Show simple item record

dc.contributor.authorArnold, Walter
dc.contributor.authorRuf, Thomas
dc.contributor.authorLoe, Leif Egil
dc.contributor.authorIrvine, R. Justin
dc.contributor.authorRopstad, Erik
dc.contributor.authorVeiberg, Vebjørn
dc.contributor.authorAlbon, Steve D.
dc.description.abstractStudies of locomotor activity in Svalbard reindeer reported the temporary absence of diel rhythms under Arctic photic conditions. However, using Lomb-Scargle periodogram analyses with high statistical power we found diel or circadian rhythmicity throughout the entire year in measures of behaviour, temperature in the rumen and heart rate in free-living Svalbard reindeer. Significant diel rhythmicity was only lacking during some of the 15-day intervals analysed in the less frequently measured heart rate. During Polar Night these rhythms were free-running and attenuated. During continual daylight in summer, rhythms where entrained to 24 hours corresponding with the daily variation in the intensity of solar radiation, but attenuated when continuous daylight coincided with the period of growing forage. Diel rhythmicity was reduced during this short period of peak foraging activity, which coincided with peak heart rate and temperature in the rumen, most likely to facilitate fattening when food is abundant. For the rest of the year, heart rate and temperature showed the most pronounced and long-lasting suppression ever found in ungulates. The profound seasonal changes in foraging, metabolic activity, and power of diel and circadian rhythmicity of Svalbard reindeer can be viewed as adaptations to the extreme living conditions in the High Arctic.nb_NO
dc.rightsNavngivelse 4.0 Internasjonal*
dc.titleCircadian rhythmicity persists through the Polar night and midnight sun in Svalbard reindeernb_NO
dc.title.alternativeCircadian rhythmicity persists through the Polar night and midnight sun in Svalbard reindeernb_NO
dc.typeJournal articlenb_NO
dc.typePeer reviewednb_NO
dc.rights.holder© The Author(s) 2018nb_NO
dc.subject.nsiVDP::Zoologiske og botaniske fag: 480nb_NO
dc.subject.nsiVDP::Zoology and botany: 480nb_NO
dc.source.journalScientific Reportsnb_NO
dc.relation.projectNorges forskningsråd: 223257nb_NO
dc.relation.projectEgen institusjon: Norwegian institute for nature research (NINA)nb_NO
cristin.unitnameAvdeling for terrestrisk økologi

Files in this item


This item appears in the following Collection(s)

Show simple item record

Navngivelse 4.0 Internasjonal
Except where otherwise noted, this item's license is described as Navngivelse 4.0 Internasjonal