Abstract Reindeer management in the Fennoscandian area is currently facing challenges such as degradation of winter pastures, which may lead in the most severely affected areas to a concurrent decline in reindeer herd productivity. The use of often expensive supplementary feeding to prevent production losses has increased the demand for studies on the physiological effects of nutritional restriction and supplementary feeding. The knowledge obtained from such studies could be used, for example, to monitor the condition of reindeer in studies assessing herd productivity levels in different pasture conditions and management systems or sustainable use of pasture resources. In this thesis, the effects of season, year, pasture area, body mass, pregnancy and other extrinsic and intrinsic factors on the variation of blood chemical constituents of reindeer were studied in free-ranging animals under natural foraging conditions. The studied blood chemical constituents covered a wide range of parameters related to protein, carbohydrate, lipid and mineral metabolism. The same blood chemical constituents were studied in captive reindeer under defined feeding conditions, allowing an analysis of the effects of dietary protein, energy and mineral intake on the selected blood constituents and their comparison to a conventional measure of the animals' condition, live body mass. According to the results, free-ranging reindeer showed great variation in the concentrations of blood chemical constituents compared to the reference values of domesticated ruminants. Intrinsic factors such as body mass, pregnancy and age had only a minor influence on the variation of the studied parameters, whereas extrinsic factors such as season, year and pasture area, which were characterized by marked changes in environmental and nutritional conditions, explained the majority of the variation. The results obtained from captive animals in defined feeding conditions and from free-ranging animals foraging on natural pastures led to the conclusion that blood total proteins, albumin, urea, creatinine, urea:creatinine ratio, magnesium, inorganic phosphate and, to a lesser extent, globulins and albumin:globulin ratio responded to the changes in feed quality and availability and were the most suitable blood constituents to be used as nutritional biomarkers for reindeer.

Mountain caribou (Rangifer tarandus caribou) are endangered in British Columbia and motorized backcountry recreation has been identified as a potential threat to their persistence. My objective was to test if fecal glucocorticoids (GCs), indicative of physiological effects of ecological stress in wildlife, could be used as a non-invasive tool to quantify stress response in free-ranging caribou exposed to motorized recreation. I validated an enzyme-linked immunosorbent assay (ELISA) to measure concentration of fecal GCs for R. tarandus using an adrenocorticotropic hormone (ACTH) challenge experiment on captive reindeer exposed to extreme variation in winter weather. Female reindeer expressed elevated fecal GCs 9-11 hrs after ACTH injection. Males showed no detectable increase, perhaps due to underdosing. Fecal GCs varied markedly in both sexes in response to natural variation in weather. Overall, my results indicated fecal assays can be used to track biologically meaningful changes in adrenal activity in R.tarandus. I investigated the effects of motorized recreation on stress hormone production by measuring GCs in feces of mountain caribou exposed to snowmobile and heli-ski activity. Concentrations of fecal GCs in snowmobile and heli-ski areas were higher than those measured from caribou in areas where motorized recreation was not allowed. Caribou sampled up to 4km. 8km and I0 km distant from snowmobile activity showed elevated fecal GCs when compared to those sampled further from snowmobile activity areas. Other variables with a significant effect on fecal GCs included reproductive state, snow, aspect. minimum ambient temperature, and daily temperature range. My study indicates that measurement of fecal GCs provides a useful, noninvasive approach in the evaluation of physiological effects of environment, reproductive state, and human-induced stressors on free-ranging mountain caribou. Although research on many species indicates that chronically elevated GCs carry a variety of physiological costs, more study is needed to know whether GCs can be used as an index of human impact on population health or trend. / Forestry, Faculty of / Graduate

Global and local climate patterns may affect barren-ground caribou (Rangifer tarandus groenlandicus) populations. I predicted global climate changes to be correlated with periods of population decline, and local changes to be more pronounced on the habitat of caribou with a declining population. In chapter 1, the Arctic Oscillation (AO), changes in normalized difference vegetation index and phenology were used as measures of global and local climate. In chapter 2 environmental variables and caribou presence points were used to build Maxent habitat models. There was no consistent correlation with the positive AO phase and periods of population decline, or phenology trends and the habitat of caribou with a declining population. Maxent models underestimated the amount of suitable habitat spatially and failed to model suitable habitat temporally. This thesis is the first to look at a range of density-independent variables over a long time period and model suitable habitat for multiple herds.

Environmental enrichment is commonly used to improve the welfare of captive animals by offering options to increase behavioural diversity and normal behaviour patterns. The aim of this study was to assess if environmental enrichment has a positive effect on a group of four zoo-housed reindeer, Rangifer tarandus. Three types of environmental enrichment were used: food enrichment, olfactory enrichment, and tactile enrichment, with a spontaneous rotation to prevent habituation. Following a baseline period of ten days without enrichment, the animals’ behaviour was monitored for four months with enrichment. All behaviours shown by the reindeer during the study were categorized into locomotory behaviour, feeding behaviour, passive behaviour, social interactions, and behaviour towards enrichment. The overall level of activity of the reindeer almost doubled between the baseline period (40.8%) and the enrichment period (75.3%), with a significant increase in feeding behaviour (p < 0.001) and a significant decrease in passive behaviour (p < 0.001). Food enrichment had the strongest impact on the reindeer out of the three types of enrichment presented. Even though the reindeer showed a continuous interest towards tactile enrichment, it was low compared to the interest shown towards food enrichment. They also showed little interest in olfactory enrichment. Neophobia may explain the lack of interest by the reindeer to certain types of enrichment that were novel to them. Overall, the presentation of environmental enrichment made the behaviour of the captive reindeer clearly more similar to the behaviour of wild reindeer.

The population trajectory of woodland caribou (Rangifer tarandus caribou) in Newfoundland is currently determined by low calf survival due to high predation rates during the first 6-8 weeks after parturition. Most caribou in Newfoundland congregate and give birth in open calving grounds; consequently, in order to investigate predator-prey interactions, design research, and develop mitigation strategies, the geographic extent of the caribou calving grounds must be properly identified. We used VHF telemetry locations of caribou calves, collected from 2003-2010, to determine the spatial and temporal extent of caribou calving grounds in three study areas in Newfoundland. We put GPS collars on 47 black bears (Ursus americanus) in 3 caribou ranges where bears are having a significant impact on caribou recruitment by preying on calves during the calving season. Bear movements were greatest during the calving season, potentially increasing encounters with calves. Some bears migrated to the calving grounds just prior to caribou parturition, indicating deliberate broad-scale selection of areas of high calf density. Bears displayed interannual fidelity to calving ground usage patterns during the calving season, with some bears using the calving grounds every year, while others did not. We estimated the probability of a bear spending time in the calving grounds during the calving season as a function of the bear’s sex and mean distance to the calving grounds with logistic regression. We found that as distance increased, the odds of a bear spending time in the calving grounds decreased, and that at any given distance the odds were greater for male bears than for female bears. Our results indicate that some bears in Newfoundland are likely caribou calf predators, while others are not, and that the sex and broad-scale distribution of bears influenced the probability of a bear participating in calf predation during the calving season. The probability distribution of calf-visiting bears could be used to develop management practices to mitigate the impact of bear predation on declining caribou herds in Newfoundland.

The fact that large herbivores, such as Rangifer tarandus, play a part in shaping its environment through grazing and trampling of the ground is widely acknowledged today, as well as that these factors have the potential of affecting regional patterns and even global climate. This study investigated whether a considerable increase in grazing by R. tarandus for 25 years resulted in any measurable effects on the diversity of plant species in tundra vegetation. We evaluated if any differences in species composition could be found, based on differences in grazing pressure and productivity of the soil. The effect of difference in grazing pressure was studied through analysis of vegetation at 30 sites, each site comparing two different classes of grazing pressure separated by a fence, and pellets from R. tarandus were counted along transects. We did not find any evidence that the difference in grazing pressure affected the species composition on either side of the fence, depending on the site. The lack of difference in plant species composition may be explained by insufficient differences in abundance of R. tarandus, insufficient time passed since the change in grazing pressure, or varying grazing seasons at the sites on either side of the fence.

vegetation and soil carbon-and nitrogen cycles in a grazing area through food selection, consumption, fertilization, and trampling. There have been discussions on how reindeer grazing, plant communities, and different ecosystems relate to each other and how the management of protected areas should proceed based on various laws, recommendations, and perspectives. The purpose of this study is to examine the impact of reindeer grazing on biodiversity in northern Scandinavia and thus be able to support these discussions. Inventory data was collected in 1995 on both sides of the fence that demarcates Norway from Malla National Park in Finland. At the time of the inventory, reindeer husbandry had been prohibited on the Finnish side of the fence for several decades, creating a difference in grazing pressure between the inventory areas. A statistical comparison was made between the number of plant species for six different functional plant groups divided into four different soil moisture types between the two countries, as well as a comparison of the number of reindeer droppings per study area in each country to quantify the difference in grazing pressure. The results show that there were more grass species in meadow areas and more reindeer droppings on the Norwegian side. I found no significant difference for the other functional plant groups or for the grasses in the other soil moisture types. Based on these results, I conclude that reindeer may increase the number of grass species in meadow areas.

Bien que les infections à Besnoitia tarandi sont documentées chez l’espèce Rangifer sp. depuis 1922, les données récoltées sur l’écologie et la distribution de cette parasitose demeurent rares. Les objectifs de cette étude ont donc été (i) d’identifier le meilleur tissu à échantillonner pour détecter les infections à Besnoitia tarandi dans les populations de caribous, (ii) de calculer la sensibilité et la spécificité de l’examen visuel comparativement à l’examen microscopique et (iii) d’identifier les facteurs de risques intrinsèques et extrinsèques associés à cette parasitose afin (iv) de comparer la prévalence et la densité des kystes parasitaires entre certains troupeaux. Nos résultats suggèrent que l'examen microscopique du derme superficiel d’une section de peau provenant du tiers moyen antérieur du métatarse devrait être privilégié pour dépister les infections par B. tarandi et en évaluer l'intensité. L’examen microscopique est également un outil très sensible comparativement à l’examen visuel des kystes parasitaires. Besnoitia tarandi, qui semble être absent du Groenland, a été observé dans environ un tiers des caribous nord-américains. Une variation saisonnière de prévalence et d'intensité de B. tarandi a été détectée; le parasite étant plus abondant chez cet hôte intermédiaire durant la période de l'automne/hiver comparativement à celle du printemps/été. Cet effet saisonnier pourrait être associé à une augmentation de l'abondance du parasite suite à la saison des insectes (i.e. été), supportant ainsi le rôle présumé des arthropodes piqueurs comme vecteurs de la maladie. Cette différence saisonnière pourrait aussi être expliquée par la diminution de la charge parasitaire par le système immunitaire et/ou par un taux de survie inférieur des animaux les plus parasités durant la saison froide. Les niveaux d'infection étaient légèrement plus élevés chez les mâles que chez les femelles, ce qui suggère soit une diminution du taux de mortalité, soit une exposition accrue ou une plus grande susceptibilité au parasite des mâles en comparaison aux femelles. La densité d’infection supérieure dans le troupeau Rivière-aux-Feuilles (Nunavik) suggère des niveaux d'exposition au parasite plus élevés et/ou une diminution des niveaux de résistance de ces caribous à ce protozoaire. Les résultats de cette étude démontrent que B. tarandi peut réduire les chances de survie des caribous infectés. Il sera donc important de continuer à surveiller les infections à B. tarandi surtout en cette période de changements climatiques. / Although Besnoitia tarandi has been described in Rangifer sp. for over 80 years, understanding of its ecology and distribution is still relatively limited. The objectives of this study were (i) to determine the anatomical sampling site that enhances detection of Besnoitia tarandi infections in caribou populations; (ii) to evaluate the relative sensitivity and specificity of the in situ macroscopic assessment for diagnosis of besnoitiosis compared to the microscopic evaluation; and (iii) to identify potential risks factors associated with the prevalence and intensity of B. tarandi cysts and compare these across different populations. Our results suggest that calculating the number of cysts present in the superficial dermis of a skin section of the anterior mid-third of the metatarsus region by microscopic examination should be favored in order to monitor the presence and intensity of B. tarandi infections. Macroscopic assessment of B. tarandi cysts was not a sensitive method compared to that of a microscopic analysis. Besnoitia tarandi seems to be absent from Greenland but has been encountered in approximately one third of North-American caribou. A seasonal effect was noticed in the prevalence and intensity of B. tarandi infections; the parasite being more abundant in caribou sampled during the fall/winter period compared to the spring/summer period. This effect could reflect the increase abundance of B. tarandi following the end of the insect season (i.e. summer), supporting the role of arthropods as vectors of transmission. Reduction of the parasite burden by the immune system and/or a lower winter survival rate of severely infected caribou could explain the seasonal difference. The slightly higher prevalence in males suggests lower mortality rate, higher exposure and/or higher susceptibility to the parasite in infected males when compared to infected females. The apparent higher density of infection by B. tarandi in the Rivière-aux-Feuilles herd (Nunavik, Québec) suggests either higher exposure to the parasite or reduced resistance of caribou from this herd. The findings of this study suggest that infection by B. tarandi might reduce survival of individual animals; hence, the dynamic between this parasite and its hosts is worth further investigation, especially in these days of changing Arctic environment.

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