Lesser Slave Lake PP

Country/territory: Canada

IBA Criteria met: A4i (2008)
For more information about IBA criteria please click here

Area: 200,000 ha

Birds Canada / Nature Canada

Site description
The massive Lesser Slave Lake in northcentral Alberta, is one of the largest lakes in the province. The town of Slave Lake is near the southeastern corner, and several small communities are located along the highway that runs along the south shore. The northern shore of this relatively shallow (20 m) lake is steeper and often rockier than the shallower southern shore, which contains various marsh communities. Sandy beaches and dunes are found at the eastern end of the lake. In Lesser Slave Lake Provincial Park (at the eastern end of the lake) and all around the lake, are hilly mixedwood forests of Trembling Aspen, Balsam Poplar, Balsam Fir, White Spruce and Black Spruce. Two Alberta subregions are represented here: Central Mixedwood and Lower Foothills. At the western end of the lake there is a rich delta leading into Buffalo Bay. Both marsh and swamp habitats are represented here.

Key biodiversity
This diverse area is host to over 200 species of birds, both landbirds and waterbirds. On Lesser Slave Lake itself, up to 3,500 swans occur in spring and fall. Since only a small portion (or none) of these are likely to be Trumpeter Swans, this number must represent between 1 and 2 % of the North American population of Tundra Swans. Depending on water levels, in some years, the swans can be found all along the south shore, while in other years they concentrate in certain locations, including Nine Mile Point and The Flats near Widewater. Other waterfowl are abundant during migration. In the delta at the west end of the lake, thousands of ducks congregate in the fall. Large numbers of Western Grebes, perhaps the largest in the province, nest in several places along the lakeshore there are records of 400 nests at Assineau Point, 200 nests at Driftpile Point and 50 nests at Giroux Bay.

During the breeding season, numerous other waterbird species are found here. Common Goldeneye, Mallard, Common Merganser, Bufflehead, Black Tern, Common Tern and Forsters Tern are just some of the regular breeders. The lake and its associated shoreline provide excellent habitat for breeding Bald Eagles and Ospreys. In August 1997, a survey of the lake and nearby shorelines produced an estimated 72 Bald Eagles.

The forests are rich in breeding forest birds. Some of the most abundant species are Lincolns Sparrow, Tennessee Warbler, Mourning Warbler, Rose-breasted Grosbeak, Yellow-bellied Sapsucker and Magnolia Warbler. In all, 20 species of breeding warblers have been recorded in Lesser Slave Lake Provincial Park. During migration, good concentrations of songbirds move between the eastern edge of the lake and Marten Mountain. Lesser Slave Lake Bird Observatory, established in 1994, has banded many neotropical migrants. The five most commonly banded species are American Redstart, Least Flycatcher, White-throated Sparrow, Alder Flycatcher, and Yellow-rumped Warbler.

Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Lesser Slave Lake PP. Downloaded from on 07/10/2022.