Supervised by:

Dominique Berteaux (Regular member)

Research project description

Movement ecology of a mammal herbivore in the Arctic polar desert

IntroductionThe Arctic polar desert is an extreme environment, characterized by very low temperatures and primary productivity. In such poor and variable environments, animal migration is a common behavioral adaptation, especially in birds. However, this phenomenon is rather rare in terrestrial mammals. The Arctic hare, one of the few resident mammals of the Arctic, has many adaptations allowing it to persist in this environment. In 2019, a fall mass movement was described in this species on Ellesmere Island. This seems to indicate that the hare's movements play an important role in its ability to persist in this environment. In the current context of climatic and anthropogenic disturbances affecting the Arctic, understanding the role of movement in the survival strategies of species undergoing these radical changes is of particular importance.ObjectivesThe overall goal of my PhD is to understand how mammalian herbivores use movement to persist in the most hostile environments on Earth. I will use the Arctic hare as a study model to understand the movement strategies allowing herbivores to survive in the Canadian polar desert. I will adopt a 3-step approach, according to the main phases of the annual life cycle of the species: summer reproduction, fall and spring migrations, and winter residence. Thus, my specific objectives are the following: 1) To understand the strategies of space use during the polar summer, a period of reproduction and abundance of resources. 2) To identify individual and environmental factors explaining migratory routes. 3) To describe the spatial use of individuals during the polar winter, when environmental conditions pose the greatest challenge to survival.Study sitesI will study the Arctic hare population that breeds around Canadian Forces Station Alert, northeast of Ellesmere Island, Nunavut. The ecosystem and climate are typical of the polar desert, with a very short summer period without frost and very little precipitation. The region around the station is rugged and hilly, with numerous plateaus surrounded by ravines and canyons. In winter, the movements of hares allow them to disperse across northeast Ellesmere Island (Nunavut), to Lake Hazen, in the middle of Quttinirpaaq National Park of Canada. The region surrounding Lake Hazen is a thermal oasis and is distinguished from the rest of the island by a less rugged terrain, a greater supply of water flowing from the glaciers and a milder and damper climate, all of which allowing a richer vegetation.Material and methodsDuring the field season, I will analyze the movements, activity and behaviors of individuals over the summer, taking into account individual and environmental characteristics. At the beginning of the season, I will equip individuals with collars equipped with GPS and accelerometers to record data several times per hour during the summer. At the end of the summer, I will equip other individuals with collars equipped with GPS and accelerometers capable of transmitting hourly data by satellite. I will complete my dataset with environmental information acquired by remote sensing (elevation, slope, snow on the ground, annual primary production). Collars placed in late summer will also provide data during winter. I will analyze the degree of activity and the movements of individuals with regard to individual and environmental characteristics.Expected resultsMy project will advance innovative goals according to recent literature, by combining an almost unknown study system with state-of-the-art methodological approaches. My PhD will thus shed light on both the ecology of migration in terrestrial mammals and the functioning of vertebrate communities in the High Arctic. The arctic hare's extreme living environment and unique characteristics make it a particularly interesting model for studying mammalian adaptations to harsh environmental conditions.