Des Ursulines Building
300 Allée des Ursulines
In the arctic tundra, predation is an important top-down force that has direct and indirect impacts on the animal community. For example, direct impacts are known to control lemming cyclic fluctuations in the Arctic. Predators also have indirect impacts by forcing avoidance behavior of the potential prey. These potential prey may preferably use habitats where predator abundance is low. At the local scale, the impact of predation on the animal communities depends on the movement and the habitat selection pattern of those predators. This suggest a link between predator spatial distribution and local arctic biodiversity patterns. However, knowledge on fine scale spatial distribution of predators is scarce, especially for a common arctic predator, the arctic fox (Vulpes lagopus).
Therefore, the aim of my project is to explain movement and habitat selection of arctic foxes inside their territories, using a hierarchical approach. More precisely, I will 1) map at fine scale arctic fox habitats, 2) assess territory habitat selection and 3) assess step decisions at the step scale.
The tundra of Bylot island (73°N, 79°W, NU) is an oasis of productivity and biodiversity in the Canadian High Arctic. Considering this richness and the presence of shared predators to many prey species, the site offers great opportunities to study the relations between predation and local scale biodiversity patterns.
I will use 4-minute interval GPS locations of 8 arctic foxes to define which habitat variables affect the spatial distribution of individuals within their territory. Many variables known to impact arctic fox decisions will be tested (e.g. prey availability, habitat complexity, territoriality). The first step of the hierarchical approach is a resource selection function (RSF). Using a sub-sample of the dataset, this analysis will define habitat selection patterns at the territory scale (8-10km2). The second step is an analysis of step-selection function (SSF). By comparing variables of used steps to those of available steps (4 minutes), this analysis includes movement mechanisms as a complementary process to explain fine scale habitat selection.
A better understanding of the arctic fox spatial distribution at the local scale is necessary to define the role of predation on the local distribution of arctic species. Considering the high diversity of birds nesting in the Arctic, this knowledge is valuable at the circumpolar scale.