Sökning: "migratory birds"

Visar resultat 21 - 25 av 43 avhandlingar innehållade orden migratory birds.

  1. 21. Movement ecology of aerial insectivorous birds : Individual-based studies on swifts and nightjars

    Författare :Gabriel Norevik; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; swift; nightjar; Apus; Caprimulgus; tracking; archival tags; GPS; geolocation; multi-sensor logger; migration; continuous flight; route choice; altitude; lunar cycle; seasonality;

    Sammanfattning : Many birds are predisposed to annually undertake movements over large temporal and spatial scales. They have an efficient flight machinery, demonstrate impressive capacities in storing and burning fuel, and they exhibit necessary orientation and navigational skills. LÄS MER

  3. 22. 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

  4. 23. Migration strategies of raptors – spatio-temporal adaptations and constraints in travelling and foraging

    Författare :Roine Strandberg; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; route convergence; loop migration; mortality; spatio-temporal distribution patterns; pre- and post-migratory movements; daily travel routines; satellite tracking; fly-and-forage migration; raptors;

    Sammanfattning : My dissertation is about bird migration and addresses questions about how raptors adapt to the fluctuating environments during the transition seasons between breeding and wintering. The migration is highly affected by local prey abundance, foraging strategies, weather conditions and landscape patterns along the migration routes as well as navigation and orientation mechanisms and cues. LÄS MER

  5. 24. Avian migration: the role of geomagnetic cues

    Författare :Ian Henshaw; Cecilia Kullberg; Thomas Alerstam; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geomagnetic cues; orientation; food intake; fuel deposition; corticosterone; endogenous time program; bird migration; Biology; Biologi; etologi; Ethology;

    Sammanfattning : The regularity and scale of bird migrations has impressed mankind for generations. Birds rely on an inherited migratory program to guide them during the journey; however, recent evidence suggests that additional external cues are necessary. LÄS MER

  7. 25. 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