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Sammendrag

Organisms use circadian rhythms to anticipate and exploit daily environmental oscillations. While circadian rhythms are of clear importance for inhabitants of tropic and temperate latitudes, its role for permanent residents of the polar regions is less well understood. The high Arctic Svalbard ptarmigan shows behavioral rhythmicity in presence of light-dark cycles but is arrhythmic during the polar day and polar night. This has been suggested to be an adaptation to the unique light environment of the Arctic. In this study, we examined regulatory aspects of the circadian control system in the Svalbard ptarmigan by recording core body temperature (Tb) alongside locomotor activity in captive birds under different photoperiods. We show that Tb and activity are rhythmic with a 24-h period under short (SP; L:D 6:18) and long photoperiod (LP; L:D 16:8). Under constant light and constant darkness, rhythmicity in Tb attenuates and activity shows signs of ultradian rhythmicity. Birds under SP also showed a rise in Tb preceding the light-on signal and any rise in activity, which proves that the light-on signal can be anticipated, most likely by a circadian system.

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Sammendrag

The high Arctic archipelago of Svalbard (74°–81° north) experiences extended periods of uninterrupted daylight in summer and uninterrupted night in winter, apparently relaxing the major driver for the evolution of circadian rhythmicity. Svalbard ptarmigan (Lagopus muta hyperborea) is the only year-round resident terrestrial bird species endemic to the high Arctic and is remarkably adapted to the extreme annual variation in environmental conditions. Here, we demonstrate that, although circadian control of behavior disappears rapidly upon transfer to constant light conditions, consistent with the loss of daily activity patterns observed during the polar summer and polar night, Svalbard ptarmigans nonetheless employ a circadian-based mechanism for photoperiodic timekeeping. First, we show the persistence of rhythmic clock gene expression under constant light within the mediobasal hypothalamus and pars tuberalis, the key tissues in the seasonal neuroendocrine cascade. We then employ a “sliding skeleton photoperiod” protocol, revealing that the driving force behind seasonal biology of the Svalbard ptarmigan is rhythmic sensitivity to light, a feature that depends on a functioning circadian rhythm. Hence, the unusual selective pressures of life in the high Arctic have favored decoupling of the circadian clock from organization of daily activity patterns, while preserving its importance for seasonal synchronization.

Sammendrag

På oppdrag av Landbruks- og matdepartementet, har NIBIO gjort en vurdering av forskningen på fire fagområder i reindriften; 1) Kunnskapsgrunnlaget for å vurdere oppnåelsen av bærekraften i reindriften, 2) Klimaendringenes betydning for reindriften, 3) Mulige klimatilpasningsstrategier for reindriften, og 4) Langsiktige konsekvenser av endringer i arealbruk og utbygging for reindriften. Fakta og innspill er hentet inn gjennom litteratursøk, dokumentanalyser og intervjuer med sentrale informanter fra reindriftsnæringen. Effekter av klimaendringer og arealinngrep for reindriften avdekkes gjennom en blanding av biologisk grunnforskning, anvendt forskning i reindriftsområdene, tradisjonell/erfaringsbasert kunnskap og samfunnsforskning. Det må fokuseres på en helhetlig tilnærming for å belyse effekter og sammenhenger mellom ulike drivkrefter på beitegrunnlaget og for å synliggjøre kumulative effekter av arealinngrep på best mulig måte.

Sammendrag

Innføring av obligatorisk individmerking av tamrein i Norge ble vedtatt av Stortinget 13. juni 2019. NIBIO har i denne rapporten belyst hvilke merkemetoder for individmerking som finnes på markedet i dag og hvordan disse egner seg for bruk i reindrifta. Kunnskap om disse og individmerking generelt i næringa, forvaltningen og reindriftsmyndighetene er innhentet gjennom utstrakt kontakt med en rekke informanter. Mulighetene og utfordringene som ligger i individmerking for næring, forvaltning og myndigheter er undersøkt og kartlagt. NIBIO har belyst en del punkter som anbefales for veien videre vedrørende innføring av individmerking i reindriften. NIBIO har også foreslått pilotprosjekter som kan/bør gjennomføres for å forberede reindriften på innføring av individmerking, samt forbedrer dagens løsninger for elektronisk individmerking slik at disse blir driftssikre, kostnadslave, møter næringens behov og nytte og samtidig gir myndigheter og forvaltning ny kunnskap om Norges tamrein...

Sammendrag

Reindeer-train-collisions (RTC) are a challenge for Norwegian society and the northern Norwegian train company Bane NOR with regard to animal welfare, wildlife ecology, animal husbandry, reindeer herding and the working environment for train drivers and employees of Bane NOR. On behalf of Bane NOR the Norwegian Institute of Bioeconomy Research (NIBIO) investigated putative technological solutions to improve RTCs. The study is a result of literature research, interviews with Bane NOR employees, reindeer herders, researchers, companies and road administration project leaders and an analysis of Bane NOR´s own database of animal-train-collisions. The RTC records of the last 11 years (jan 2008 – dec 2018) revealed that prioritizing preventive measures against collisions with female reindeer along the Saltfjellet region during winter, especially during the Arctic night, are most promising. This also happens to be the most damaging time of the year for reindeer herders as they struggle to find damaged animals in the dark. Expensive and timeconsuming search efforts are a major concern with regard to animal welfare. Additionally, damaged animals are often – if at all – found long after the accident and can not be brought into Connection with a specific RTC, i.e. the herders can not claim monetary compensation…….