Lac Guillaume-Delisle is in the Hudson Bay region of Québec, near the community of Umiujaq. This site extends from the coast of Hudson Bay, inland to the west side of Lac Eau Claire, and mainly covers the rivers of this region. Lac Eau Claire is not part of this site. Lac Guillaume-Delisle is located in a low-lying area, and as a result, many rivers flow into the lake, which in turn flow into Hudson Bay via the Goulet channel.
Habitats here are subarctic, and consist of a patchwork of coniferous forests and open tundra, which forms an irregular transition from continuous boreal forest to arctic tundra.
A large part of the Hudson Bay region of Québec was surveyed for Harlequin Ducks during the 1992 breeding season. This survey detected 415 individuals, of which 27%, or 114 were in the Lac Guillaume-Delisle basin. This is 8 or 9% of the eastern Harlequin Duck population. In 1991, there were a minimum of 6 pairs and 1 non-mated adult, whereas in 1992, the 114 birds were divided into 86 mated and 28 non-mated adults.
At least seven Golden Eagle pairs nest on the site, and a nesting pair of Peregrine Falcons was reported on one of the islands in Lac Guillaume-Delisle.
BirdLife International (2020) Important Bird Areas factsheet: Rivers of the Lac Guillaume-Delisle Basin. Downloaded from http://www.birdlife.org on 27/10/2020.