Historical Changes and Current Distribution of Caribou, Rangifer tarandus , in Quebec

2003 
We examined published historical information, reports on aerial surveys conducted since 1953, and harvest data collected since 1971 to describe changes in the distribution and abundance of Caribou ( Rangifer tarandus ) in Quebec. The southern limit of the Caribou distribution diminished considerably in the late 19th century, and the decline in numbers probably continued until the 1960s and 1970s east of the 62nd meridian. South of the 49th parallel, only four small populations still persist. Despite the fact that all Caribou of the province were assigned to the same sub-species ( R. t. caribou ), three ecotypes with specific habitats and behaviour are found. The Barren-Ground ecotype, the only migratory form, is found north of the 52nd parallel. This ecotype currently occupies ≈ 255 000 km 2 in fall and winter, mainly in the ecological subzones of the forest tundra and the taiga. The Barren-Ground Caribou was characterized by a very low abundance from the end of the 19th century until the mid-1950s, but increased markedly thereafter reaching over a million individuals at the beginning of the 1990s. Populations of the Mountain ecotype have been identified in the southeastern and, possibly, in the northeastern parts of the province. The latter Mountain population is virtually unknown. The southeastern population is sedentary and uses mainly the boreal forest. This population has decreased over the last century and currently numbers only ≈ 140 individuals. Finally, the Forest-Dwelling ecotype is found discontinuously, mainly between the 49th and 55th parallels. Its current distribution covers ≈ 235 000 km 2 , mainly east of the 72nd meridian. This sedentary ecotype is found almost exclusively in the boreal forest, principally in areas with long forest fire cycles. Its abundance has also decreased over the years. Large Forest-Dwelling populations still persisted during the 1950s and 1960s, but they apparently disappeared. The current abundance is not known precisely, but based on density estimates and considering the current distribution, it probably does not exceed 3000 individuals. Current data are insufficient to identify precisely the causes of the population decline, although hunting seems to be an important proximal cause. Nous avons utilise les donnees historiques publiees, les rapports d’inventaires aeriens realises depuis 1953 et les statistiques de recolte sportive colligees depuis 1971 pour decrire les changements dans la repartition et l’abondance du Caribou ( Rangifer tarandus ) au Quebec. La limite meridionale de l’aire de repartition a beaucoup diminue a la fin du 19e siecle et la regression s’est probablement poursuivie durant les annees 1960 et 1970 a l’est du 62e meridien. Au sud du 49e parallele, on ne retrouve plus que quatre petites populations. Bien que tous les caribous du Quebec soient consideres appartenir a la meme sous-espece ( R. t. caribou ), on distingue trois ecotypes frequentant des milieux differents et arborant des comportements specifiques. Au nord du 52e parallele, on retrouve l’ecotype Toundrique, lequel est migrateur. Ces Caribous se repartissent sur ≈ 255 000 km 2 durant l’automne et l’hiver, principalement dans les sous-zones ecologiques de la toundra forestiere et de la taiga. Cet ecotype etait peu abondant entre la fin du 19e siecle et le milieu des annees 1950, mais il s’est accru considerablement pour atteindre plus d’un million d’individus au debut des annees 1990. Une population de l’ecotype Montagnard est presente au sud-est de la province et une autre existe possiblement au nord-est. Cette derniere n’est pas bien connue. Celle du sud-est utilise principalement la foret boreale. Cette population sedentaire a diminue considerablement depuis une centaine d’annees et elle ne compte plus qu’environ 140 individus. Finalement, l’ecotype Forestier est present de facon discontinue, principalement entre les 49e et 55e paralleles. Ces Caribous sont egalement sedentaires. On les retrouve presque exclusivement en foret boreale, principalement la ou le cycle des feux de foret est long. Leur repartition actuelle couvre ≈ 234 000 km 2 , principalement a l’est du 72e meridien. D’importantes populations forestieres existaient encore durant les annees 1950 et 1960, mais elles semblent avoir disparu. L’abondance actuelle n’est pas connue mais elle pourrait difficilement depasser 3000 individus si l’on se base sur les estimations de la densite et de l’aire de repartition. Les donnees disponibles sont insuffisantes pour identifier les causes exactes des diminutions d’effectifs bien que la chasse semble une cause proximale importante.
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