Year of compilation: 2001
During fall and early winter 10,000 or more Bonaparte's Gulls can regularly be observed along the river (over 2% of global population). Peaks of more than 40,000 individuals have been observed on several occasions (1973, 1977, 1990, 1991) representing over 8% of the global population. Over the course of the fall and early winter season up to 100,000 birds have been estimated to pass through this site (over 20% of the global population).
Herring Gulls are also abundant; 20,000 or more individuals can be observed regularly with a maximum of 50,000 individuals being reported on a single day. This represents the regular occurrence of almost 6% of the North American Herring Gull population (ssp. smithsonianus) with upwards of 14% of the population being reported on a single day. The national threshold for Ring-billed Gulls is also regularly exceeded during spring migration.
Waterfowl concentrations during fall and winter also regularly exceed 20,000 individuals of more than 20 species. At least two species (Canvasbacks and Common Mergansers) are regularly present during late fall and early winter in numbers just above 1% of their estimated North American populations; Greater Scaup are occasionally present in significant numbers, and Common Goldeneyes are regularly present in numbers approaching the 1% threshold.
Due to the regional geography, large numbers of migrating raptors and landbirds cross the river during migration. Normally they do not stop in large numbers along the river corridor. Some specific sites along the river corridor are also significant for colonial nesters such as Black-crowned Night Herons, Common Terns, and Ring-billed Gulls.
There is no comprehensive protection for the Niagara River Corridor. Currently, toxic pollutants remain one of the largest potential threats. As such, the Niagara river is targeted as an Area of Concern under the Great Lakes Remedial Action Plan, and is the focus of the Niagara River Toxics Management Plan. Substantial reductions of key pollutants have been achieved at several point sources along the river.
The corridor comprises several municipal jurisdictions and the pressure for urban development is high. Retention of natural habitats and land use planning will be important. Little is known about the food or other ecological resources that support these large populations of gulls. A conservation plan for this IBA is being developed through a coalition of interested groups.
BirdLife International (2021) Important Bird Areas factsheet: Niagara River Corridor. Downloaded from http://www.birdlife.org on 22/01/2021.