Search for dissertations about: "migrating birds"

Showing result 1 - 5 of 29 swedish dissertations containing the words migrating birds.

2. 1. Birds and Borrelia

   Author : Björn Olsen; Umeå universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Borrelia; Ixodes ticks; Birds; Epidemiology; Zoonotisk ekologi; Virology; Mikrobiologi;

   Abstract : The Lyme disease causing spirochaete Borrelia burgdorferi sensu lato is transmitted by ticks within the genus Ixodes. These ticks are liberal host seekers and parasitise mammals, birds and reptiles.Prior to this study, the distribution of I. ricinus ticks and Lyme disease was thought to be restricted to the southern half of Sweden. READ MORE

4. 2. Role of birds in the biology of Lyme disease Borrelia

   Author : Åsa Gylfe; Klaus Kurtenbach; Umeå universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Lyme disease; birds; Borrelia; I. uriae; infection reactivation; stress; bipolar distribution; transequatorial transport;

   Abstract : Lyme disease is a tick-transmitted illness caused by Borrelia burgdorferi sensu lato (s.l.), a group of spirochetes with at least three human pathogenic species, B. burgdorferi sensu stricto, B. READ MORE

5. 3. There and Back Again - nocturnal migratory behaviour of birds during spring and autumn

   Author : Håkan Karlsson; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; migration; seasons; flight; orientation; navigation; behaviour; strategies; birds; nocturnal;

   Abstract : This dissertation explores the migratory behaviour of nocturnally migrating passerines and common swifts (Apus apus). Birds passing Lund (southern Sweden) and Abisko (northernmost Scandinavia) where sampled using tracking radar. The aim has been to investigate potential diverging strategies between spring and autumn migration. READ MORE

6. 4. Fuel and fly: adaptations to endurance exercise in migrating birds

   Author : Anders Kvist; Bröstcancer-genetik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; water balance; flight power; phenotypic flexibility; energy assimilation; basal metabolism; Animal ecology; Djurekologi;

   Abstract : Birds on migration alternate between consuming fuel stores during flights and accumulating fuel stores during stopovers. This thesis highlights some of the ways in which migrating birds have adapted to the different demands of fuelling and flight. Most of the time on migration is spent at stopover sites accumulating fuel stores. READ MORE

7. 5. Bird orientation: external cues and ecological factors

   Author : Johan Bäckman; Evolutionär ekologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; tracking radar; Emlen funnel.; Animal ecology; Djurekologi; oscillatory orientation; roosting flight; scatter; concentration; heading; cue calibration; light dependent; magnetoreception; subcutaneous fat stores; body condition; energetics; geomagnetic field; visual cues; orientation; birds; migration;

   Abstract : Birds are generally capable of accurate orientation. In this thesis I present studies about the external cues and the ecological factors that influences bird orientation. A multitude of environmental cues are used to select and maintain a proper direction. READ MORE