Review of the ecology of Canadian reindeer (Rangifer tarandus) populations

Abstract : ln the current climatic and environmental circumstances, caribou and reindeer (Rangifer tarandus) herds living across the circumpolar range are rapidly declining, as well as their habitats are constantly facing the double threat of global warming and anthropogenic landscape disturbance, leading to a persistent degradation of the fragile ecosystems of the Arctic.

Rangifer populations exhibit a great variation in ecology, genetics, behavior, and morphology, resulting in a wide geographical distribution across the northern regions of America, Europe and Asia. Therefore  the classification below the species level can be challenging.  The particular environment in which these large herbivores currently live could once be found in today's temperate latitudes of middle Europe.  The remains  found on a great number of archaeological sites prove that Rangifer once covered the European landscape and meant a great deal to the economic system of hunter-gatherers societies during Paleolithic  times. Understanding the ecological  versatility of this species today could possibly lead to try and evaluate  if the variability  of their ecological niches were formerly higher than what can be inferred from current ecosystems [1].

Here, we present a selection of articles aiming to clarify the ecological range of this species, to contribute to a better understanding of their biological and behavioral characteristics.

Even just by focusing on North American populations, one can realize the great diversity that this species presents. lndeed, here there are known to be four main extant subspecies [2] and each of these populations occupies a unique ecozone, where they're subject to highly variable limiting factors, such as climatic conditions and their influence on food availability, predation pressure,  pathogens,  or several factors combined [3]. Although these factors are partially responsible for the fluctuation of a population's size, which naturally varies over periodic cycles of several years [4], it is important to note that for the last two decades, with the constant development of industrial activities, most of the North American caribou populations have synchronously waned and are now recognized as endangered [5].

ln this context, focusing on the study of one particular Rangifer population such as the Qamanirjuaq's herd can provide an ideal example of how the limiting factors can affect the niches of this species even on a subpopulation living over a more restricted area [6]. Eventually, the establishment of an ecological balance sheet of modern North American Rangifer can help us acquire fundamental knowledge about their capacity to face either natural and anthropogenic constraints.