This huge mid-boreal area, known as the Cumberland Marshes, includes all the wetlands between the Carrot and Saskatchewan Rivers, and between Kennedy Lake and the Saskatchewan - Manitoba boundary. The community of Cumberland House is located in the northern section of this area. This site is part of the gently sloping flood plain of the Saskatchewan River and its tributaries. Most of this area is covered by fens that are frequently saturated with water at or near the surface. These largely treeless wetlands are covered by cattails, rushes, reeds, sedges, and scattered willows. Numerous marshy lakes are also found throughout the site.
These vast wetlands contain some of the highest densities of breeding waterfowl in Saskatchewan and provide habitat for many other marsh-nesting birds as well. The only thorough surveys of the entire area were completed in the early 1970s. More recently, data has been collected only for specific areas that are of conservation interest. The surveys in the early 1970s documented globally significant numbers of several waterfowl species using the fens and marshes in both the breeding and non-breeding seasons. Perhaps most notable was an estimate of 72,000 nesting Ring-necked Ducks; this could represent over 10% of the worlds nesting population. Two other bay ducks the Redhead and Canvasback are also found in the Cumberland Marshes in globally significant numbers: 36,000 (about 5% of the worlds population) and 30,000 (over 4% of the worlds population) respectively. A further 19,000 Gadwall (1% of the Canadian population) and 14,000 Common Goldeneye (over 1% of the North American population) nest here as well. Also, the highest breeding densities of Lesser Scaup in Saskatchewan have been recorded at this location.
During migration periods, other waterfowl dominate the scene at the Cumberland Marshes. About 200,000 Mallards have also been recorded here during the fall migration. This is over 1% of the North American population of this abundant duck. When Tundra Swan, which breed in the Canadian Arctic, return south, about 5,000 or 2.5% of the North American population passes through these marshes. Also, several hundred Black Terns concentrate here during the non-breeding season.
Of interest too, is that the now extinct passenger Pigeon once commonly nested in this area and the first sighting of a Eurasian Wigeon in Saskatchewan was made in the Cumberland Marshes.
BirdLife International (2019) Important Bird Areas factsheet: Cumberland Marshes. Downloaded from http://www.birdlife.org on 15/10/2019.