In Hemiarctic northern Quebec (55°00′N; 69°55′W), one of the three main herds of woodland caribou (Rangifer caribou) of Central Ungava, cross the lake Delorme area. During their annual migration, caribou make many persistent tracks which serve as mosquito larval breeding sites for four species of snowmelt Aedes. There are no appreciable differences in species composition, the relative abundance and the density of the mosquito populations in these tracks, and in the natural shallow pools of the two bog plant associations (Carex oligosperma and Chamaedaphne calyculata) crossed by the caribou trails.