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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Zhodnocení krmných dávek pro kopytníky v průběhu roku

Čepelka, Ladislav January 2010 (has links)
No description available.
2

Variation in the blood chemical constituents of reindeer:significance of season, nutrition and other extrinsic and intrinsic factors

Säkkinen, H. (Hannele) 09 August 2005 (has links)
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.
3

Möjligheten att återintroducera skogsvildrenen till Sverige : Återintroduktionens påverkan i området mellan Mora, Leksand och Vansbro / The possibility of reintroducing wild forest reindeer in Sweden : Reintroductions impact in the geographical area between Mora, Leksand and Vansbro

Persson, Linn January 2016 (has links)
The purpose of this study was to investigate if Sweden should reintroduce wild forest reindeer (Rangifer tarandus fennicus Lönn) to the Swedish fauna and what conditions there were for a reintroduction to Vildmarksriket between Mora, Leksand and Vansbro. The purpose was also to investigate the impact of the reintroducement of the stakeholders in the area, such as forest owners, farmers, authorities, organizations and local residents. The methods used were a quantitative attitude survey which consisted of questionnaires and qualitative interviews. The interviews were strategically selected and semi-structured. The conclusion of this study was that stakeholders in the area Vildmarksriket have different opinions about the wild forest reindeer. The issue that concern stakeholders the most and that can create anxiety and conflict in Vildmarksriket is whether the wolves and the bears will be affected by wild forest reindeer and how forestry can be affected. Generally there is a positive attitude towards wild forest reindeer, but there is also a strong uncertainty. Wild forest reindeer can affect species and ecosystems in the region, but the effect seems to be small regardless of whether they are negative or positive. Vildmarksriket still has the potential to be a suitable area for wild forest reindeer to be reintroduced. According to the legislation that exists today, Sweden has no direct juridical obligation to reintroduce wild forest reindeer.
4

Optimal foraging in an Arctic herbivore : How does the foraging behaviour of Svalbard reindeer (Rangifer tarandus platyrhynchus) respond to seasonal changes from summer through autumn of the Arctic tundra?

Djurberg, Emma Limosa January 2023 (has links)
Foraging decisions of large herbivores can be affected by many factors and have great effect on both above- and below-ground ecosystems. Here, I determine to which degree temporal (seasonality), or spatial (habitat) factors influence the foraging behaviour of Svalbard reindeer (Rangifer tarandus platyrhynchus) and asses if small-scale foraging behaviour correlates with an animals’ patch residence time. I analysed behavioural observations on 15 Svalbard reindeer between summer and autumn 2022, recording both behaviour and habitat use. Using mixed-effects multinomial logistic regression, the interaction between seasonal change from summer to autumn and habitat best explained the variation in Svalbard reindeer foraging behaviour. The foraging behaviour “standing-grazing” was found to have the highest observed amount in all habitat types and increased over the growing season. Contrastingly, the foraging behaviour of “walking-grazing” had its highest abundance in the beginning of the study period, and then decreased over the course of the season for all analysed habitats. In addition, “walking-grazing” was found to be significantly correlated with patch residency time and decreased the longer an individual stayed in a patch. With presumable high plant quality early in the season, my results imply how Svalbard reindeer are greatly stationary foragers, but prioritizing to become relatively mobile when it is beneficial. Thus, highlighting how Svalbard reindeer respond dynamically to shifts in foraging conditions. These findings provide knowledge about what factors may impact the foraging behaviours of Arctic herbivores and helps contribute to a broader understanding of how changes in foraging behaviours may alter arctic ecosystems.
5

Les paysages culturels de l’élevage de rennes en Scandinavie face au changement global : une approche multi-scalaire (Laponie suédoise, Sud norvégien) / Cultural landscapes of the Scandinavian reindeer herding facing the global change : a multi-scalar approach (Swedish Lappland, southern Norway)

Courault, Romain 05 December 2018 (has links)
Les régions subarctiques font face aux effets interconnectés et pluri-scalaires du changement global (amplification des extrêmes bioclimatiques et intensification dans l’utilisation des sols). Le renne, Rangifer tarandus est un grand herbivore qui migre annuellement sur de grands espaces pour ses besoins biologiques. L’ongulé cristallise de nombreux enjeux paysagers pour les pastoralismes saamis. Plusieurs populations de rennes seront étudiées dans un suivi multi-scalaire. Nous évaluons les effets directs du changement global (fragmentation paysagère et changements climatiques) sur les paysages culturels de Scandinavie en lien avec la démographie des rennes. Par la suite, la descente en échelle géographique nous permet de caractériser via satellite et relevés floristiques les effets du changement global sur les paysages végétaux de la communauté montagnarde d’éleveurs Gabna, dans le nord de la Suède. Nous étudions ensuite les comportements migratoires des rennes sauvages norvégiens, pour appréhender les liens entre variabilité bioclimatique et écologie spatiale de l’herbivore. Les résultats principaux rejoignent ceux de la littérature scientifique, appliqués aux espaces étudiés : régionalement, changement des climats et pertes significatives en pâturages ; localement, boréalisation et embroussaillement des paysages migratoires. Les liens forts entre une partie des effets cumulés du changement global et la biogéographie scandinave de Rangifer tarandus sont ainsi discutés. L’approche paysagère dans les problématiques environnementales complexes (revendication territoriale) a révélé l’importance de l’éthique dans le dialogue science/minorités. / Les régions subarctiques font face aux effets interconnectés et pluri-scalaires du changement global (amplification des extrêmes bioclimatiques et intensification dans l’utilisation des sols). Le renne, Rangifer tarandus est un grand herbivore qui migre annuellement sur de grands espaces pour ses besoins biologiques. L’ongulé cristallise de nombreux enjeux paysagers pour les pastoralismes saamis. Plusieurs populations de rennes seront étudiées dans un suivi multi-scalaire. Nous évaluons les effets directs du changement global (fragmentation paysagère et changements climatiques) sur les paysages culturels de Scandinavie en lien avec la démographie des rennes. Par la suite, la descente en échelle géographique nous permet de caractériser via satellite et relevés floristiques les effets du changement global sur les paysages végétaux de la communauté montagnarde d’éleveurs Gabna, dans le nord de la Suède. Nous étudions ensuite les comportements migratoires des rennes sauvages norvégiens, pour appréhender les liens entre variabilité bioclimatique et écologie spatiale de l’herbivore. Les résultats principaux rejoignent ceux de la littérature scientifique, appliqués aux espaces étudiés : régionalement, changement des climats et pertes significatives en pâturages ; localement, boréalisation et embroussaillement des paysages migratoires. Les liens forts entre une partie des effets cumulés du changement global et la biogéographie scandinave de Rangifer tarandus sont ainsi discutés. L’approche paysagère dans les problématiques environnementales complexes (revendication territoriale) a révélé l’importance de l’éthique dans le dialogue science/minorités.
6

Long-term Habitat Trends in Barren-ground Caribou

White, Lori 28 January 2013 (has links)
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.
7

Motorized backcountry recreation and stress response in Mountain Caribou (Rangifer tarandus caribou)

Freeman, Nicola L. 11 1900 (has links)
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.
8

Use of fecal DNA to estimate population demographics of the Boreal and Southern Mountain ecotypes of woodland caribou

Hettinga, Peter N. 09 September 2010 (has links)
This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.
9

Long-term Habitat Trends in Barren-ground Caribou

White, Lori 28 January 2013 (has links)
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.
10

Use of fecal DNA to estimate population demographics of the Boreal and Southern Mountain ecotypes of woodland caribou

Hettinga, Peter N. 09 September 2010 (has links)
This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.

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