Seasonal and Interannual Dietary Variation During Winter in Female Svalbard Reindeer (Rangifer Tarandus Platyrhynchus)

Abstract

We investigated dietary variation during three winters in female Svalbard reindeer (Rangifer tarandus platyrhynchus) on the basis of rumen samples from animals culled in early and late winter during 2000-2002. The winter diet was compared to a late summer diet on the basis of samples from 1999, with variations in dietary composition in early and late winter among years also investigated. We conducted our assessment by identifying plant fragments in rumen samples using a point identification method. The effects of season and year on dietary composition of females were tested using non-parametric multifactorial MANOVA. During early winter, the diet seemed to be a function of both plant availability and plant quality, with the latter also highly important for the summer diet. During late winter, restricted forage availability due to snow cover seemed to have influenced dietary composition. We also found dietary variation among years both in early and late winter. We hypothesize that climatic effects previously found on the growth rate of Svalbard reindeer populations may be mediated through interannual variation in their diet where increased summer precipitation and winter rain may affect the dietary composition through decreased availability of forage biomass.

Can root-associated fungi mediate the impact of abiotic conditions on the growth of a High Arctic herb?

“…However, it is based on remote measurements of Earth's surface reflectance, and therefore takes into consideration only aboveground changes in foliage. In these methods plants' below-ground productivity and biomass are omitted, probably resulting in underestimation of the overall impact of increased temperatures on plants, such as B. vivipara , which is an ubiquitous species in the Arctic and essential food source for ptarmigans68 , geese69 and reindeer70 . Temperature had a direct opposite effect of similar magnitude on LL and RV (-0.34 vs 0.29, respectively), additionally strengthened by indirect fungal effects, which suggests that NDVI can easily underestimate the impact of warming on overall plant biomass and misjudge understanding of carbon stocks dynamics.…”

Annual ring growth of a widespread high arctic shrub reflects past fluctuations in community‐level plant biomass

“…Given that S. polaris forms a major component of the diet of Svalbard reindeer (Bjørkvoll et al, 2009;Van der Wal et al, 2000), it could well be that herbivory influences ring growth in this dwarf shrub, with possible carry-over effects. Simulated grazing was shown to reduce leaf biomass production in the following summer (Skarpe & Van der Wal, 2002).…”

“…dempstercountry.org/) and is the most widespread shrub species found across Svalbard, in habitats ranging from arctic meadow to polar desert (https://svalbardflora.no/, Nakatsubo, Fujiyoshi, Yoshitake, Koizumi, & Uchida, 2010;Rønning, 1996). Its abundance and high digestibility make it an important food resource for herbivores, especially reindeer (Bjørkvoll, Pedersen, Hytteborn, Jónsdóttir, & Langvatn, 2009;Van der Wal et al, 2000). The species has been reported to live for many decades, with a mean plant age of around 40 years (Buchwal et al, 2013;Owczarek & Opała, 2016).…”

Annual variability of heavy metal content in Svalbard reindeer faeces as a result of dietary preferences

“…Because of their high population, which is due to a lack of natural enemies, reindeer occupy all areas of Svalbard not covered by glaciers. The local reindeer populations are considered non-migratory, as a result of which they consume vegetation within a relatively small area (Bjørkvoll et al 2009 ; Hansen et al 2010 ). During the short, three-month vegetation period, Svalbard reindeer have to eat enough forage to survive and build additional reserves of energy for the winter season (Bjørkvoll et al 2009 ; Reimers 1982 ; Tyler 1986 ).…”

“…The local reindeer populations are considered non-migratory, as a result of which they consume vegetation within a relatively small area (Bjørkvoll et al 2009 ; Hansen et al 2010 ). During the short, three-month vegetation period, Svalbard reindeer have to eat enough forage to survive and build additional reserves of energy for the winter season (Bjørkvoll et al 2009 ; Reimers 1982 ; Tyler 1986 ). However, the long winter usually results in the premature depletion of body reserves and a constant search for food under the snow layer (Bjørkvoll et al 2009 ; Tyler 1986 ).…”