Upper Qu'Appelle Valley, Saskatchewan
Eyebrow Lake lies in the upper QuAppelle Valley, near the town of Tugaske, Saskatchewan. The lake, which is 9 km long and approximately 1 km wide, lies parallel to the QuAppelle River. Historically, the site consisted of a large wetland along the floodplain of the river. However, in 1968, a major water management project was implemented to offset the effects of periodic drought. Five separate basins were established, using dykes, to allow the water levels within the marsh to be controlled. Since the completion of this water management project, Eyebrow Lake has become one of the regions most significant permanent marshes. The marsh is characterized by abundant emergent growth, with bulrush and cattail being the predominant species.
In 1994, two nesting colonies of Black-crowned Night-Herons were present at Eyebrow Lake. In total fifty nests were observed, which represents about 1% of the Canadian Black-crowned Night Heron population. Large numbers of Franklins Gulls also nest at the site, with as many as 2,000 pairs being recorded in 1992 (this represents just under 1% of the worlds population; no estimates are available for the national population). Other nesting species include Eared Grebes (250 pairs), American Avocets (30 nests May 1993), Lesser Scaup (100), substantial populations of Marsh Wren and Common Yellowthroat, as well as smaller populations of Sedge Wren, Le Contes Sparrow, and Nelsons Sharp-tailed Sparrow. Two pairs of Ferruginous Hawks, a nationally vulnerable species, nest near the edge of the lake, and there are historical records of nesting Burrowing Owls (a nationally endangered species). In 1994, a pair of Cattle Egrets nested at Eyebrow Lake, marking the second provincial nest record for this species. As of 1996, 173 species of birds had been identified at Eyebrow Lake. In addition to being significant for nesting birds, Eyebrow Lake is also a very important summer moulting and fall staging area for waterfowl and shorebirds. Approximately 3,000 to 5,000 moulting waterfowl have been recorded during the summer months, with the most abundant species being Mallards, and Northern Pintails. During early May, large numbers of Gadwall (400) and Ruddy Ducks (275) have also been recorded. Shorebirds are also present in relatively large numbers during both the spring and fall migration, with the main species being Short-billed Dowitchers (450 August 1991), dowitcher species (1,000 May 1981), Willet (100 May 1991), and Spotted Sandpipers (40 June 1990).
Avian botulism is one of the most severe threats facing the birds at Eyebrow Lake. Between 1988 and 1992 an average of 2,671 ducks (mostly dabblers) died each year. The worst outbreak occurred in 1991, when 4,790 botulism-infected ducks were found.
Eyebrow Lake is currently managed by Ducks Unlimited. Over the last 30 years the site has played an important role in waterfowl management. In 1969, the Nisku Project was initiated at Eyebrow Lake, to help re-establish the large prairie form of Canada Geese into Saskatchewan. Goslings were raised at the lake, and then were placed in marshes, lakes and ponds across the province. The project ended in the early 1980s, after the species was well established throughout the southern prairies.Catégories ZICO Habitats Usages Menaces Potencielles ou Existantes Status de Protection
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