Sökning: "males"

Visar resultat 31 - 35 av 918 avhandlingar innehållade ordet males.

  1. 31. Influence of Mate Quality on Reproductive Decisions in a Fish with Paternal Care

    Författare :Niclas Kolm; Anders Berglund; Ben Sheldon; Kai Lindström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; sexual selection; differential allocation; evolution of egg size and parental care; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : Female reproductive decisions have been suggested to be highly influenced by mate quality. I have studied whether offspring quality may be adjusted by females to match the attractiveness of males and how strong control females have over their reproductive investment focusing on egg size. LÄS MER

  3. 32. Sexual selection in Pomatoschistus – nests, sperm competition, and paternal care

    Författare :Ola Svensson; Charlotta Kvarnemo; Sigal Balshine; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Female choice; Filial cannibaism; Gobiidae; Nests; Paternal care; Pomatoschistus microps; Pomatoschistus minutus; Sexual selection; Sperm competition; Teleostei; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : Sexual selection arises through variation in reproductive success. This thesis investigates different aspects important in sexual selection, namely nest building, sperm competition, paternity and paternal care, and their mutual interrelationships. LÄS MER

  4. 33. Brood sex ratio and sex differences in Tengmalm’s owl : (Aegolius funereus)

    Författare :Tim Hipkiss; Gary Bortolotti; Umeå universitet; []
    Nyckelord :Aegolius funereus; avian CHD1 genes; brood sex ratio; differential mortality; nomadism; northern Sweden; sexual size dimorphism; sibling rivalry; supplementary feeding; vole cycles; zooekologi; Animal Ecology;

    Sammanfattning : Males and females differ in morphology and behaviour, so that selection acts differently on the two sexes. This changes the relative reproductive success of males and females, and it is beneficial for parents to bias the sex ratio of their broods in favour of the sex with the best survival and breeding prospects. LÄS MER

  5. 34. Cryptic Female Choice and Male Mating Behaviour : Sexual Interactions in Beetles

    Författare :Martin Edvardsson; Göran Arnqvist; Paul Ward; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Cryptic female choice; Copulatory courtship; Harmful male traits; Nuptial gifts; Sperm competition; Sexual selection; Tribolium castaneum; Callosobruchus maculatus; Biologi; Biology; Biologi;

    Sammanfattning : The importance of cryptic female choice, i.e. female post-copulatory influence over male reproductive success, in driving the evolution of male traits remains controversial. The main aim of this thesis was to understand the post-copulatory consequences of sexual interactions and the importance of cryptic female choice in two species of beetle. LÄS MER

  7. 35. Mutual Mate Choice in the Deep Snouted Pipefish Syngnathus typhle

    Författare :Maria Widemo; John D. Reynolds; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Sexual selection; mutual mate choice; mate competition; sex role reversal; parental investment; Biologi; Biology; Biologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis integrates the fields of sexual selection, parental investment and sex role theory by investigating mutual mate choice and mate competition in the sex role reversed deep snouted pipefish Syngnathus typhle (Pisces: Syngnathidae) through a series of laboratory experiments. In S. LÄS MER