Wild Reindeer In Norway Research Articles

Assessing freedom from chronic wasting disease in semi-domesticated reindeer in Norway and Sweden

Establishing freedom from disease is a key component of surveillance and may have direct consequences for trade and economy. Transboundary populations pose challenges in terms of variable legislation, efforts, and data availability between countries, often limiting surveillance efficiency. Chronic wasting disease (CWD) is a contagious prion disease of cervids. The long incubation period and slow initial epidemic growth make it notoriously difficult to detect CWD in the early phase of an epidemic. The recent emergence of CWD in wild reindeer in Norway poses a threat to approximately 250,000 semi-domesticated reindeer in Norway and 250,000 in Sweden, including transboundary populations. Here, we provide a first analysis of surveillance data (2016–2022) from all reindeer districts in Norway and Sweden to determine the probability of freedom from CWD infection. During the six years, 6017 semi-domesticated reindeer were tested in Sweden and 51,974 in Norway. Most samples came from healthy slaughtered animals (low risk). Reindeer use large and remote areas and (high risk) samples from fallen stock and animals with clinical signs were difficult to obtain. A scenario tree model was run for seven different set of values for the input parameters (design prevalence within and between districts, probability of introduction, and relative risks) to determine the effect on surveillance sensitivity. At the national level, the mean probability of disease freedom was 59.0 % in Sweden and 87.0 % in Norway by 2021. The most marked effect on sensitivity was varying the design prevalence both within and between districts. Uncertainty about relative risk ratios affected sensitivity for Sweden more than for Norway, due to the higher proportion of animals in the high-risk group in the former (13.8 % vs. 2.1 %, respectively). A probability of disease freedom of 90 % or higher was reached in 8.2 % of the 49 districts in Sweden and 43.5 % of the 46 districts in Norway for a design prevalence of 0.5 %. The probability of freedom remained below 60 % in 29 districts (59.2 %) in Sweden and 10 districts (21.7 %) in Norway. At the national level, only Norway had a sufficiently large number of samples to reach a probability of more than 95 % of disease freedom within a period of 10 years. Our cross-border assessment forms an important knowledge base for designing future surveillance efforts depending on the spatial pattern of prevalence of CWD and risk of spread.

Inter- and intra-species conversion efficacies of Norwegian prion isolates estimated by serial protein misfolding cyclic amplification

Prion diseases, including chronic wasting disease (CWD) in cervids, are fatal neurodegenerative disorders caused by the misfolding of cellular prion proteins. CWD is known to spread among captive and free-ranging deer in North America. In 2016, an outbreak of contagious CWD was detected among wild reindeer in Norway, marking the first occurrence of the disease in Europe. Additionally, new sporadic forms of CWD have been discovered in red deer in Norway and moose in Fennoscandia. We used serial protein misfolding cyclic amplification to study the ability of Norwegian prion isolates from reindeer, red deer, and moose (two isolates), as well as experimental classical scrapie from sheep, to convert a panel of 16 brain homogenates (substrates) from six different species with various prion protein genotypes. The reindeer CWD isolate successfully converted substrates from all species except goats. The red deer isolate failed to convert sheep and goat substrates but exhibited amplification in all cervid substrates. The two moose isolates demonstrated lower conversion efficacies. The wild type isolate propagated in all moose substrates and in the wild type red deer substrate, while the other isolate only converted two of the moose substrates. The experimental classical scrapie isolate was successfully propagated in substrates from all species tested. Thus, reindeer CWD and classical sheep scrapie isolates were similarly propagated in substrates from different species, suggesting the potential for spillover of these contagious diseases. Furthermore, the roe deer substrate supported conversion of three isolates suggesting that this species may be vulnerable to prion disease.

No evidence of uptake or propagation of reindeer CWD prions in environmentally exposed sheep

BackgroundChronic wasting disease (CWD) is a prion disease of cervids first reported in North America in the 1960s. In Europe, CWD was first diagnosed in 2016 in a wild reindeer in Norway. Detection of two more cases in the same mountain area led to the complete culling of this partially confined reindeer population of about 2400 animals. A total of 19 CWD positive animals were identified. The affected area is extensively used for the grazing of sheep during summers. There are many mineral licks intended for sheep in the area, but these have also been used by reindeer. This overlap in area use raised concerns for cross-species prion transmission between reindeer and sheep. In this study, we have used global positioning system (GPS) data from sheep and reindeer, including tracking one of the CWD positive reindeer, to investigate spatial and time-relevant overlaps between these two species. Since prions can accumulate in lymphoid follicles following oral uptake, samples of gut-associated lymphoid tissue (GALT) from 425 lambs and 78 adult sheep, which had grazed in the region during the relevant timeframe, were analyzed for the presence of prions. The recto-anal mucosa associated lymphoid tissue (RAMALT) from all the animals were examined by histology, immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA), and the ileal Peyer's patch (IPP) from a subsample of 37 lambs were examined by histology and IHC, for the detection of prions.ResultsGPS data showed an overlap in area use between the infected reindeer herd and the sheep. In addition, the GPS positions of an infected reindeer and some of the sampled sheep showed temporospatial overlap. No prions were detected in the GALT of the investigated sheep even though the mean lymphoid follicle number in RAMALT and IPP samples were high.ConclusionThe absence of prions in the GALT of sheep that have shared pasture with CWD-infected reindeer, may suggest that transmission of this novel CWD strain to sheep does not easily occur under the conditions found in these mountains. We document that the lymphoid follicle rich RAMALT could be a useful tool to screen for prions in sheep.

Accelerating advances in landscape connectivity modelling with the ConScape library

AbstractIncreasingly precise spatial data (e.g. high‐resolution imagery from remote sensing) allow for improved representations of the landscape network for assessing the combined effects of habitat loss and connectivity declines on biodiversity. However, evaluating large landscape networks presents a major computational challenge both in terms of working memory and computation time. We present theConScape(i.e. “connected landscapes”) software library implemented in the high‐performance open‐source Julia language to compute metrics for connected habitat and movement flow on high‐resolution landscapes.The combination of Julia's ‘just‐in‐time’ compiler, efficient algorithms and ‘landmarks’ to reduce the computational load allowsConScapeto compute landscape ecological metrics—originally developed in metapopulation ecology (such as ‘metapopulation capacity’ and ‘probability of connectivity’)—for large landscapes. An additional major innovation inConScapeis the adoption of the randomized shortest paths framework to represent connectivity along the continuum from optimal to random movements, instead of only those extremes.We demonstrateConScape's potential for using large datasets in sustainable land planning by modelling landscape connectivity based on remote‐sensing data paired with GPS tracking of wild reindeer in Norway. To guide users, we discuss other applications, and provide a series of worked examples to showcase allConScape's functionalities in Supplementary Material.Built by a team of ecologists, network scientists and software developers,ConScapeis able to efficiently compute landscape metrics for high‐resolution landscape representations to leverage the availability of large data for sustainable land use and biodiversity conservation. As a Julia implementation,ConScapecombines computational efficiency with a transparent code base, which facilitates continued innovation through contributions from the rapidly growing community of landscape and connectivity modellers using Julia.

Chronic Wasting Disease (CWD) in Sami Reindeer Herding: The Socio-Political Dimension of an Epizootic in an Indigenous Context.

Simple SummaryChronic wasting disease (CWD), the most transmissible of the prion diseases, was detected in 2016 in Norway in a wild reindeer. This is the first case in Europe, an unexpected one. This paper focuses on the issues that the arrival of CWD raises in Northern Europe, especially regarding the Indigenous Sami reindeer husbandry in Sweden. The study offers a diagnosis of the situation regarding the management of the disease and its risks. We present the importance of the involvement of the Sami people in the surveillance program in order to understand better the diseases and the reindeer populations, movement, and behavior. However, the implementation of new European health standards in the Sami reindeer herding could have tremendous consequences on the evolution of this ancestral activity and the relationship between herders and reindeer.Chronic wasting disease (CWD) is the most transmissible of the prion diseases. In 2016, an unexpected case was found in Norway, the first in Europe. Since then, there have been 32 confirmed cases in Norway, Sweden, and Finland. This paper aims to examine the situation from a social and political perspective: considering the management of CWD in the Swedish part of Sápmi—the Sami ancestral land; identifying the place of the Sami people in the risk management–because of the threats to Sami reindeer herding that CWD presents; and understanding how the disease can modify the modalities of Indigenous reindeer husbandry, whether or not CWD is epizootic. Based on interviews with various stakeholders and by examining the social sciences literature, this paper shows that the health risk management is structured by a politico-scientific controversy about the recognition, or not, of atypical and classical CWD. The Sami herders are currently cooperating with the state authorities in the surveillance program to sample their herds. This involvement takes place in a situation where the balance of power between the Sami people and the state, or the European Union, is framed by its colonial context. This has consequences with respect to the definition of a common interest and to implementing sanitary measures. The particular features of reindeer herding are seen as a challenge to managing CWD risk, compared with European health standards. We argue that CWD will greatly modify the modalities of Indigenous reindeer herding, whether there are positive cases or not in the Sami reindeer. By implementing new health guidelines, the authorities will create a cascading effect in Sami land and its use. The CWD situation in Fennoscandia is full of uncertainty but may cause a major shift in the organization and the governance of Sápmi. In September 2020, the identification of a new CWD case in a wild reindeer in Norway started a new episode in the disease management in Fennoscandia. Our paper raises various questions linked to understanding this new step in this crisis which is not only epidemiological, but also socio-cultural and political.

Assessing the Significance of Model Selection in Ecology

Model Selection is a key part of many ecological studies, with Akaike’s Information Criterion (AIC) being by far the most commonly used technique for this purpose. Typically, a number of candidate models are defined a priori and ranked according to their expected out-of-sample performance. Model selection, however, only assesses the relative performance of the models and, as pointed out in a recent paper, a large proportion of ecology papers that use model selection do not assess the absolute fit of the ‘best’ model. In this paper, it is argued that assessing the absolute fit of the ‘best’ model alone does not go far enough. This is because a model that appears to perform well under model selection is also likely to appear to perform well under measures of absolute fit, even when there is no predictive value. A model selection permutation test is proposed that assesses the probability that the model selection statistic of the ‘best’ model could have occurred by chance alone, whilst taking account of dependencies between the models. It is argued that this test should always be performed as a part of formal model selection. The test is demonstrated on two real population modelling examples of ibex in northern Italy and wild reindeer in Norway.

Novel Type of Chronic Wasting Disease Detected in Moose (Alces alces), Norway

Chronic wasting disease (CWD) persists in cervid populations of North America and in 2016 was detected for the first time in Europe in a wild reindeer in Norway. We report the detection of CWD in 3 moose (Alces alces) in Norway, identified through a large scale surveillance program. The cases occurred in 13–14-year-old female moose, and we detected an abnormal form of prion protein (PrPSc) in the brain but not in lymphoid tissues. Immunohistochemistry revealed that the moose shared the same neuropathologic phenotype, characterized by mostly intraneuronal deposition of PrPSc. This pattern differed from that observed in reindeer and has not been previously reported in CWD-infected cervids. Moreover, Western blot revealed a PrPSc type distinguishable from previous CWD cases and from known ruminant prion diseases in Europe, with the possible exception of sheep CH1641. These findings suggest that these cases in moose represent a novel type of CWD.

A reindeer cull to prevent chronic wasting disease in Europe.

The emergence of chronic wasting disease among wild reindeer in Norway triggered the decision to eradicate an entire population of more than 2,000 animals. The cull, now complete, was a tremendously difficult process both politically and practically.

High prevalence of prion protein genotype associated with resistance to chronic wasting disease in one Alberta woodland caribou population

ABSTRACTChronic wasting disease (CWD) is a prion disease found in deer, elk and moose in North America and since recently, wild reindeer in Norway. Caribou are at-risk to encounter CWD in areas such as Alberta, Canada, where the disease spreads toward caribou habitats. CWD susceptibility is modulated by species-specific polymorphisms in the prion protein gene (Prnp). We sequenced Prnp of woodland caribou from 9 Albertan populations. In one population (Chinchaga) a significantly higher frequency of the 138N allele linked to reduced CWD susceptibility was observed. These data are relevant for developing CWD management strategies including conservation of threatened caribou populations.

Public perceptions of planning objectives for regional level management of wild reindeer in Norway

We examined community perceptions of preferred objectives for wild reindeer management in Southern Norway as the former population-based model is being replaced with an area-based, multi-level regional management model spanning large mountain regions. Communally oriented objectives are favoured over economic benefits to landowners. Environmental attitudes discriminate on many of the issues and can be useful factors in sorting out levels of support for proposed management actions and compromises in land use decisions. The regional reindeer plans create a new political context for land use management across large mountain areas which will require better cooperation among municipalities.

Wild reindeer in Norway – population ecology, management and harvest

Wild reindeer in Norway – population ecology, management and harvest

Calving time and foetus growth among wild reindeer in Norway

Mean calving dates among 7 wild reindeer (Rangifer t. tarandus) herds in southern Norway varied between the 6th and the 27th of May. Ln transformed foetus weights relate linearly to ln age in days. Regression analyzes based upon 225 days pregnancy predicts birth wet weights between 4600 and 7500 g in the different areas and years. At 130 days, foetus weights varied between 547 and 746 g (mean=681, standard deviation s=63) in all areas and years, indicating that foetus growth up to this size is independent of mothers body weight or condition. During the remaining 95 days of pregnancy, very poor body condition, reflected in dressed weights, resulted in slower foetus growth and smaller regression estimated birth weights. The foetus weight variation recorded at similar dates within areas and sampling years indicates a dispersed breeding time mostly within two ovulations. A small sample of foetuses from pregnant yearlings and calves indicate that these cohorts conceive later than 2 yr + females. Assuming similar foetus growth pattern among all female age cohorts within areas, yearlings conceive around 1 week later and calves (in Ottadalen) more than 3 weeks later than 2 + yr olds.

Management of wild reindeer in Norway

Wild reindeer in Norway are found in 26 separate management areas. Predators are virtually absent from all areas and hunting is the most important factor determining population development through alterations of herd size and structure. Average population density (animals/km2) after hunt was 1.96 in Hardangervidda, 1.18 in North Rondane and between 0.78 and 0.87 in Rondane South, Snøhetta, North Ottadalen and Forelhogna. Body size and female pregnancy rates followed a reverse trend. Average net increase of the herds varied from 42.2±10.0% in Forelhogna to 18.8±8.0% in Rondane North. In areas with animals in prime physical condition a high versus a low average harvest rate of calves resulted in a similar number of animals harvested, but a lower total yield of meat and revenue from hunting licences. At a winter population density of 0.8 - 2.0 animals/km2 annual harvest (per km2) of wild reindeer amounts to 0.23 - 0.51 animals, 9 - 18 kg meat and 286 - 850 NKr from sale of hunting licences. There was a significant relationship between body size expressed as carcass weights or mandible length and harvest success.

An Energy Model for Adult Female Caribou of the Denali Herd, Alaska

Estimates of the energy costs of resting, activity, and productive processes from the literature were applied to caribou activity budgets and movements documented during 1978-80 to estimate seasonal and annual energy requirements of adult female caribou (Rangifer tarandus granti) in Denali National Park and Preserve. Energy requirements were 45% lower in winter than summer, primarily because of a 21% reduction in resting metabolic rate and benefits of fat catabolism in winter, and high summer costs of lactation, fat deposition, and activity. Estimated energy requirements totaled 38.2 MJ . day-' during the insect season, 36.7 during summer migration, 34.2 during fall migration, 31.9 during prerut and rut, 29.3 during calving and postcalving, 23.7 during early and late winter migrations, 21.6 during early winter, 20.9 during late winter, and 20.5 during midwinter. Annual energy requirements, including costs of pregnancy (368.6 MJ) and lactation (560.3), totaled 9,870 MJ, excluding costs of cratering through snow and apparently minor costs of physiological stress. Compared to studies of food energy requirements of penned caribou, the model gives accurate predictions of total metabolizable energy requirements when allowances are made for the relative inactivity of penned animals. Modeling the energy requirements of an ungulate population is a prerequisite to estimating nutritional carrying capacities (Moen 1973, Robbins 1973, Wallmo et al. 1977, Mautz 1978). Measurements of the energy requirements of Rangifer have received emphasis in several studies (Makarova and Segal 1958, Hammel et al. 1961, Segal 1962, McEwan 1970, Luick et al. 1974, Young and McEwan 1975, White and Yousef 1978), but these measurements have not previously been used to model seasonal energy requirements of a caribou/ reindeer (Rangifer tarandus) population. Author is game research biologist, Alaska Department of Fish and Game, 1300 College Road, Fairbanks, Alaska 99701. At the time of the research, author was graduate student, Alaska Cooperative Wildlife Research Unit, University of Alaska, Fairbanks. Financial and logistical support was provided by the U.S. National Park Service (contract CX-9000-7-E080). Manuscript accepted May 28, 1985. Thomson (1977) attempted to model the year-round energy expenditure of wild reindeer in Norway using estimates of energy expenditure from the literature. However, Thomson's applications of energy costs differed in several ways from those presented here, making comparisons difficult. The most significant deviations included Thomson's exclusion of estimates for the calorigenic effect of food and his extremely high estimate for the energy cost of trotting. Gaare et al. (1975) also estimated seasonal energy requirements of wild reindeer in Norway. However, their estimates are about 45% of those reported here. Since they did not present energy-cost estimates of the various activities, it is impossible to account for the difference. White et al. (1975) estimated the summer energy requirements for caribou activity as simply 2 X basal metabolic rate (BMR). However, they used a winter-BMR value, so their summer energy estimates are substantially lower than presented here. I studied the Denali (formerly McKinley) caribou herd in Denali National Park and Preserve, Alaska during 1978-80. A model of the nutritional ecology of the herd was developed to assess the energetic/ nutritional status of this extremely reduced population (Boertje 1981). This paper demonstrates the applicability of measurements of energy costs by modeling metabolizable energy requirements of adult female caribou in the Denali herd.

Reproduction in wild reindeer in Norway

Pregnancy status and dressed weights were obtained from female reindeer killed during autumn and winter in five areas in southern Norway. Body weight, mandible length, and lactation status were obtained from females killed during the hunting season in the same areas. Pregnancy rates (P) were predictable from the female dressed weight at rut (W), from the equation P = 1–e[−0.169(W–21)]. In areas where calves become pregnant, yearlings may have a lower pregnancy rate than expected from their weights.

Growth in Domestic and Wild Reindeer in Norway

Growth is compared between two wild reindeer ( vRangifer tarsndus ) populations and also be- tween these two populations and the now-dispersed Trio domestic herd from which the two aFild popula- tions were derived. The two wild populations are located in North Ottadalen a near-virgin area, and South Ottadalen an area that was partially heavily grazed. Both areas vere utilized by the Trio herd. Intensive herding of the Trio animals is deemed responsible for their 23 to 43 percent losver dressed weights when compared with the South Ottadalen herd. The longer diastema lengths of the North Otta- dalen population,, when compared with both the South Ottadalen and the Trio populations, reflect the dif- ference in range quality between the North and South Ottadalen areas. GROWTH IN DOMESTIC AND WILD REINDEER IN NORWAY EIGIL REIMERS, The Norwegian Stote Game Reseorch Institute, Vollebekk Abstract: Growth is compared between two wild reindeer ( vRangifer tarsndus ) populations and also be- tween these two populations and the now-dispersed Trio domestic herd from which the two aFild popula- tions were derived. The two wild populations are located in North Ottadalen a near-virgin area, and South Ottadalen an area that was partially heavily grazed. Both areas vere utilized by the Trio herd. Intensive herding of the Trio animals is deemed responsible for their 23 to 43 percent losver dressed weights when compared with the South Ottadalen herd. The longer diastema lengths of the North Otta- dalen population,, when compared with both the South Ottadalen and the Trio populations, reflect the dif-

Reaction of Reindeer to Obstructions and Disturbances

In Scandinavia, highways and railroads have not generally created obstructions to the movement of domesticated reindeer, although thousands of animals are killed each year in accidents. Some disruption in the movements of wild reindeer in Norway has been associated with the construction of a railroad and highway through an alpine plateau south of Trondheim. Hydroelectric projects have had the greatest detrimental effects on reindeer by flooding rangelands and obstructing migration routes. Special problems are created by the fluctuating water levels in reservoirs and rivers; efforts to mitigate the effects of these fluctuations have been only partially successful. Reindeer have strong traditions for migrating along specific routes, and realignment of these routes is extremely difficult. Conflicts of interest exist between reindeer herders and foresters. During their winter feeding, the deer damage young trees. The cutting of forests usually results in a deterioration of the area as a rangeland for reindeer. Herbicides used in forestry have been implicated in the death of some reindeer in Sweden, and research is now under way to determine the effects of herbicides on reindeer. The increased use of fences in reindeer husbandry in Scandinavia has emphasized the fact that reindeer behavior and characteristics of the terrain must be considered if fences are to be successful in directing or controlling the movements of reindeer. Herders now use snowmobiles instead of reindeer for transportation and herding, but the machines disturb the reindeer and must be used with discretion. Recent evidence indicates that large amounts of industrial waste in the atmosphere are carried from the British Isles and central Europe to Scandinavia, where they fall out in rain and snow. This has raised concern about the influence of the wastes on lichens, the main winter food supply of reindeer. Studies are now under way in Finland, Sweden, and Norway, through the International Biological Program, to determine the growth rates of the several lichen species that are important to reindeer.