Spruce Island Reef (MB098)

Northern Lake Winnipegosis, Manitoba

Latitude 53.044°N
Longitude 100.587°W
Altitude 253m
Area 48.20km²

Site Description

The Spruce Island Reefs are located in the northern part of Lake Winnipegosis in Manitoba. Lake Winnipegosis is a large (5,403 km²), shallow (maximum depth ~55 m), freshwater lake with many small islands. Deciduous and coniferous forests border Lake Winnipegosis, with large expanses of freshwater marsh occurring along the lake. The habitats of these islands are unrecorded, but are assumed to be as noted here.

Birds

The Spruce Island Reefs support globally significant numbers of Caspian Terns, and a large mixed colonial waterbird colony. Approximately 3,000 Caspian Terns nested on the Spruce Island Reefs in 1999. This represents over 9% of this species North American population, and may be the largest Caspian Tern colony in Canada. Also, over 1% of the estimated Canadian population of American White Pelican also nest on these islands - in 1999, 760 nests were found.

Common Tern, Double-crested Cormorant, Ring-billed Gull, and Herring Gull also breed on the reefs. A 1999 survey found 200 Common Tern nests, 1,351 Double-crested Cormorant nests, 3,498 Ring-billed Gull nests, and 43 Herring Gull nests. Thus, in total 8,852 nests of colonial waterbirds, or about 17,700 birds, breed here.

Conservation Issues

Colonial waterbirds nesting in Lake Winnipegosis face several problems. Some residents whose livelihood depends on fishing feel that the birds, especially cormorants, are eating too many fish. As a result, birds are sometimes shot, or nests are destroyed.

  • Globally Significant:
  • Congregatory Species
  • Nationally Significant:
  • Congregatory Species
  • Freshwater lake
  • Freshwater marsh
  • Unknown
  • Disturbance
  • Hunting
  • No protection
Caspian Tern
Number Year Season
6,0001999Summer
American White Pelican
Number Year Season
1,5201999Summer

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