Mastergradsoppgaver i biologi: Recent submissions

Now showing items 401-420 of 427

    • Potential effects of two stressors on morphological traits of Northern Goshawk (Accipiter gentilis) nestlings 

      Schnug, Lisbeth (Master thesis; Mastergradsoppgave, 2009-01)
      Anthropogenic and natural stressors can affect ecosystems negatively and it is therefore important to have a clear understanding of the responses of organisms to stressors. The Northern Goshawk (Accipiter gentilis) is a common raptor species of the boreal forest ecosystem and its location at the top of its food chain makes it a special target for two important stressors; endoparasitism and environmental ...

    • Olje fra raudåte (Calanus finmarchicus). Oksidativ stabilitet, fettklasser og karotenoidinnhold. 

      Pedersen, Alice Marie (Master thesis; Mastergradsoppgave, 2007-11-28)
      I senere tid har oppmerksomhet blitt rettet mot fangst av raudåte i de norske havområdene. Det er utviklet egne fangst og prosesseringsteknikker, og bruksområdene for raudåteproduktene kan være mange. Olje utvunnet fra raudåte har et høyt innhold langskjedede n-3 fettsyrer, voksestere og naturlige antioksidanter. Hensikten med oppgaven var å undersøke oljens oksidative stabilitet ved langtidslagring, ...

    • The role of white wing bands in parental care and mate choice in the female Common eider (Somateria mollissima) 

      Hoholm, Marte Sørbø (Master thesis; Mastergradsoppgave, 2008-11-15)
      The female Common eider (Somateria mollossima) is a drab, lightly coloured bird, easily distinguished from the brightly ornamented male. Unlike the male, the female has white bands on the tips of her wings, and these white wing bands have been shown to reflect individual quality in previous studies. In this study the potential role of the white wing bands in parental care and mate choice is studied, ...

    • "Parasitized by your own kind" : the life of the Svalbard Eider (Somateria mollissima) 

      Hagen, Jeanette Iren (Master thesis; Mastergradsoppgave, 2008-11-15)
      Conspecific brood parasitism is a subtle reproduction tactic often performed by many species. The parasitizing females lay eggs in the nest of another female of the same species, and the hosting female then incubates and raises both her own and the parasite’s offspring. Is it highly discussed why the hosting females allow this parasitism, whether she is able to detect it, or if she receives more ...

    • Pseudocalanus in Svalbard waters : identification and distribution patterns of two sibling copepod species 

      Gudmundsdottir, Ragnhildur (Master thesis; Mastergradsoppgave, 2008-11-05)
      Marine copepods of the genus Pseudocalanus (Calanoida) are common in Svalbard waters as well as throughout the northern hemisphere. They contribute considerably to plankton biomass in addition to Calanus spp. and play an important role in the marine food web as a link between planktivores, such as fish larvae, and microalgae. Pseudocalanus consists of several sibling species, and two of them, ...

    • Kjønnsspesifikk overlevelse av unger hos gråmåke Larus argentatus og svartbak Larus marinus 

      Jenssen, Trond Ragnar Skog (Master thesis; Mastergradsoppgave, 2008-03)
      Det er i dag gode bevis for at fugler har muligheter til å endre kjønn på avkom kjønns ratio) i forhold til en rekke miljøfaktorer. Dette kan skje enten ved at de produserer et overskudd av egg med unger av det ønskede kjønn (primær kjønns ratio), eller at de manipulerer kjønns ratio etter klekking ved å differensiere innvesteringa (eks. mating) i favør av det ene kjønnet sekundær kjønns ratio). ...

    • Nest site selection by northern goshawk Accipiter gentilis in northern coastal birch forests 

      Andersen, Ellen F. (Master thesis; Mastergradsoppgave, 2008-06-03)
      Most studies of nest site selection by northern goshawk, Accipiter gentilis, have been done in mixed – or coniferous forests, and emphasis has been put on the importance of large trees and relatively intact, old forest stands for nesting sites. However, goshawks in northern Norway are found in birch forests characterized by relatively small trees and a high natural level of fragmentation. In this ...

    • Norwegian hook designs improve catch efficiency in the Adriatic bottom longline fishery 

      Tatone, Ivan (Master thesis; Mastergradsoppgave, 2008-05-15)
      The present study reports the results of investigations conducted during 2006-2007 of the bottom longline fishery in the Southern Adriatic Sea. The study investigated the rigging of the line and the material used. These investigations specifically compared the catch efficiency of the traditionally used J-shaped hook to hooks with innovative design that are commonly used in the Norwegian costal ...

    • The role of the Hooded Crow (Corvus corone) in the nesting success of the Common Eider (Somateria mollissima) at two colonies in Troms county, Northern Norway 

      Stien, Jennifer (Master thesis; Mastergradsoppgave, 2008-05)
      There is evidence of a negative population trend for the two neighbouring eider colonies of Håkøya and Grindøya in Troms county, northern Norway. Casual observations suggest that nest predation may be an important factor, and that the hooded crow in particular could be the main egg predator. On this basis, a two year pilot study was conducted to investigate the role of the hooded crow in the nest ...

    • The spatial relationship between pelagic fish species in the Barents Sea 

      Haukeland, Vegard Bjartveit (Master thesis; Mastergradsoppgave, 2008-05-15)
      Capelin (Mallotus villosus) is a pelagic fish species with large interannual stock variations in the Barents Sea ecosystem. Together with polar cod (Boreogadus saida) and juvenile herring (Clupea harengus), it functions as an intermediate link that transfers energy from zooplankton to higher trophic levels. Capelin is a key prey and important as a food resource both to sea birds, sea mammals and ...

    • Habitat use and feeding behaviour of harbour seals (Phoca vitulina) in Vesterålen 

      Ramasco, Virginie (Master thesis; Mastergradsoppgave, 2008-05-28)
      A pilot project was carried out by the Institute of Marine Research (IMR) to test the functionality of GPS phone tags (by SMRU) on harbour seals (Phoca vitulina) in the Vesterålen archipelago, Norway. Acoustic surveys were performed to investigate the abundance of fish in these waters and scat sampling was used to assess the diet composition of the seal population inhabiting the area. Five juvenile ...

    • Comparative feeding ecology of the sympatric cod fishes Arctogadus glacialis and Boreogadus saida in North East Greenland evaluated from diet and stable isotope analyses 

      Joensen, John (Master thesis; Mastergradsoppgave, 2008-02-15)
      The fish fauna was investigated in autumn 2003 during the TUNU-I Expedition to NE Greenland fjords. Two gadoids Arctogadus glacialis and Boreogadus saida were abundant in many trawl hauls. In this study, the stomach contents and the stable isotope composition were determined in 60 Arctogadus glacialis and 50 Boreogadus saida from Tyrolerfjord and Dove Bugt. The diets were examined by Stomach Contents ...

    • Initielle studier av Mll3104 og Mll3105 fra Mesorhizobium loti : proteiner antatt involvert i katabolisme av trehalose 

      Havdalen, Linda J. (Master thesis; Mastergradsoppgave, 2007-12)
      Rhizobiacea utgjør en bakterieslekt der de fleste medlemmene er i stand til å inngå symbioser med diverse legumer. Slekten innbefatter Rhizobium, Sinorhizobium, Mesorhizobium, Bradyrhizobium og Azorhizobium, og kollektivt omtales disse for rhizobia. Partnerskapet med legumer er av mutualistisk karakter, der mikrosymbionten bidrar med fiksert nitrogen i form av NH3, og planteverten sørger for en ...

    • Spatial distribution of mammals in relation to spruce plantations in birch forests of northern Norway 

      Juell, Kristoffer Hovind (Master thesis; Mastergradsoppgave, 2007-11)
      Spruce plantations in coastal birch forests of northern Norway might affect the spatial activity of mammals in the landscape. To investigate this relationship, I censused tracks of mammals in the winter according to the Finnish wildlife triangle method and analysed these at three spatial scales; tree stand level, landscape level and regional level, the two first being related to spruce. The spatial ...

    • Populasjonsstruktur og morfologi hos kongsnegl Buccinum undatum L. på to lokaliteter i Balsfjorden, Nord-Norge 

      Juliussen, Helene Ovedie (Master thesis; Mastergradsoppgave, 2007-11-16)
      To lokaliteter i Balsfjorden, Nord-Norge ble sammenlignet med hensyn på fangstmengde, populasjonsstruktur og morfologi til kongsnegl (Buccinum undatum). Til innsamling ble det benyttet walisiske snegleteiner som var egnet med fisk/sild og haneskjell i kombinasjon eller kun fisk/sild. Fangst foregikk månedlig fra mars til og med juni 2004, på 15, 30 og 45 m dyp. Fangsttiden var på 1 døgn. Antall og ...

    • Immunostimulants connecting innate and adaptive immunity in Atlantic salmon (Salmo salar) 

      Hølvold, Linn Benjaminsen (Master thesis; Mastergradsoppgave, 2007-11-15)
      The use of immunostimulants in fish farming has received increased attention due to the discovery of Toll-like receptors (TLRs) and pattern recognition receptors (PRRs). These receptors have been found to bind to highly conserved motifs on the surface of pathogens, known as pathogen associated molecular patterns. Most of the studied PAMPs activate antigen presenting cells (APCs) together with naïve ...

    • Vertikalt habitatbruk, næringsvalg og vekst hos en innsjølevende bestand av ørret (Salmo trutta L.) i Pasvikvassdraget 

      Johannessen, Karin Strand (Master thesis; Mastergradsoppgave, 2007-10-16)
      En av våre nordligste fiskespisende ørretbestander finnes i Pasvikvassdraget i Finnmark. Omfattende regulering av vassdraget har virket negativt på bestanden, og den blir nå opprettholdt gjennom årlige utsettinger. På 1990-tallet innvandret lagesild fra Enare-sjøen, og den ser ut til å ha hatt positiv effekt på ørreten. Denne undersøkelsen omhandler habitatbruk, næringsvalg og vekst hos innsjølevende ...

    • The challenge of identifying and conserving valuable ecosystems close to human settlements in a northern area. An approach based on field- and satellite data. 

      Stabursvik, Ellen Margrethe (Master thesis; Mastergradsoppgave, 2007-08)
      The rich broadleaved forests of North Norway have high species diversity. Mappings of biodiversity have been undertaken in the two municipalities Målselv and Bardu, but these mappings are far from exhaustive. This study examines classification methods for mapping rich broadleaved forests with the use of Landsat ETM+ images, and with vegetation indices as ancillary data. Three classifications were ...

    • Habitatvalg og beitestrategi hos overvintrende fjæreplytt (Calidris maritima) 

      Gabrielsen, Heidi K. (Master thesis; Mastergradsoppgave, 2007-06-26)
      Fjæreplytt (Calidris maritima) er verdens nordligste overvintrende vader og oppholder seg gruppevis i fjæresonen i Tromsøområdet gjennom vinteren. En flokk fjæreplytt ble observert å konsekvent bytte beitehabitat mellom dag og natt. Ved hjelp av radiosendere og individuelle ringmerker ble natthabitat avdekket og flokken verifisert som den samme i begge habitat. For å undersøke hva som kunne styre ...

    • Livssyklus hos løpebiller (Coleoptera, Carabidae) i en temperaturgradient i Nord-Norge 

      Hanssen, Vibeke Kristin Gellein (Master thesis; Mastergradsoppgave, 2007)
      Endringer i livssyklus hos løpebiller (Coleoptera, Carabidae) ble undersøkt langs en høydegradient i en subarktisk bjørkeskog i Nord-Norge, og funnene ble sammenlignet med studier som har blitt gjort av de samme artene på sørligere breddegrader. Av de 6 artene vi undersøkte var det kun en art som endret tidspunkt for reproduksjon med økende høyde. Patrobus assimilis hadde en interaksjon mellom ...