Old Wives-Frederick Lakes (SK031)

Old Wives-Frederick Lakes (SK031)

Southcentral Saskatchewan, Saskatchewan

Description du site

Old Wives Lake is a large shallow saline lake situated about 35 km southwest of Moose Jaw, SK. This lake is fed by the Wood River, spring runoff, and seasonal rains: in severe drought years, it can be completely dry. Seasonal fluctuations in water levels have resulted in the development and exposure of extensive mudflats and islands. On the eastern side of the lake there is a sandy, rocky island known as the Isle of Bays (about 5 km from shore).

Frederick Lake is a small basin situated adjacent to the southwest shore of Old Wives Lake. Ducks Unlimited installed a dam on the Wood River near the west end of the lake which helped create a large riparian marsh upstream, and a variable sized and diverse marsh downstream; the rest of the lake has little emergent vegetation.

This IBA is situated within the physiographic setting described as the Chaplin Plain Landscape Area, within the Mixed Grassland Ecoregion. It is situated within the Missouri Coteau, an important and recognized waterfowl production area.

Ownership of lands surrounding Old Wives Lake is a mix of private and Crown lands held under grazing lease (northwards in particular). Private lands are mainly used for crop production (to the south and north). To the west of the lake is a gently sloping salt flat - where a relatively minor drop in water level exposes large areas of mud. The upland portions of these flats, areas flooded for the shortest period of time, are Crown lands used for grazing and hay production.

Oiseaux

During spring migration, Old Wives Lake supports significant numbers of migrating shorebirds: in 1987, a one-day aerial survey yielded a total of 64,392 shorebirds. Spring surveys in 1993 and 1994 also yielded large numbers of shorebirds, with 32,706 and 37,755 individuals recorded respectively. Sanderlings and Baird's Sandpipers are two of the more abundant species.

Although lake specific estimates are not available for all species (totals for Chaplin Lake and Old Wives Lake were often combined), abundances are truly impressive. In 1987, a three-year average for Sanderlings at Chaplin and Old Wives Lakes (combined) was 55,471 birds, and the Baird's Sandpiper population was estimated to be 29,862 individuals. Also in 1987, a two-year average estimated there to be about 29,600 Semipalmated Sandpipers. In 1995, 9,000 Stilt Sandpipers were recorded at Old Wives Lake. American Avocet also use this area in numbers as high as 1,577.

This Lake also provides important breeding habitat for Piping Plovers, a species identified as a nationally Endangered (Committee on the Status of Endangered Wildlife in Canada; COSEWIC) and globally Near Threatened (International Union for Conservation of Nature; IUCN). In 1991, as many as 42 adults were recorded (about 3% of the Canadian Great Plains population at that time). Numbers in subsequent years have fluctuated: 12 plovers in 1993; 27 in 1994; 8 in 1996, and 86 individuals in 2006.

Several colonial waterbirds also nest in considerable numbers: American White Pelicans are the most conspicuous with an average of 1,933 nests (calculated from 7 surveys conducted between 1970 and 1991), along with Double-crested Cormorants where an average of 336 nests was calculated (from 6 surveys between 1970 and 1991). During the breeding season, about 3,000 Franklins Gulls have been observed here, along with numerous Ring-billed Gulls, California Gulls, and Common Terns. Large numbers of waterfowl also make use of this lake as a summer moulting area (> than 20,000 on a regular basis). In the mid-1980s, as many as 63,000 moulting Canvasbacks were recorded at this site.

Enjeux de conservation

Old Wives Lake was established as a Bird Sanctuary on March 9, 1925. The Isle of Bays is also protected by Provincial Wildlife Refuge Regulations under the Provincial Wildlife Act. The north, east, and south shorelines are designated as critical Piping Plover habitat under the Provincial Wildlife Habitat Protection Act.

The North American Waterfowl Management Plan (NAWMP) and North American Bird Conservation Initiative (NABCI) are two key programs that have focused their energies in this area. In conjunction with Reed Lake and Chaplin Lake, Old Wives Lake forms a site of ‘hemispheric importance' in the Western Hemisphere Shorebird Reserve Network (WHSRN)

Over 24,000 ducks (mostly Mallards and Northern Pintails) died at this site in 1970 from an outbreak of avian botulism. In recent years, outbreaks of avian botulism have regularly occurred, and in 1997, an estimated one million birds died.

Catégories ZICO Habitats Usages Menaces Potencielles ou Existantes Status de Protection

• Bécasseau sanderling51 654 (max.)
• Fuligule à dos blanc63 000 (max.)
• Pélican d'Amérique3 866 (max.)
• Bécasseau semipalmé30 404 (max.)
• Bécasseau à échasses9 040 (max.)
• Grue blanche1 (max.)
• Pluvier siffleur42 (max.)
• Oiseaux aquatiques34 292 (max.)