Located on the south shore of the St. Lawrence River estuary, this IBA lies in front of the town of Montmagny, at the mouth of the Sud River, about 70 kilometres east of Quebec City. Most of the area is a brackish tidal wetland. Sedimentation at Montmagny Bay has resulted in the formation of extensive mud flats, while scirpus salt marshes are found on both sides of the Sud River. Other aquatic plant communites are dominated by bulrush but include Wild Rice and several species of arrowleaf. The herbaceous vegetation is comprised of a variety of species such as Giant Bulrush, Giant Bur-weed, Cord Grass, Smoke Weed, Purple Loosestrife and other grasses and sedges. American Shad can be found in the salt marsh, while American Eel migrates to the south in the St. Lawrence estuary.
The most noteworthy species found at Montmagny is the Greater Snow Goose (subspecies atlanticus). The greatest numbers are present in fall migration when at least 5,000 birds are regularly present (about 1% of the subspecies’ population). In some years, however, much higher numbers can be recorded, such as in 1997, when a flock of 50,000 were seen. typical numbers?
In 1977, 125 Black-crowned Night-Herons were counted, but the colony seems to have declined since then. Of the many shorebirds that occur here, only Semipalmated Sandpiper has been seen in significant numbers, with over 15,000 counted in the fall of 1980. More recently in 1990, 11,900 were recorded. The second most common shorebird is the Lesser Yellowlegs, with maximum counts of 250 birds. Other regular shorebirds are Greater Yellowlegs, Semipalmated Plover, Killdeer, White-rumped Sandpiper and Least Sandpiper.
Surveys over the years have recorded numerous dabbling ducks, with the commonest being Northern Pintail (maximum count of 3,500). Other common species are Green-winged Teal, Common Eider and Greater Scaup, while American Black Duck, Mallard, Blue-winged Teal, Oldsquaw and Ring-necked Duck occur in smaller numbers. The salt marsh of Montmagny is part of a section of the St. Lawrence estuary that was classified as a waterfowl concentration area.
Four species that are nationally at risk have been sighted here, albeit in low numbers: Harlequin Duck (endangered eastern population), and Short-eared Owl (Special Concern), Red-shouldered Hawk (Special Concern) and Peregrine Falcon (Special Concern). In addition, Least Bittern (Special Concern) is present during the summer in the freshwater marsh, suggesting that there might be a nesting pair.
BirdLife International (2022) Important Bird Areas factsheet: Montmagny. Downloaded from http://www.birdlife.org on 20/01/2022.