Climate warming impacts tuttuk (caribou) forage availability in Tongait (Torngat) Mountains, Labrador

Tuttuk (caribou ( Rangifer tarandus)) populations are in decline across Canada, making them a major conservation concern for Inuit of Nunatsiavut (Northern Labrador) and Nunavik (Northern Quebec). This study investigates changes to caribou forage over 14 years at two tundra sites in northern Nunatsiavut, Labrador. We ask: (1) How much of the total vegetation is suitable caribou forage and how has this changed with time and experimental warming; and (2) which forage species are most affected by recent climate change? At control and warming plots, we identified selected, edible, and avoided caribou forage based on published literature, and modeled observed changes in forage availability. We found that the relative frequency of selected winter forage was lower than summer forage at both sites. Caribou appear to be more forage limited in the winter than summer, and birch ( Betula spp.), and ericaceous shrub species ( Vaccinium spp.), increased over time. Our research provides valuable insight into recent changes in caribou forage availability and develops a novel methodology that can be applied across other caribou ranges. This knowledge will inform conservation and management measures by helping identify possible forage limitations and can contribute to recovery targets across Nunatsiavut and ultimately the social-ecological resilience of northern communities.