Thedford Flats

Country/territory: Canada

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

Area: 1,000 ha

Birds Canada / Nature Canada

Site description
The Thedford Flats are located near the Lake Huron shoreline in northwest Lambton County, about 10 km north of Thedford, and 10 km south of Grand Bend. Pinery Provincial Park borders the west side of the site. At one time this area was a shallow bay and marsh that was cut off from Lake Huron by the formation of 30 metre high dunes on the east side of what is now Pinery Provincial Park. In 1875, a canal was cut through the dunes to drain the marsh, and the last remnant (Lake Smith), was drained circa 1959. At present, the flats must be drained with pumps in the spring. Potatoes and onions have been grown here, but in recent years the crops were primarily corn and beans.

Key biodiversity
Since at least 1970, Tundra Swans have congregated at the Thedford Flats during late March. Peak one-day counts have been recorded regularly since the early 1980s, and the long-term average (1983 to 1998) is just over 7,600 birds. A more recent average (1993 to 1998) is 10,800 birds, which is almost 6.5% of the North American Tundra Swan population, and about 12.5% of the estimated eastern population. The maximum one-daycount was recorded in 1994, when 16,356 birds were tallied. Since these one-day counts consider turnover rates, he number of swans moving through the site during the entire spring migration is likely much larger.

Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Thedford Flats. Downloaded from on 19/08/2022.