At this sanctuary in 1929 a federal biologist recorded the first eggs and nests of blue phase Snow Geese. The Great Plain of the Koukdjuak contains much wet and dry tundra. Small streams criss-cross wet sedge meadows and marshy tundra. The low lands are dotted with countless ponds and small lakes which are muddy and shallow providing birds optimal water bird habitat. Wide beaches border Foxe Basin, and the tidal flat can be 15 km wide with low relief and a large tidal range.
Some areas are hard to reach so little research has been done in recent years.
At the end of breeding season, from one to two million geese may be present on the Great Plain of the Koukdjuak, including Lesser Snow Geese, Canada Geese, and Brant. The world's largest Lesser Snow Geese colony is found on the Great Plain of the Koukdjuak. Previously, the Lesser and Blue geese were classified as separate species however, blue is now considered a colour phase of the Snow Goose. Blue and White Snow Geese often mate and produce either blue of white goslings and blue usually predominate. Intermediate blue and white geese have been seen.