Colony nesting is thought to be an example of the selfish herd strategy, where aggregating behaviour may be an evolutionary adaptation to reduce the risk of predation. The common eider (Somateria mollissima) is a ground nesting sea bird susceptible to high nest predation rates through the nesting period. They often nest in groups, yet some also choose to nest solitarily. I examined whether group ...

Tundra arthropods have considerable ecological importance as a food source for several bird species that are reproducing in the Arctic. The actual arthropod taxa comprising the chick diet are however rarely known, complicating assessments of ecological interactions. In this study, I identified the nestling diet of Svalbard snow bunting (Plectrophenax nivalis) for the first time. Faecal samples of ...

The post-weaning fast of hooded seal pups (Cystophora cristata) is not well understood. What energy sources are being used? How is water balance maintained? How are these mechanisms balanced with thermoregulation? This study aims to answer some questions on the physiological mechanisms in place to assist an Arctic seal pup in the early stages of their life with no source of food or freshwater. ...

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 ...

Seasonality affects growing patterns of vegetation and habitat use by herbivores. Short growing seasons make plants grow quickly through phenological stages which alters their nutrient levels and thus habitat use of herbivores that depend on energy assimilation in summer. Selective foraging that increases intake of high-quality forage can be highly advantageous and is usually a trade-off between ...

Pasvikvassdraget ble tidlig på 1990-tallet utsatt for en invasjon av lagesild fra Enaresjøen i Finland. I 2009 ble det gjennomført et eksperiment med utsetting av 1500 ørret i Ruskebukta i øvre del av vassdraget, for å undersøke ørretens egnethet til biokontroll av den invaderende lagesilda. For at biokontroll med fiskespisende ørret skal være vellykket er det viktig å ha god kjennskap til økosystemet ...

Reindeer (Rangifer tarandus) live in the Arctic and have evolved special adaptations to cope with hard environmental conditions. Nasal heat exchange (NHE), which is an efficient heat and water exchange mechanism to combat loss of energy, is well documented in adult reindeer (e.g. Blix and Johnsen (1983), Johnsen 1988). However, it is not known if this mechanism is fully developed from birth and if ...

Bilberry (Vaccinium myrtillus L.) is a dwarf shrub and its berries are rich source of nutrients, fibers and vitamins. Bilberry consumption has been shown to positively correlated with improvement of human health. Anthocyanins and proanthocyanidins (PAs) are important secondary metabolites that are synthetized in plants via flavonoid biosynthesis pathway. PAs also have anti-cancer, anti-inflammatory ...

The introduction of new hosts into new habitats can bring along hitchhiking parasites, i.e. parasites being introduced with the host. This in particular can be an important dispersal mechanism for autogenic parasites that are otherwise restricted by the natural movement of their fish hosts. In this study, the effect of a local host introduction on the parasite communities of three-spined sticklebacks ...

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 ...