Keeping cool in the warming Arctic: thermoregulatory behaviour by Svalbard reindeer (Rangifer tarandus platyrhynchus)

In animals with long generation times, evolution of physiological and morphological traits may not be fast enough to keep up with rapid climate warming, but thermoregulatory behaviour can possibly serve as an important buffer mitigating warming effects. In this study, we investigated if the cold-adapted Svalbard reindeer (Rangifer tarandus platyrhynchus (Vrolik, 1829)) used cool bed sites as a thermoregulatory behaviour in the summer. We recorded habitat variables and ground temperature at 371 bed sites with random “control” sites 10 and 100 m distant. Using case-control logistic regression, we found that reindeer selected bed sites on cool substrates (snow and mire), as well as cold, dry ground on days with warm ambient temperatures, while they avoided such sites on cold days. Selection of both cool substrates and cool ground did not depend on age or sex. The study was conducted in an environment where neither predatory threat nor insect harassment influenced bed site selection. Our findings suggest that the thermal landscape is important for habitat selection of cold-adapted Arctic ungulates in summer. Thus, behavioural strategies may be important to mitigate effects of climate change, at least in the short term.

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Reindeer breathe less and save water in the cold

Rangifer ◽

10.7557/2.10.3.864 ◽

1990 ◽

Vol 10 (3) ◽

pp. 243

Author(s):

Kjell J. Nilssen ◽

Arne Rognmo ◽

Arnoldus Schytte Blix

Keyword(s):

Ambient Temperature ◽

Rangifer Tarandus ◽

Treadmill Exercise ◽

Minute Volume ◽

Oxygen Extraction ◽

Running Speed ◽

Ambient Temperatures ◽

Svalbard Reindeer ◽

Respiratory Minute Volume ◽

Low Ambient Temperature

Simultaneous measurements of metabolic rate, respiratory minute volume, respiratory frequency, and oxygen extraction from the inspired air were obtained during treadmill exercise in Svalbard reindeer (Rangifer tarandus platyrhynchus) and Norwegian reindeer (Rangifer tarandus tarandus). The experiments were carried out both in summer and winter at ambient temperatures and running speeds ranging from +12 to -30 °C and 3.7 to 9.0 knvh1, respectively. We found that respiratory minute volume was generally lower in summer than in winter for a similar ambient temperature, and also that respiratory minute volume was reduced at low ambient temperature both in summer and winter. The change in respiratory minute volume was inversely related to oxygen extraction, the latter being at its highest at the lowest ambient temperature and running speed in summer. Reduction of respiratory minute volume, and hence respiratory water loss, at low ambient temperature is likely to contribute significantly to the survival of these species, particularly in winter when the animals can only replace body water with snow at low temperature.

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Summer habitat selection of reindeer (Rangifer tarandus) governs on the unprotected forest and human interface in China

Ekológia (Bratislava) ◽

10.2478/eko-2018-0011 ◽

2018 ◽

Vol 37 (2) ◽

pp. 112-121

Author(s):

Jing Wang ◽

Peng Wang ◽

Achyut Aryal ◽

Xiuxiang Meng ◽

Robert B. Weladji

Keyword(s):

Habitat Selection ◽

Rangifer Tarandus ◽

Principal Component ◽

Arctic Region ◽

Forest Area ◽

Slope Position ◽

Anthropogenic Factors ◽

Selection Strategy ◽

Selection Of ◽

Habitat Variables

AbstractThe habitat selection by animals depends on different environmental and anthropogenic factors such as the season, climate, and the life cycle stage. Here, we have presented the summer habitat selection strategy of reindeer (Rangifer tarandus) in the unprotected forest area from the northern arctic region of China. In summer 2012, we investigated a total of 72 used and 162 non-used plots in the reindeer habitat to record habitat variables. We found that the reindeer used significantly higher altitude, arbour availability, and vegetation cover area as compared to the non-used habitat variables. Principal component analysis (PCA) showed that six principal components (68.5%) were mainly responsible for the summer habitat selection of reindeer such as the slope position, concealment, anthropogenic dispersion, arbour species, distance from the anthropogenic disturbance area (> 1000 m) and water quality (Wilks’ Lambda = 0.12; P = 0.0001). The local people are largely dependent on forest product resource in these regions, such as bees herding, collecting wild vegetables, hunting, poaching, and grazing. These activities highly influenced the reindeer habitat and its behaviours. This study thus confirmed that reindeers are forced to choose poor habitat in unprotected forest area with high human disturbance or interference. These factors should be considered by the concerned authority or agency to manage reindeer population in the wild.

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Svalbard reindeer (Rangifer tarandus platyrhynchus) antler characteristics reflecting the local environmental conditions

Folia Oecologica ◽

10.2478/foecol-2019-0003 ◽

2019 ◽

Vol 46 (1) ◽

pp. 16-23

Author(s):

Jan Kavan ◽

Veronika Anděrová

Keyword(s):

Environmental Conditions ◽

Rangifer Tarandus ◽

Well Being ◽

Climatic Conditions ◽

High Mountain ◽

Atmospheric Conditions ◽

Individual Subject ◽

Svalbard Reindeer ◽

Invasive Method ◽

Antler Size

AbstractA new non-invasive method based on picture analysis was used to estimate the conditions in Svalbard reindeer populations. The well-being of an individual subject is often expressed through visual indices. Two distinct reindeer populations were compared based on their antler parameters. Relative antler size and number of tines are variables supposed to reflect correspondingly the environmental conditions of sedentary populations within the growing season. The occurrence areas of two studied populations are distinctly isolated – separated with high mountain ridges, glaciers and fjords. The population in Petuniabukta occupies a sparsely vegetated region with harsh climatic conditions, whereas Skansbukta represents an area with continuous tundra vegetation cover, milder climatic conditions and, consequently, also a longer vegetation season. These environmental factors probably caused significant differences in the relative antler size and number of tines in the studied species. The Skansbukta population exhibited a larger relative antler size and higher number of tines than the population in Petuniabukta (both parameters differed significantly, p < 0.01). This difference reflects concisely the different environmental conditions of both locations. A comparison of Skansbukta population antler characteristics between years 2017 and 2018 did not reveal significant changes, most probably due to very similar atmospheric conditions in these two years (in terms of air temperature).

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Energy expenditure of free-living reindeer estimated by the doubly labelled water method

Rangifer ◽

10.7557/2.20.4.1516 ◽

2000 ◽

Vol 20 (2-3) ◽

pp. 211 ◽

Cited By ~ 10

Author(s):

Geir Gotaas ◽

Eric Milne ◽

Paul Haggarty ◽

Nicholas J.C. Tyler

Keyword(s):

Energy Expenditure ◽

Rangifer Tarandus ◽

Water Flux ◽

Co2 Production ◽

Wild Ungulates ◽

Free Living ◽

Doubly Labelled Water ◽

Svalbard Reindeer ◽

Mountain Pasture ◽

The Mean

The doubly labelled water (DLW) method was used to measure total energy expenditure (TEE) in three male reindeer (Rangifer tarandus tarandus) aged 22 months in winter (February) while the animals were living unrestricted at natural mountain pasture in northern Norway (69°20'N). The concentrations of 2H and l8O were measured in water extracted from samples of faeces collecred from the animals 0.4 and 11.2 days after injection of the isotopes. Calculated rates of water flux and CO2-production were adjusted to compensate for estimated losses of 2H in faecal solids and in methane produced by microbial fermentation of forage in the rumen. The mean specific TEE in the three animals was 3.057 W.kg-1 (range 2.436 - 3.728 W.kg1). This value is 64% higher than TEE measured by the DLW method in four captive, non-pregnant adult female reindeer in winter and probably mainly reflects higher levels of locomotor activity in the free-living animals. Previous estimates of TEE in free-living Rangifer in winter based on factorial models range from 3.038 W.kg-1 in female woodland caribou (R. t. caribou) to 1.813 W.kg-1 in female Svalbard reindeer (R. t. platyrhynchus). Thus, it seems that existing factorial models are unlikely to overestimate TEE in reindeer/caribou: they may, instead, be unduly conservative. While the present study serves as a general validation of the factorial approach, we suggest that the route to progress in the understanding of field energetics in wild ungulates is via application of the DLW method.

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Low-Temperature Activity of Lactic Streptococci Isolated from Cultured Buttermilk

Journal of Food Protection ◽

10.4315/0362-028x-45.13.1208 ◽

1982 ◽

Vol 45 (13) ◽

pp. 1208-1211 ◽

Cited By ~ 5

Author(s):

STEVEN L. HOGARTY ◽

JOSEPH F. FRANK

Keyword(s):

Low Temperature ◽

Skim Milk ◽

Potential Effect ◽

Starter Cultures ◽

Streptococcus Lactis ◽

Streptococcus Cremoris ◽

Generation Times ◽

Significant Difference ◽

Selection Of

Psychrotrophic and mesophilic lactic streptococci were isolated from commercial cultured buttermilk to determine their potential effect on the quality of this product. These isolates consisted primarily of Streptococcus lactis subsp. diacetylactis, with S. lactis, Streptococcus cremoris, and Leuconostoc spp. also being present. Psychrotrophic isolates of S. lactis subsp. diacetylactis were compared to mesophilic isolates in regard to their ability to grow and reduce diacetyl in acidified milk (pH 4.7) incubated at 7°C. There was no significant difference detected in the ability of the two groups to reduce diacetyl (P<.05). The mesophilic isolates grew more rapidly in acidified refrigerated milk than did the psychrotrophs, indicating that the psychrotrophic isolates were more acid sensitive. The psychrotrophic isolates exhibited generation times of 9 to 11 h when grown in skim milk (pH 6.7) at 7°C. Both psychrotrophic and mesophilic strains of S. lactis subsp. diacetylactis could rapidly reduce diacetyl in refrigerated acidified milk. The results of this study suggest that procedures for selection of starter cultures for buttermilk manufacture should be improved.

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Use of climatic data to assess the effect of insect harassment on the autumn weight of reindeer (Rangifer tarandus) calves

Journal of Zoology ◽

10.1017/s0952836903003510 ◽

2006 ◽

Vol 260 (1) ◽

pp. 79-85 ◽

Cited By ~ 53

Author(s):

Robert B. Weladji ◽

Øystein Holand ◽

Trygve Almøy

Keyword(s):

Rangifer Tarandus ◽

Climatic Data ◽

Insect Harassment

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Hydrogen Assisted Fracture of Type 316 Stainless Steel at Sub-Ambient Temperature

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2008-61240 ◽

2008 ◽

Cited By ~ 1

Author(s):

C. San Marchi ◽

B. P. Somerday ◽

X. Tang ◽

G. H. Schiroky

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steels ◽

Hydrogen Gas ◽

Ambient Temperatures ◽

316 Stainless Steel ◽

Properties Of Materials ◽

Effects Of Temperature ◽

High Concentrations ◽

Selection Of ◽

Assisted Fracture

Applications requiring the containment and transport of hydrogen gas at pressures greater than 70 MPa are anticipated in the evolving hydrogen economy infrastructure. Since hydrogen is known to alter the mechanical properties of materials, data are needed to guide the selection of materials for structural components. Type 316 austenitic stainless steels are often considered one of the best choices for resistance to hydrogen-assisted fracture; however, at sub-ambient temperatures some alloy compositions of type 316 stainless steel can become more susceptible to hydrogen-assisted fracture than others. In this study, we report the tensile properties of two heats of type 316 stainless steel, emphasizing the effects of temperature and high concentrations of internal hydrogen on these properties.

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