Metiskow and Sunken lakes are two small shallow lakes in central eastern Alberta. Metiskow Lake (an unofficial name for an unnamed lake) is just north of the community of Metiskow, while Sunken Lake is to the south. The town of Provost is about 30 km to the east. These lakes are permanent hyper-saline lakes surrounded by native sandy aspen parkland and some cultivated land. The 10 and 30 m wide beaches where Piping Plovers nest on Metiskow Lake have extensive alkali deposits and soft muddy patches, and the isolated gravelly beaches of Sunken Lake are over 30 m wide. Sunken Lake is so named because it sits in a local depression. Scratch grass (Muhlenbergia asperifolia), a rare plant in Alberta, occurs at this site. This is one of only a few (approximately 6-20) occurrences in the province.
The Metiskow and Sunken lakes support globally significant numbers of two shorebird species during spring migration. In 1988, an impressive 10,000 Bairds Sandpipers and 2,000 to 3,000 Sanderlings were recorded. This is between perhaps 3 and 7% of the global population of Bairds Sandpipers and about 1% of the North American population of Sanderlings. The largest mixed species shorebird flock seen was a flock of 17,703 individuals in 1988. Spring surveys in late of 1995 and 1996 recorded relatively low numbers of shorebirds: 2,336 on May 27, 1995, and 905 on May 23, 1996 at Metiskow Lake, and 25 at Sunken Lake on May 23, 1995. These surveys may not have hit peak migration periods, or these years may have been years when the water levels were not ideal for shorebirds. Naturally fluctuating water levels means that only in some years are shorebird numbers notable.
Good numbers of Semipalmated Sandpipers have also been recorded here. In 1988, 6,500 Semipalmated Sandpipers were recorded at Metiskow Lake, and 4,000 were recorded at Sunken Lake. Other shorebirds recorded at Metiskow and Sunken lakes during spring migration include White-rumped Sandpiper (750 in 1988), and Semipalmated Plover (64).
A small number of nationally endangered Piping Plovers breed at this site. Annual counts range from one to eight adults at Metiskow Lake (1987-1991) and three to seven adults at Sunken Lake. Most recently, in 1998, there were two adults at Metiskow Lake and four adults at Sunken Lake.
The adjacent sandy parkland habitat hosts an interesting assemblage of breeding birds, including Lark Sparrow, Spotted Towhee, Hermit Thrush, and Yellow-rumped Warbler. The nationally endangered Whooping Crane has also been recorded at Sunken Lake.
Both petroleum exploration and cattle-grazing have increased noticeably in the last two decades in the area. Natural drought is frequent here, and as with other shallow prairie lakes, these lakes are sometimes completely dry.
This area is considered an environmentally significant area by the provincial government. Metiskow Lake is also a potential regional WHSRN (Western Hemisphere Shorebird Reserve Network) site.Catégories ZICO Habitats Usages Menaces Potencielles ou Existantes Status de Protection
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