Lac Deschênes is a broad widening of the Ottawa River, just to the west of the city of Ottawa, Ontario. The river here is about three kilometres wide. The site is bordered on the east by the Deschênes Rapids, and on the west by Innis Point. The shores are gently sloped and mostly composed of broken limestone interspersed with smaller sections of aquatic shoreline vegetation or mudflats.
This lake is one of the larger bodies of water that waterbirds reach when migrating south from parts of northern Quebec and Ontario. Ring-billed, Herring and Great Black-backed gulls are amongst the most abundant birds seen in the fall. Regularly, between 10,000 and 20,000 gulls are found in this stretch of the river in late October and early November. In the 1980s, up to 30,000 were seen on occasion. Various waterfowl species are also abundant, with often 10,000 to 15,000 Canada Geese present in the fall. On one occasion about 10,000 Mallards were seen in the Shirleys Bay section.
Numerous other waterbirds stop at the lake during their fall migration. Of particular interest are the few hundred Red-throated Loons that pass through. Sometimes as many 500 are seen and once in the 1980s, 3,000 were counted. Amongst other more common dabbling and diving ducks, scoters are found at most about 1,500 are present. Arctic Terns are seen sometimes in spring along with larger numbers of Common Terns. Only moderate numbers of shorebirds are seen here; at most about a thousand concentrate in the muddier parts of the shoreline such as at Shirleys Bay and Andrew Hayden Park, both on the south side of the lake.
There are no islands at which waterbirds could breed, although a small number of Ring-billed Gulls breed on the rocks by the Deschênes Rapids.
BirdLife International (2020) Important Bird Areas factsheet: Lac Deschênes. Downloaded from http://www.birdlife.org on 03/12/2020.