De nombreuses populations migratrices sont actuellement en déclin. Les changements climatiques entrainent des modifications dans les habitats des espèces migratrices et la phénologie des processus naturels, lesquels se répercutent sur la migration, une période critique pour ces espèces. Comprendre comment les variables environnementales et climatiques affectent la phénologie et les patrons de migration est donc crucial. Ma thèse s'intéresse à l'impact du climat, des ressources alimentaires et de la compétition sur les migrations printanières et automnales des caribous migrateurs, Rangifer tarandus, des troupeaux Rivière-George (TRG) et Rivière-aux-Feuilles (TRF) du Nord-du-Québec et du Labrador. Le premier volet de ma thèse propose une approche objective, basée sur la détection des changements dans la structure des déplacements saisonniers, pour identifier les dates de départ et arrivée en migration. Validée à l'aide de trajets simulés, elle a été appliquée aux migrations printanières et automnales de femelles caribous. Le second volet porte sur l'impact des conditions environnementales sur la phénologie des migrations de printemps et d'automne. Il montre que la phénologie de la migration est principalement affectée par les conditions climatiques rencontrées lors de la migration, les conditions d'enneigement affectant notamment les coûts des déplacements. Au printemps, les caribous subissent des conditions défavorables lorsque la fonte des neiges est précoce. À l'automne, ils semblent ajuster leurs déplacements et migrent plus vite quand la neige débute tôt pour limiter les coûts de déplacement dans une neige profonde. Le troisième volet porte sur les patrons de migration à l'automne et montre que ceux-ci sont affectés essentiellement par une compétition intra- et inter-troupeaux pour les aires d'hivernages. Les caribous du TRG répondent à une augmentation de la compétition sur les aires les plus proches de l'aire de mise bas, liée à une taille de population élevée, en migrant préférentiellement vers les aires les plus éloignées. L'utilisation des aires hivernales par les caribous du TRF est, quant à elle, contrainte par la présence et l’abondance du TRG, cette contrainte diminuant à mesure que le TRG décline et abandonne les migrations vers les aires d'hivernages communes aux deux troupeaux. Cette thèse améliore notre compréhension de l'influence des facteurs environnementaux sur la phénologie et les patrons de migration du caribou migrateur. Ces connaissances sont très utiles pour comprendre l'impact des changements climatiques et établir les plans de conservation pour les espèces migratrices. / Several populations of migratory species are actually declining. Climate changes affect the habitat of migratory species and the phenology of natural processes, and impact the migration, a critical period for migratory species. Thus, it is crucial to understand how environmental and climatic variables affect the timing and the patterns of migration. This thesis assesses the impact of climate, food resources and competition on the spring and fall migrations of migratory caribou, Rangifer tarandus, from the Rivière-George (RGH) and Rivière-aux-Feuilles (RFH) herds, in Northern Québec and Labrador. The first part of my thesis presents an objective approach, based on the detection of changes in the structure of seasonal movements, to assess the departure and the arrival dates of the migrations. The approach was validated on simulated paths, and was then applied on the spring and fall migrations of female caribou. The second part focuses on the impact of environmental conditions on the phenology of the spring and fall migrations. It revealed that migration is mainly affected by the climatic conditions encountered during migration, snow conditions partly determining the cost of movements. In the spring, caribou suffer from adverse conditions when the snowmelt is early. In the fall, caribou adjust their movements and migrate faster when snowfall occurs early to limit the cost of moving through deep snow. The third part of my thesis focuses on fall migration patterns and revealed that migration patterns are mainly affected by intra- and inter-herds competition for the winter ranges. Caribou from RGH migrate preferentially toward the furthest winter ranges in response to increased competition, linked with a high population size, limiting the competition on the closest winter ranges. The use of the winter ranges by caribou from RFH is constrained by the abundance of RGH. This constraint decreased as RGH declined and abandoned the migrations toward the winter ranges commonly used by both herds. My thesis increases our knowledge of the environmental factors that affect the phenology and patterns of caribou migrations. This knowledge is useful to understand the impact of climate changes and establish conservation plans for migratory species.

Orientadora: Profa. Dra. Marilda Aparecida de Menezes / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciências Humanas e Sociais, 2017. / O requerimento da experiência canadense é uma barreira que dificulta o acesso do imigrante qualificado a empregos com nível de qualificação equivalente. Inicialmente tomada como uma experiência de trabalho no Canadá ela demonstra ser um termo polissêmico diante dos diversos âmbitos em que se insere. Tomamos como objetivo desta pesquisa compreender de que forma a experiência canadense influencia na inserção dos imigrantes qualificados brasileiros no Canadá. Estabelecemos como objetivos específicos: contextualizar o campo em que se dá a experiência canadense; investigar o que é a experiência canadense para os imigrantes qualificados brasileiros no Canadá; e compreender a dinâmica em que o fenômeno da experiência canadense ocorre. A metodologia desta pesquisa se concentrou na pesquisa bibliográfica e na pesquisa de campo, sendo esta constituída da aplicação de questionário e entrevistas. Para a análise de dados dos resultados do questionário utilizamos estatística descritiva simples e para as entrevistas fizemos uso da grounded theory. Partimos da hipótese que a experiência canadense mobiliza primordialmente o capital cultural do imigrante qualificado brasileiro no Canadá. Para elucidar o problema de pesquisa utilizamos os conceitos de capital, habitus e campo de Bourdieu. Como resultados obtivemos que a experiência canadense atua como um processo de desvalorização e diferenciação dos imigrantes em diversos parâmetros, de maneira implícita e sutil. Caracterizando-a como o requerimento de um capital cultural que acaba por impor seu próprio tempo, não respeitando assim o processo de aquisição individual e gerando um habitus. Desta forma a experiência canadense acaba ferindo a proposta de multiculturalismo e integração canadense construída pelo país, apresentando um campo que vai além do mercado de trabalho no Canadá. / The Canadian experience requirement is a barrier that hinders skilled immigrants access to comparable qualifying jobs. Initially taken as a work experience in Canada, it proves to be a polysemyc term in front of the various values in which it is inserted. Based on that, this research aims to understand how the Canadian experience influences the insertion of qualified Brazilian immigrants in Canada. We set specific objectives: contextualize the field in which the Canadian experience takes place; investigate what is the Canadian experience for qualified Brazilian immigrants; and understand the dynamics in which this phenomenon occurs. The methodology used in this research was bibliography and field research, which consists of applying a questionnaire on the internet and interviews. To analyze the data gathered through the questionnaires we used simple descriptive statistics and to analyze the interviews we used grounded theory. The main hypothesis is that Canadian experience main function is to primarily mobilize the cultural capital of qualified Brazilian immigrants. To elucidate the research problem, it is used Pierre Bourdieu's concepts of capital, habitus and field. As a result, we concluded that Canadian experience acts as a process of devaluation and differentiation of immigrants in several parameters, implicitly and subtly. It is characterized as a requirement of a cultural capital that imposes its time and does not respect the process of individual acquisition, generating a habitus. We have found that the Canadian experience hurts the multiculturalism and integration proposal built by Canada, presenting a field that goes beyond the Canadian labor market.