Sökning: "clutch size"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden clutch size.

1. 1. Nesting and migration in the introduced Canada goose in Sweden

   Författare :Göran Sjöberg; Catherine M. Lessells; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Species introductions; DNA fingerprinting; natal dispersal; breeding dispersal; bird migration; wintering areas; clutch size; laying date; body reserves; nest defence; waterfowl; Canada goose; Anatidae; Branta canadensis;

   Sammanfattning : The aim of the thesis was to document patterns in breeding and migration in Swedish Canada geese Branta canadensis, to explain these against the genetic and historical background of the population, and to test predictions of hypotheses pertaining to parental investment.The Canada goose population in Sweden was founded by the introduction of a few individuals in the 1930's. LÄS MER

3. 2. 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

4. 3. The effects of temperature on avian physiology, behavior and development

   Författare :Andreas Nord; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; clutch size; Cyanistes caeruleus; ecological immunology; energy expenditure; fever; Ficedula hypoleuca; heterothermy; hypothermia; incubation; life history; metabolic rate; Parus major; RMR; Taeniopygia guttata; temperature; winter;

   Sammanfattning : Temperature is a property of profound matter in all aspects of animal life, affecting both individual energy budgets and the environments in which animals reside. Thus, a proper understanding of the effects of temperature variation is instrumental in understanding not only animal form and function, but also the structure and dynamics of wild populations. LÄS MER

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

   Författare :Roger Härdling; Biologiska institutionen; []
   Nyckelord :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

7. 5. The mechanisms of metal expansion penetration during solidification of grey cast iron

   Författare :Izudin Dugic; Preben Norgaard Hansén; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Grey cast iron; solidification; solidification modelling; graphite expansion; molar volume; casting simulation; thermal analysis; thermoanalysis cup; casting temperature; inoculation; inoculant; metal expansion penetration; eutectic cell size; primary austenite; austenite grain; TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : The production of high quality castings requires the casting surface to be clean and free from defects. One type of defect often found is caused by metal penetration into the sand mould. LÄS MER