Sökning: "bird migration"

Visar resultat 1 - 5 av 39 avhandlingar innehållade orden bird migration.

  1. 1. Individual consistency in bird migration

    Författare :YANNIS VARDANIS; Evolutionär ekologi; []
    Nyckelord :bird migration; telemetry; bird ringing; individual consistency; repeatability; site fidelity; routes; timing; annual cycle; meta-analysis;

    Sammanfattning : Slight differences, which appear in the individual animals of the same species and population have been recognised and appreciated ever since Darwin. These consistent intra-specific differences in animals have been considered very important because they are often inherited, and thus, provide the basic material for evolution to act on. LÄS MER

  3. 2. Flight Behaviour of Passerines on Nocturnal Migration

    Författare :Cecilia Nilsson; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bird migration; Passerines; Flight Behaviour; Tracking radar; Optimal migration; Flight speed; Airspeed; Wind drift; Nocturnal migration; Coastline effects; Flight directions; Reverse migration;

    Sammanfattning : Many passerines migrate during the night and at high altitudes, making their migration difficult to observe. By using tracking radars we have been able to make exact observations of the flight behaviour of passerines on nocturnal migration, which has enabled us to test several hypotheses about adaptive values and constraints regarding migratory behaviour in different ecological contexts. LÄS MER

  4. 3. Ecology and evolution of large-scale bird migration patterns : A natural history and comparative study of the migration in common and little ringed plovers

    Författare :Linus Hedh; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ringed plover; leap-frog migration; migration speed; migration process; light level geolocator; migration;

    Sammanfattning : Migration distance and seasonal redistribution patterns may vary between and within bird populations. A common pattern is leap-frog migration, in which northerly breeding populations migrate farther and winter south of more southerly breeding populations. LÄS MER

  5. 4. The Problem of Partial Migration - the Case of the Blue Tit

    Författare :Anna Nilsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Naturvetenskap; Natural science; Djurekologi; Animal ecology; Ekologi; Ecology; weather; personality; partial migration; metabolic rate; evolution of migration; dominance; Cyanistes caeruleus; climate change; blue tit; behavioural strategies; bird migration;

    Sammanfattning : In the evolution of bird migration, partial migration is assumed to be an important intermediate step between migration and residency. Partial migration is characterised by the existence of both migratory and resident individuals in a given population. LÄS MER

  7. 5. Evolutionary dynamics of migration and breeding in wild birds: genetic architecture, sexual conflicts and evolutionary constraints

    Författare :Maja Tarka; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantitative genetics; heritability; intralocus sexual conflict; antagonistic selection; QTL; G-matrix; wing length; arrival date; migration; geolocator; bird; Acrocephalus arundinaceus;

    Sammanfattning : Our knowledge of the evolutionary potential of traits involved in different selective episodes, especially in natural populations, is still limited. This is true for questions such as the genetic basis and inheritance of traits, how natural and sexual selection acts on them, and how selective conflicts influence the evolutionary response to selection. LÄS MER