The ability of captive breeding programs to maintain genetic diversity and fitness has often been questioned. Recent studies suggest that fitness loss can be extremely rapid in various traits, but it is poorly known how captive breeding affects sperm quality and thus male fertility. We studied the potential effects of hatchery-induced selection on traits indicative of semen quality, in four generations ...

In adaptive radiations, ecological opportunity (i.e. niche availability) is considered to be an important driver to increase phenotypic variation, but diversity may also be constrained by historical factors related to colonization events. How do ecological opportunity and post-glacial colonization history affect the phenotypic diversity in a young species lineage? We quantified phenotypic diversity ...

We explore the long-term developments in population biology and life history during the invasion and establishment of the fish species vendace Coregonus albula in a subarctic watercourse by comparing life-history traits and molecular genetic estimates between the source and the colonist population. The two populations exhibited highly contrasting life-history strategies. Relative to the source ...

Lignocellulosic biomass remains a largely untapped source of renewable energy predominantly due to its recalcitrance and an incomplete understanding of how this is overcome in nature. We present here a compositional and comparative analysis of metagenomic data pertaining to a natural biomass-converting ecosystem adapted to austere arctic nutritional conditions, namely the rumen microbiome of Svalbard ...

Pasvikvassdraget har siden 1991 vært gjenstand for omfattende økologiske studier i regi av Ferskvannsøkologisk faggruppe ved Universitetet i Tromsø. Undersøkelsene har særlig vært rettet mot å undersøke effektene av at lagesilda, en fremmed fiskeart for Nord-Norge, kom inn i vassdraget på slutten av 1980-tallet. For å få en grundig forståelse av økologien i vassdraget har studiene også omfattet ...

To what extent top predators - carnivores at the top of food chains - drive or just respond to ecosystem dynamics is a central, but partially unresolved, question in ecology. In this report, we highlight how different research approaches employed in aquatic and terrestrial ecology may have a bearing on how the role of top predators in ecosystems is perceived.

Whirly proteins belong to a small family of proteins with a characteristic secondary structure and a conserved DNA binding domain that is found mainly in angiosperms. At least one member of the Whirly protein family, Whirly1, is dually targeted to the nucleus and to the chloroplasts and it was shown that apart from its initially described function as a transcriptional regulator of nuclear disease ...

The carcass use of juveniles, subadults and adults of the two eagle species in Norway, the White-tailed Eagle (Haliaeetus albicilla) and the Golden Eagle (Aquila chrysaetos) was studied in Finnmark, the northernmost county of Norway for two winters, in 2009 and 2010. Artificial carrion was laid out as bait on four peninsulas, along with automatic digital cameras which took picture on 5-15 minutes ...

Empirical work suggest that long-lived organisms have adopted risk sensitive reproductive strategies where individuals trade the amount of resources spent on reproduction versus survival according to expected future environmental conditions. Earlier studies also suggest that climate affects population dynamics both directly by affecting population vital rates and indirectly through long-term changes ...

Here, we report from the first direct observation of a red fox (Vulpes vulpes) intrusion on an arctic fox (Vulpes lagopus) breeding den from the southern Arctic tundra of Yamal Peninsula, Russia in 2007. At the same time, as a current range retraction of the original inhabitant of the circumpolar tundra zone the arctic fox is going on, the red fox is expanding their range from the south into arctic ...