scholarly journals Do seasonal changes in Svalbard reindeer fur have relevance for heat transfer?

Rangifer ◽  
2002 ◽  
Vol 22 (2) ◽  
pp. 133 ◽  
Author(s):  
Christine Cuyler ◽  
Nils A. Øritsland
Keyword(s):  
Heat Transfer ◽  
Seasonal Changes ◽  
Rangifer Tarandus ◽  
Direct Relationship ◽  
Physical Characteristics ◽  
Hair Density ◽  
Wind Resistance ◽  
Svalbard Reindeer ◽  
Hair Roots ◽  
Main Determinants

Physical characteristics of Svalbard reindeer (Rangifer tarandus platyrhynchus) fur samples were examined with respect to season. A total of 33 dorsal fur sections including adults and calves were investigated. A direct relationship between hair density and heat transfer was not observed, and optimal hair density may depend on an interaction with other fur characteristics. Seasonal changes in fur length and depth were inversely proportional to, and appear to be the main determinants of, seasonal changes in calm air conductance. Fur length and depth, however did not explain the exceptional wind resistance of Svalbard reindeer fur. Since wind has little effect on heat transfer through Svalbard reindeer fur regardless of season or animal age, fur characteristics, which change are not likely critical. Instead, constant physical characteristics, which trap still-air within the fur and resist wind compaction and penetration, are probably responsible. These could include hair stiffness, the crimped wave, hollow hairs, intertwining distal tips and the fine wool fuzz about the hair roots. The extent and means are not well understood at present.

Seasonal changes in T3, FT4, and cortisol in free-ranging svalbard reindeer (Rangifer tarandus platyrhynchus)

1985 ◽  
Vol 59 (2) ◽  
pp. 210-213 ◽  
Author(s):  
Kjell J. Nilssen ◽  
Karstein Bye ◽  
Johan A. Sundsfjord ◽  
Arnoldus Schytte Blix
Keyword(s):  
Seasonal Changes ◽  
Rangifer Tarandus ◽  
Svalbard Reindeer ◽  
Free Ranging

scholarly journals Effect of wind on Svalbard reindeer fur insulation

Rangifer ◽  
2002 ◽  
Vol 22 (1) ◽  
pp. 93 ◽  
Author(s):  
Christine Cuyler ◽  
Nils A. Øritsland
Keyword(s):  
Heat Transfer ◽  
Wind Tunnel ◽  
Heat Loss ◽  
Wind Velocity ◽  
Rangifer Tarandus ◽  
Svalbard Reindeer ◽  
Significant Difference ◽  
Wind Velocities ◽  
Autumn And Winter

The heat transfer through Svalbard reindeer (Rangifer tarandus platyrhynchus) fur samples was studied with respect to wind velocity, season and animal age. A total of 33 dorsal fur sections were investigated using a wind tunnel. Insulation varied with season (calving, summer, autumn and winter). At zero wind velocity, fur insulation was significantly different between seasons for both calf and adult fur samples. At the same time, there was no significant difference between calf and adult insulation for the summer, autumn and winter seasons. Calf fur insulated as well as adult fur. Winter insulation of Svalbard reindeer was approximately 3 times that of summer. Increasing wind veloci¬ty increased heat loss, however, the increase was not dramatic. When wind coefficients (slope) of the heat transfer regression lines were compared, between season and between calf and adult, no significant differences were reported. All fur samples showed similar increases in heat transfer for wind velocities between 0 and 10 m.s-1. The conductance of winter fur of Svalbard reindeer was almost half that of caribou fur. Also, conductance was not as greatly influenced by wind as caribou fur

Interisland movements of Peary caribou (Rangifer tarandus pearyi) on western Queen Elizabeth Islands, Arctic Canada

1977 ◽  
Vol 55 (6) ◽  
pp. 1029-1037 ◽  
Author(s):  
Frank L. Miller ◽  
Richard H. Russell ◽  
Anne Gunn
Keyword(s):  
Seasonal Changes ◽  
Horizontal Plane ◽  
Rangifer Tarandus ◽  
Maximum Distance ◽  
Arctic Canada ◽  
Complete Evaluation ◽  
Spray Method ◽  
Annual Range ◽  
Vector Sum

To verify that Peary caribou were making seasonal interisland movements, we used an aerial dye-spray method. In April 1974, about 230 caribou were dye-marked green, and about 200 were marked red on Prince Patrick and Eglinton islands respectively. Aerial searches in June and July 1974 located 41 sightings of dye-marked animals. Of animals marked on Prince Patrick Island 4 were seen on Melville Island, 3 on Eglinton Island, and 16 on Prince Patrick. Of sightings of animals marked on Eglinton Island, there were 6 on Prince Patrick Island and 12 on Eglinton. Maximum distance travelled (vector sum on horizontal plane) by marked caribou was 450 km, from Prince Patrick Island to eastern Melville Island. The study indicates that high proportions of the caribou population seasonally range over two or more islands of the western Queen Elizabeth Group. Therefore, complete evaluation of annual range requirements on an island basis should take into consideration seasonal changes in numbers of caribou that are due to interisland movements.

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

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).

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

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 211 ◽  
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&deg;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.

THE EFFECT OF WIND AND MOISTURE ON HEAT LOSS THROUGH THE FUR OF NEWBORN CARIBOU

1960 ◽  
Vol 38 (4) ◽  
pp. 679-688 ◽  
Author(s):  
C. P. Lentz ◽  
J. S. Hart
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Loss ◽  
Physical Characteristics ◽  
Air Velocity ◽  
Direction Parallel ◽  
Air Movement

The effects of air velocity and direction and of wetness on rate of heat transfer were studied in tests with samples of fur from five caribou calves. The rate of heat transfer through this fur increased by a factor of two to three with increase in air velocity from a negligible level (natural convection) to 23 m/second (direction parallel to sample). The effect of air velocity varied markedly (up to ±50% at 23 m/second) with inclination of the sample to the direction of air movement. Spraying water on the fur increased its rate of heat transfer markedly; addition of water equivalent to 10–12% of the volume of the fur doubled the rate of heat transfer. Other factors, such as erectness of the fur, direction of the hairs or "grain" of the fur with respect to the direction of air movement, and wetness of the skin also affected heat transfer. Differences between samples were large and did not appear to depend directly on the physical characteristics measured.

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