Sökning: "Djurekologi"

Visar resultat 31 - 35 av 57 avhandlingar innehållade ordet Djurekologi.

  1. 31. Development and maintenance of quality indicators in pheasants

    Författare :Thomas Ohlsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PHA; ELISA; immunocompetence; carotenoid coloration; male ornaments; fluctuating asymmetry; growth; early development; Phasianus colchicus; egg size; sexual selection; Animal ecology; Djurekologi; Ecology; Ekologi;

    Sammanfattning : Females often base their choice of mates on the expression, size or intensity, of male sexual ornaments. Indicator models of sexual selection assume that females assess male genetic quality through the expression of these secondary sexual characters. LÄS MER

  3. 32. Through the eyes of a woodpecker: Understanding habitat selection, territory quality and reproductive decisions from individual behaviour

    Författare :Ola Olsson; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; reproductive success; territory quality; habitat selection; giving-up density; Bayesian processes; foraging; Picidae; lesser spotted woodpecker; Dendrocopos minor; conservation; Animal ecology; Djurekologi;

    Sammanfattning : In this thesis I present some connections between foraging behaviour and reproductive success, time budget, tree species use, and habitat selection. The thesis is based upon both theoretical and empirical work. All empirical studies concern a south Swedish population of lesser spotted woodpeckers Dendrocopos minor, studied between 1990 and 1996. LÄS MER

  4. 33. Population ecology and management of waders breeding on coastal meadows

    Författare :Richard Ottvall; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal ecology; Djurekologi; grazing management; population modelling; demography; genetic structure; population decline; Tringa totanus;

    Sammanfattning : Many wader (Charadrii) populations are declining throughout in Europe, but the underlying causes are often poorly known and diverse. To fully grasp the reasons behind declines in vulnerable wader populations, it is crucial to understand the demography. LÄS MER

  5. 34. Parental and embryonic behaviours in precocial birds

    Författare :Irene Persson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pheasants; growth rate; oxygen consumption; hatch synchronization; incubation behaviour; nest predation; physical condition; Egg laying; primary sex ratio; mallards; Animal ecology; Djurekologi;

    Sammanfattning : This thesis deals with behaviours during reproduction in precocial birds, both from the perspective of the female and of the embryos. Female pheasants in good physical condition laid larger eggs and produced a higher proportion of daughters than females in poor condition. LÄS MER

  7. 35. The Threat to the Baltic Salmon - a Combination of Persistent Pollutants, Parasite and Oxidative Stress

    Författare :Maria Persson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Salmo salar; Atlantic salmon; polychlorinated biphenyls; Animal ecology; akvatisk ekologi; limnologi; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; lake Vänern; lake Vättern; Baltic Sea; Eubothrium crassum; aryl hydrocarbon receptor; AHR; consumption advice; stable isotopes; astaxanthin; EROD; M74; antioxidants; biomagnification; cestodes; parasites; DDT; Djurekologi; Environmental chemistry; Miljökemi; PCB;

    Sammanfattning : Atlantic salmon (Salmo salar) from the Baltic Sea suffer from a reproduction disease known as the M74-syndrome. Newly hatched fry develop nerve disorders and die between 3-5 days after the first symptoms are seen. This is a maternally transmitted disease that is casued by a thiamine (vitamin B1) deficiency. LÄS MER