. The Canadian field-naturalist. 1966 Townsend: Waterfowl Nesting EGG LAKE WATER LEVELS 77 87LO Figure 2. Water levels of Egg Lake during the summers of 1962-1964. water levels typically decline progressively during the nesting season (Figure 2). Because much of the immediate shoreline of Egg Lake is floating, its relative wetness does not change significantly with fluctuating water levels un- less the lake is so low that the floating mat comes to rest on the lake bottom. For about 2 weeks following breakup, however, these floating mats are frozen in the ice at lake levels existing the
. The Canadian field-naturalist. 1966 Townsend: Waterfowl Nesting EGG LAKE WATER LEVELS 77 87LO Figure 2. Water levels of Egg Lake during the summers of 1962-1964. water levels typically decline progressively during the nesting season (Figure 2). Because much of the immediate shoreline of Egg Lake is floating, its relative wetness does not change significantly with fluctuating water levels un- less the lake is so low that the floating mat comes to rest on the lake bottom. For about 2 weeks following breakup, however, these floating mats are frozen in the ice at lake levels existing the previous fall. Thus, any major increase in early-spring lake levels would probably flood the immediate shoreline and inundate the floating islands. Waterfowl Arrival Except for the White-winged Scoter (Mela?iitta deglandi), most species were present on the marsh when I arrived (4 May 1963, and 27 April 1964). The only specific observations of ducks recorded for the month of April came from Russell Robertson (Houston and Street, 1959, p. 199), manager of the lease. In 1959 he recorded the following arrival dates: Mallard and Pintail, 5 April; Lesser Scaup, 18 April; Canvasback, 28 April; and Blue-winged Teal, 6 May. By the end of the first week in May 1963, Mallards, Canvasbacks, Golden- eyes, Pintails, Redheads, Gadwalls, and Green-winged Teal were paired and on territories. Scaups and Ring-necks were paired, but still remained in large groups on the lakes. By 20 May these latter species were on territories. Dates of Nest Initiation The histories of 60 nests in 1963 and 96 nests in 1964 were complete enough to backdate to time of nest initiation. No distinction was made between "first nests" and "; The earliest Mallard and Canvasback nesting records were 26 April and 1 May respectively, before ice breakup was complete and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colo
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