, and/or compete for access to mates. LÄS MER

  5. 9. Migratory routes and stopover behaviour in avian migration

    Författare :Robert Stach; Cecilia Kullberg; Sven Jakobsson; Thord Fransson; Åke Lindström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bird migration; migration routes; stopover; geolocator; radio telemetry; tracking; fuel deposition; etologi; Ethology;

    Sammanfattning : Migratory birds, some small and light weight as matchboxes, engage in seasonal inter-continental journeys in order to take advantage of the long summer days and abundance of food at northern latitudes to breed and raise their young, and then escape the harsh winters by migrating to lower latitudes. This thesis deals with two important aspects of migration, the routes taken during migration and the birds’ behaviour at stopovers. LÄS MER

  7. 10. Spring Phenology of Butterflies : The role of seasonal variation in life-cycle regulation

    Författare :Sandra Stålhandske; Olof Leimar; Karl Gotthard; Wolf Blanckenhorn; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Phenology; Life cycle regulation; Phenotypic plasticity; Local adaptation; Butterflies; Diapause; Pupal development; Anthocharis cardamines; Herbivore – host plant interaction; etologi; Ethology;

    Sammanfattning : Animals and plants in temperate regions must adapt their life cycle to pronounced seasonal variation. The research effort that has gone into studying these cyclical life history events, or phenological traits, has increased greatly in recent decades. LÄS MER