| IBA |
Île Dickerson
Dundee, Québec |
| Site Summary |
| QC136 |
Latitude
Longitude |
45.036° N
74.586° W |
Elevation
Size |
48 - 52 m
0.82 km² |
Habitats:
coniferous forest (temperate), rivers/streams
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Land Use:
Unknown
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Potential or ongoing Threats:
Disturbance
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| IBA Criteria: Nationally Significant: Congregatory Species |
| Conservation status: Unknown |
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Site Description
Dickerson Island is situated in the St. Lawrence River, downstream from Cornwall, Ontario, near the Ontario/Québec border. Although the island is formed mostly of spoil piles, it is almost completely forested with deciduous trees such as American Elm, maples, Basswood and numerous large hawthorns. The ground is covered with dense ferns and the provincially rare Wild Onion (Allium canadense) is found here.
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Birds
This island has a large breeding population of herons. A Great Egret colony has been increasing in size since its discovery in 1985. On average, 71 Great Egrets were present on the island in the 1990's. This is almost 18% of this species Canadian breeding population and is Canada's largest Great Egret colony. Provincial government biologists plan another survey for 2001.Dickerson Island is one of only two Québec sites with three species of colonially breeding herons. In addition to Great Egrets, Great Blue Herons and Black-crowned Night-Herons also breed on the island. The number of breeding Great Blue Herons peaked in 1992 with 260 pairs (nationally significant), but on average there were 214 breeding Great Blue Heron pairs on the island in the 1990's. In 1992, 50 pairs of Black-crowned Night-Herons bred on the island, but in 1997, none were present.
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IBA Criteria |
| Species↓ T | A | I |
Links |
Date |
Season |
Number |
G |
C |
N |
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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.
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Conservation Issues
Dickerson Island is part of the Akwasasne Indian Reserve. There is a concern that the herony will be disturbed by people.
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