Site Complet

Riverton Sandy Bar (MB091)

Recherche

Riverton Sandy Bar (MB091)

Riverton, Manitoba

Latitude 51,005°N
Longitude 96,890°O
Altitude 218m
Superficie 18,24km²

Description du site

The Riverton Sand Islands are located off the western shore of Lake Winnipeg near the community of Riverton (directly west of Hecla Island). They consist of a series of three small islands extending between Riverton Marsh eastward toward Sand Point on Hecla Island. The islands are comprised of sand and gravel that has been partially colonized by grasses and willows. The closest island is located only 50 metres from shore and is connected to the mainland by a sandbar during low water years. Sand Point on Hecla Island is also included within this site.

Oiseaux

This site supports significant concentrations of Ring-billed Gulls and Common Terns. About 1% (10,000 nests) of the world's estimated Ring-billed Gull population were present in 1991. In addition, a total of 800 Common Tern nests, or about 2% of the estimated North American population were present on Sand Islands #2 and #3. Nesting Herring Gulls were also present, with 153 nests being recorded in 1991. The Sand Point on Hecla Island is also noted as a major roost site for pelicans, gulls and terns.

There are also occasional records of nesting Piping Plovers (nationally endangered and globally vulnerable) on the Riverton Sand Islands and on the adjacent Hecla Island Sand Point. During the 1991 International Piping Plover census one pair of Piping Plovers was recorded at each site, while during the 1996 International census only a single pair of Piping Plovers was recorded at the Hecla Island Sand Point.

In addition to the importance of these islands and sandspits to nesting birds, they are also heavily used by several species during migration. The area is reportedly a major concentration site for migrating Canada Geese and Snow Geese although the numbers have not been documented. It has also been reported that hundreds of migrating Sanderlings use the site along with lesser numbers of Ruddy Turnstones and other shorebirds.

Enjeux de conservation

In some years the islands closest to shore are accessible to all-terrain vehicles, and the birds leave the islands if they are repeatedly disturbed. In most years, however, the water levels are deep enough to prevent this from happening. The artificially high water levels that are maintained by he provincial government, however, lead to less shoreline for the Piping Plovers and increased erosion. There is also some desire to develop this site for ecotourism, which could increase the level of disturbance, but might also lead to more vigilant protection. The continued suitability of these islands for nesting colonial waterbirds depends on the suitability of habitat conditions. Important natural forces include water currents, and ice scouring, which removes colonizing vegetation.

Catégories ZICO Habitats Usages Menaces Potencielles ou Existantes Status de Protection
Quiscale rouilleux
Nombre Année Saison
382016Automne
502014Automne
Goéland à bec cerclé
Nombre Année Saison
1702012Été
20 0001991Été