Abstract In temperate areas, we tend to see an advancement of spring as the global climate is changing at a rate that may be hard for long distance migrant birds to track. Caterpillars are the most common prey type for ...

Phleum pratense (timotei) dyrkes kommersielt som fôr til husdyr. Soppendofytter er vanlig i alle planter, der de har ulike egenskaper som kan påvirke verten samt herbivorer, for eksempel med toksiner. Kunnskapshull i forhold ...

Fuglesang er gjentatte ganger blitt vist å være et seksuelt selektert trekk som kan reflektere aspekter av hannlig kvalitet. Lærte sangtrekk, som for eksempel repertoarstørrelse, er foreslått å ha kostnader knyttet til ...

Fuglesang blir generelt betraktet som et seksuelt selektert trekk, og hos mange sangfuglarter er hunner vist å foretrekke hanner med høy sangytelse eller kompleks sangstruktur. Utviklingsstresshypotesen foreslår at lærte ...

A total of 20 water traps were set out at four locations around Longyearbyen on the High Arctic island Spitsbergen. The traps sampled aerially dispersed invertebrates during the summer of 2008. These trapping locations ...

Aposematism is a defence system used by toxic animals where the animals use warning colouration, often combined with warning gestures, to fend off predators. The most probable scenario is that the toxicity was developed ...

In many species of birds, the quality of the nest site may have important fitness consequences. The focus of the present study was to see if nest box choice in blue tits (Cyanistes caeruleus) and great tits (Parus major) ...

The northern blue whiting is a small mesopelagic gadoid, widely distributed in the north‐east Atlantic. The fishery on this species is extensive and is of commercial importance for several states, also Norway. There have ...

During the last 50 years several changes has occurred in the flora of Oslofjord region. The Crambe maritima populations in the Oslofjord region have increased in size and number, the Eryngium maritimum populations seem ...

Variation in behavioral traits may be genetically or environmentally determined, or both. Previous studies on nest building behaviour in captive birds have proposed that nest building is mainly genetically determined. ...

An upper Ordovician (upper Sandbian) benthic Paleozoic fauna at Langesund in the Oslo graben area has been reviewed. The study area consisted of the uppermost 13 meters of sediments in the Fossum Formation. A species/plot ...

Summary The genetic concerns in conservation biology arise from the deleterious effects of small population size, which is a consequence of loss of genetic diversity through genetic drift and inbreeding. The endangered ...

The nutritional stress hypothesis formulated by Nowicki et al. (1998) is based on the findings that brain structures underlying song learning in songbirds largely develop during the first few months post-hatching; a period ...

The dramatic increase of the red deer (Cervus elaphus) harvest in Norway the recent decades have led to concerns of possible oversized populations, and negative density effects on animal life history traits have been ...

A challenge in ecotoxicology is the translation of individual-level effects of exposure, as measured in for instance laboratory tests, into population-level effects that have more ecological relevance. It is not necessarily ...

Many freshwater fishes are fragmented into local populations. Brown trout (Salmo trutta) is a fish that express high genetic heterogeneity and are known to be structured into genetically differentiated subpopulations ...

Divergent selection pressures, induced by variations in environmental conditions, can be expected to favour different phenotypic expressions. Different populations show thus often local adaptations that could be attributed ...

Summary The anti-predatory behaviour displayed by female Great Tit (Parus major) and Blue Tit (Cyanistes caereleus) in the nestbox was studied to observe possible differences in response between the species, and also ...

I dette studiet undersøkte jeg overlevelsestrender hos elgkalver og voksne elgkuer på Koppang i Hedmark fylke, sør-øst i Norge. Ulv var tilstede i området det meste av studieperioden, men antall ulveflokker endret seg noe ...

Many fish stocks today are declining due to the heavy harvesting and the increasingly demand for more food caused by the growing human population. Life-history trait as age and size at maturity are affected, the fish are ...

Separate gytedemer av harr har etablert seg over 20-25 generasjoner i Lesjaskogsvatn, Oppland fylke. Gytebekkene har konsistent ulike temperaturregimer. Nylige undersøkelser indikerer motgradient veksttilpasning i tidlige ...

The coastal cod is an important commercial and recreational resource for the local communities in the Skagerrak. The situation of this and neighbouring stocks has worsened for decades, promoting an imperative need for ...

Understorey vegetation changes between 1997 and 2005 were studied using 100 permanent plots (1 m2) in four boreal spruce forest stands situated within a National Nature Reserve in SE Norway. The stands differed with respect ...

Great tit nestlings won’t thrive in nests of the pied flycatcher, even though the opposite has been proven successful. In order to explore some of the reasons why, we performed cross fostering experiments where great tit ...

The red deer (Cervus elaphus) are among the most important game species in Norway, with a tenfold increase in harvest over the last few decades. Despite its importance, information regarding red deer habitat selection is ...

Breeding habitat-choice in two closely related species of passerines, Great Tit (Parus major) and Blue Tit (Cyanistes caereleus) was studied to reveal if their habitat preferences primarily is a hereditary trait, or if ...

1. Many studies have dealt with home range and migratory patterns of Cervid species, but there are few explicit analyses quantifying migratory patterns and home range size as a result of habitat. Red deer is known to perform ...

In my experiment I studied domestic chicks (Gallus gallus domesticus) to find out how different sounds and colours affect their behaviour in a feeding process. Previous studies have found the wasp’s buzzing to be a negatively ...

Abstract In the recent decades large carnivores have started to recolonize former occupied areas in North America and in Europe. Increases in predator population sizes can affect the whole ecosystem functioning, but little ...

Snow leopards (Uncia uncia) inhabit the remote mountain ranges of the Himalayas, and are currently listed as Endangered. Due to their inaccessible habitat and sparse distribution it is difficult to compile exact estimates ...

During three subsequent reproductive seasons with contrasting food availability, the King Penguin Aptenodytes patagonicus responses were monitored in a small colony at Husvik, South Georgia. Observations of metal flipper ...

Abstract The heterospecific attraction hypothesis suggests that migrants cue on residents with similar ecological needs to find suitable breeding sites, and that they have reproductive fitness benefits from doing so. In ...

Abstract A lot of studies have been performed on demographic changes in ungulate population due to density dependence, but little is done on density dependent changes in foraging behaviour which can be a mechanism of such ...

The aim of this study was to investigate to what extent population density and small scale habitat variability affect somatic growth of resident, stream-living brown trout Salmo trutta. There is an ongoing debate whether ...

To test if dispersers use odour to discriminate between familiar and unfamiliar individuals male and female root voles (Microtus oeconomus) were given the opportunity to choose between one familiar and one unfamiliar test ...

It is stated that the feral American mink (Mustela vison), an introduced predator to Europe, have seriously affected local densities of birds breeding in coastal areas. I studied the effect of mink removal on breeding ...

Population sizes of large carnivores have increased in Scandinavia during the last century. Increases in predator population sizes can affect prey populations not only through increased mortality, but also through behavioural ...

To understand the ecological effects of large herbivores, it is important to understand foraging behaviour and how this is affected by density. In this experiment, domestic sheep (Ovis aries) were kept at high (80 sheep ...