Diet flexibility of wolves and black bears in the range of migratory caribou.

This article focuses on the dietary flexibility of wolves (Canis lupus) and black bears (Ursus americanus) in northern Québec and Labrador, Canada, within the ranges of two migratory caribou (Rangifer tarandus) herds: the high-abundance Rivière-aux-Feuilles herd (RFH) and the low-abundance Rivière-George herd (RGH). Using morphological, molecular, and stable isotope analyses, the study found that wolves in northern Québec primarily prey on caribou year-round, while those in northern Labrador exhibit more seasonal and varied diets including moose and fish, reflecting differences in caribou availability. Black bears showed seasonal and regional dietary variation, with caribou serving as a significant source of animal protein especially in northern Québec and during spring when calves are vulnerable. The findings highlight the adaptability of these predators’ diets in response to prey abundance and distribution, providing insights relevant to understanding predator-prey dynamics and informing conservation strategies for declining caribou populations in northern ecosystems.