Beaverhill Lake

Location

Alberta, Canada

Category

Regional

Basis for Designation

More than 20,000 shorebirds annually.

Size

14,310 hectares (35,360 acres)

Date Designated

May 1996

Site Owner

Government of Alberta​

Site Partners

Ducks Unlimited Canada
Beaverhill Bird Observatory
Canadian Wildlife Service

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Overview

This large, natural, inland lake is strongly alkaline and quite shallow with a maximum depth of 2-3 meters. With water levels raising in recent years, the lake  one again fills through surrounding creeks and spillover from Lister Lake and drains though a creek in the north end to the North Saskatchewan River . Lister Lake attached to the south end of Beaverhill Lake is controlled by a weir constructed by Ducks Unlimited Canada and could be described as man-made or at least as a man-controlled basin. Water levels are influenced by precipitation and snow melt,  creating exposed mudflats as water levels recede.. The topography of the surrounding area is flat to gently rolling with open grasslands (used as grazing areas for cattle) with a mix of aspen groves and willow stands. The shoreline is variable and includes shallow mudflats, narrow sandy beaches, and areas of dense emergent vegetation.

The maximum count of shorebirds using the site in the spring of 1989 was 23,442 individuals (only select portions of the area were counted because of logistical conditions so this figure does not represent the total lake). In the spring of 1995, the complete lake and adjacent wetlands were surveyed several times. The highest one-day count of 52,334 shorebirds was observed on May 24, 1995. This does not take into consideration turnover rate of individual species.  Therefore, the total number of shorebirds using the lake is probably higher. In 2023, a 5 km stretch of the south shore of Beaverhill Lake was surveyed multiple times. The highest single-day total of individuals was May 7, 2023 with 12,472 shorebirds, comprised primarily of Long-billed Dowitchers. Again, this number doesn’t reflect the numbers for the entire lake.

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Weir at Beaverhill Lake looking north. Photo: Geoff Holroyd.

The lake is used by local breeding shorebirds such as the American Avocet and Piping Plover, but the greatest use is by the arctic nesting shorebirds during migration in the spring. Surveys and general observations, from 1978-1995 and 2023-2024 show that migration use, for most shorebird species, is higher during the spring period of mid-May through the first week of June. A few species, such as the dowitchers, appear to use the area in higher numbers during the fall period which extends well into late September. Shorebirds use the lakeshore, adjoining wetlands and flooded uplands for feeding and roosting. Some of the larger species of shorebirds also use the adjacent cultivated uplands for feeding.

The lake is a major staging site in the spring for migratory geese and swans, as well as a molting and staging area for ducks in the summer and fall (such as Mallard, Anas platyrhynchos, Northern Shoveler, Anas clypeata, Green-winged Teal, Anas crecca, and Canvasback, Aythya valisineria). Numerous species of raptors, including the federally endangered, Peregrine Falcon are observed in association with the large concentrations of migratory birds. Large concentrations of colonial nesting birds have been recorded on the lake’s northern islands. The aspen groves adjacent to the lake provide important habitat for concentrations of neotropical migrants which are monitored by the Beaverhill Bird Observatory. The adjacent grasslands and woodland habitats are also important to a variety of mammalian and avian species.