IBA Niagara River Corridor
Niagara Falls, Ontario
Site Summary
ON002 Latitude
43.052° N
79.006° W
74 - 177 m
184.47 km²
Other urban & industrial areas, Cliffs, rocky shores & islets (freshwater), Rivers, Streams
Land Use:
Tourism/recreation, Urban/industrial/transport
Potential or ongoing Threats:
Housing and urban areas, Commercial and industrial development, Renewable energy, Roads and railroads, Dams and water management/use, Domestic and urban waste water, Industrial and military effluents
IBA Criteria: Globally Significant: Congregatory Species, Waterfowl Concentrations, Colonial Waterbirds/Seabird Concentrations
Conservation status: IBA Conservation Plan written/being written
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Site Description
The Niagara River flows 60 km from Lake Erie to Lake Ontario. In addition to being a major tourist destination, it provides drinking water, recreational fishing, employment, and electrical power to millions of people. The river is bordered by urban areas, industrial developments, and agricultural lands with parkland areas and remnant natural areas being interspersed. For a 15 km stretch downstream from the falls the river flows through a 100 m deep and 1 km wide gorge. The riverine habitats are quite varied, ranging from large lake-like areas, exposed boulder beds, rapids, falls, whirlpools, and stretches with swift currents. Within the gorge, the cliff rim, cliff face, and talus slope communities support one of the highest concentrations of rare plant species in Ontario.
The Niagara River annually supports one of the largest and most diverse concentrations of gulls in the world. More than 100,000 individuals can be observed foraging along the river during fall and early winter. A total of 19 gull species have been recorded (60% of all New World gull species), with up to 14 species being recorded on a single day. The number of gulls and diversity of species generally peak in November. Two species occur in globally significant numbers, Bonaparte's Gull and Herring Gull, while Ring-billed Gull nearly reaches 1% ot its respective estimated total global population.

During fall and early winter 10,000 or more Bonaparte's Gulls can regularly be observed along the river (over 2.5% of its global population). Peaks of more than 40,000 individuals have been observed on several occasions (1973, 1977, 1990, 1991, and 2009) representing over 10% of its 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 25% of its 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 about 5% of the North American Herring Gull population with nearly 14% of the population being reported on a single day. Ring-billed Gulls are also present in large numbers, exceeding 20,000 individuals.

Waterfowl concentrations during fall and winter also regularly exceed 20,000 individuals with more than 20 species represented. Canvasbacks and Greater Scaup are occasionally present in significant numbers, or numbers exceeding 1% of their respective estimated North American populations.

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. Due to the regional geography, large numbers of migrating raptors and landbirds cross the river during migration, however they do not stop in large numbers along the river corridor. Lastly, about 20 speciesof birds identified as at risk by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) have also been observed using this area.

IBA Criteria
SpeciesT | A | I Links Date Season Number G C N
Acadian Flycatcher 2016 SU 1
Bonaparte's Gull 1979 - 2019 FA 3,000 - 100,000
Bonaparte's Gull 1996 - 2013 SP 4,240 - 50,000
Bonaparte's Gull 1990 - 2020 WI 3,000 - 70,000
Canvasback 1997 - 2020 WI 4,226 - 14,000
Chimney Swift 1993 - 2019 FA 24 - 200
Chimney Swift 2020 SP 30
Great Black-backed Gull 1998 - 1999 WI 1,540 - 2,089
Greater Scaup 1979 - 1999 FA 7,600 - 15,000
Greater Scaup 2014 SP 6,000
Greater Scaup 1993 - 2020 WI 4,778 - 30,000
Herring Gull 1999 - 2018 FA 3,000 - 40,000
Herring Gull 1979 - 2020 WI 2,800 - 50,000
Little Gull 1990 - 2020 FA 2 - 11
Little Gull 1995 - 2020 SP 2 - 137
Little Gull 1990 - 2020 WI 2 - 23
Loggerhead Shrike 2005 SP 1
Prothonotary Warbler 2016 SU 1
Red-breasted Merganser 2006 - 2015 FA 2,000 - 9,000
Red-breasted Merganser 2014 SP 2,000
Red-breasted Merganser 2000 - 2011 WI 2,500 - 6,000
Red-headed Woodpecker 2012 FA 12
Red-throated Loon 2011 FA 350 - 1,205
Ring-billed Gull 1995 FA 27,000
Ring-billed Gull 1998 SU 32,000
Ring-billed Gull 2009 WI 23,000
Rusty Blackbird 2013 FA 30
Waterbirds 1990 FA 73,594
Note: species shown in bold indicate that the maximum number exceeds at least one of the IBA thresholds (sub-regional, regional or global). The site may still not qualify for that level of IBA if the maximum number reflects an exceptional or historical occurrence.
Conservation Issues
The Niagara River corridor was the first globally significant IBA to be jointly identified by cooperating organizations in Canada and the United States. It was formally dedicated in December 1996.

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.

The IBA Program is an international conservation initiative coordinated by BirdLife International. The Canadian co-partners for the IBA Program are Birds Canada and Nature Canada.
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