North, West, and East Shoal Lakes (MB038)
North, West, and East Shoal lakes are located in the southern part of the Interlake region of Manitoba. The area used to consist of one lake, but in 1912 when the Wagon Creek drain was constructed, the water level fell four to five metres. The lakes are alkaline and contain a number of islands. There are some rocky areas around these lakes and the country surrounding them is generally cattle pasture and is extremely flat. The flat terrain means that fluctuations in water levels significantly affect the presence of different habitats.
The North, West and East Shoal Lakes are highly significant for enormous congregations of migrating waterfowl and high numbers of nesting pelicans, grebes and plovers. As much as 2.3% (1,935 nests) of the estimated global American White Pelican population was recorded at this site. Another significant breeder is the globally vulnerable and nationally endangered Piping Plover. Over six years, between 1985 and 1996 an average of 46 plovers have been recorded in West Shoal Lake (26 in 1996). This average is approximately 1.5% of the Great Plains population.
During the fall migration, vast flocks of Canada Geese and Lesser Snow Geese are observed. Peak one day counts have recorded as many as 100,000 Canada Geese, representing a staggering 30% of the estimated Tall Grass Prairie Canada Goose population and about 200,000 Lesser Snow Geese, representing approximately 6.6% of the estimated Mid-Continental Lesser Snow Goose population. Other waterfowl numbers recorded include over 50,000 ducks of mixed species that were observed on several single day counts. Mallard, Blue-winged Teal, Gadwall, and Tundra Swan are amongst the species present.
Other birds that have been known to breed at this site in small numbers include: Western Grebe (400 nests in 1979), Ring-billed Gull (450 nests in 1986), Herring Gull (232 nests in 1979), Black-crowned Night-Heron (6 nests), Eared Grebe (500 nests), Common Tern (40 nests in 1986), Double-crested Cormorants (263 nests in 1986), Willet and American Avocet.
The breeding populations of colonial nesting species, and to a lesser degree, waterfowl here, are very affected by fluctuating water levels due to dryer or wetter years. The pelicans nesting colonies may be vulnerable to site-specific disturbances such as pesticides. Also, it is possible that Ring-billed Gulls have encroached on Piping Plover habitat.
Potential or Ongoing Threats