Sökning: "nest predation"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden nest predation.

  1. 1. Behaviour and life-history responses to chick provisioning under risk of nest predation

    Författare :Sönke Eggers; David Winkler; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Chick provisioning; clutch size; delayed dispersal; nest concealment; nest predation; parental care; population decline; Perisoreus infaustus; Siberian jay; Biologi; Biology; Biologi; populationsbiologi; Population Biology;

    Sammanfattning : This thesis examines risk management in breeding Siberian jays (Perisoreus infaustus), which is indigenous to the northern taiga. Parent behaviour and the nest are cryptic. A new nest is built each year. It is placed on spruce or pine branches close to the trunk and well insulated with lichens, feathers and reindeer hair. LÄS MER

  3. 2. Predation and shorebirds: predation management, habitat effects and public opinions

    Författare :Daniel Isaksson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conservation; waders; predation; coastal pastures; redshank; lapwing; attitudes; human dimensions;

    Sammanfattning : Many shorebird populations are rapidly declining and a high nest predation rate is one of the threats facing these populations. Thus, factors that affect predation and how to manage it in an effective way are receiving increased attention. LÄS MER

  4. 3. Habitat selection, nest predation and conservation biology in a Black-tailed Godwit (Limosa limosa) population

    Författare :Tomas Johansson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Black-tailed godwit; Limosa limosa; nest site selection; nest predation; philopatry; risk analysis; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

    Sammanfattning : This thesis focuses on a black-tailed godwit (Limosa limosa) population, consisting of 35-40 pairs, that breeds on a grazed shore meadow on SE Gotland, Sweden. The small size of the population makes it more prone to extinction due to chance events, than a larger population.The godwits showed microhabitat preferences when choosing nest sites. LÄS MER

  5. 4. Cycles of voles, predators, and alternative prey in boreal Sweden

    Författare :Birger Hörnfeldt; S. Erlinge; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; 3-4 year cycles; Clethrionomys glareolus; Clethrionomys rufocanus; Microtus agrestis; snap-trapping; rate of change; population regulation; delayed density-dependence; time-lag mechanism; seasonality; predation; food; predator avoidance; foraging behaviour; Aegolius funereus; nest boxes; numerical response; nomadism; Vulpes vulpes; Sarcoptes scabiei vulpes; Lepus timidus; Francisella tularensis; Tetraonidae; hunting statistics; zooekologi; Animal Ecology;

    Sammanfattning : Bank voles, grey-sided voles, and field voles had synchronous 3-4 year density cycles with variable amplitudes which averaged about 200-fold in each species. Cycles of vole predators (red fox and Tengmalm's owl), and their (foxes') alternative prey (mountain hare and forest grouse) lagged behind the vole cycles. LÄS MER

  7. 5. 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