Red Knots & Semipalmated Sandpipers

Delta Marsh

Country: Canada

Region: Manitoba,

Nearest city/town: Portage La Prairie

Site: Delta Marsh

Species/Sub-species: REKN-rufa

Total biogeographic population: 2,500

Count Method: Total estimate

Count: 5001

% biogeographic pop. at site: 1.19

Season (primarily): Summer

Site recognition: Ramsar

Site description: This site is situated in the Lake Agassiz Basin at the southern edge of Lake Manitoba in the Province of Manitoba, 22 km north of Portage la Prairie. Using the Ramsar Classification System for Wetland Type, the site's habitat characteristics are wetlands (inland), including lakes (inland wetlands: Type O - permanent freshwater lakes, and Type Tp - permanent freshwater ponds, marshes and swamps). Delta Marsh consists of large basins and small sloughs connected to Lake Manitoba by several natural beaches. Land ownership is a combination of provincial Crown land and private land. About 16 600 ha are in public ownership as provincial Crown lands administered by the Wildlife Branch of the Manitoba Department of Natural Resources. 2 000 ha of this area are protected as a game bird refuge and 7 700 ha as public shooting grounds. The Delta Waterfowl Research Station controls a further 1 600 ha of the marsh. The remaining land is under private ownership. The provincial Crown land of this site is designated as Heritage Marsh. Permanent research programs have been conducted since 1938 by the Delta Waterfowl Foundation at the Delta Waterfowl Research Station, dealing mainly with waterfowl ecology and behaviour and by the University of Manitoba since 1967, whose research has concentrated on plant ecology, hydrology and local history. Over 100 publications in journals have resulted. Ducks Unlimited Canada has been a cooperator in many of the research programs. Both the Delta Waterfowl Research Station and the University of Manitoba have public education facilities. Public access to the Marsh is not restricted and is available at numerous points on the perimeter of the Marsh.3

Known threats: The site is designated as a Heritage Marsh. In terms of threats from site land use change, the privately-owned west portion of the marsh is periodically flooded by the Portage Floodway, causing excessive siltation and vegetational growth. The physical alteration of the site is also a threat due to the hybrid cattail Typha sp. x gluaca, which is now the dominate cattail species. It is highly invasive and out-competes the native Typha latifolia and occupies habitats unsuitable for Typha latifolia.3

Notes: The definition of the sub-sites follow WHSRN boundaries2.

Sources: 1Andres, B.A., P.A. Smith, R.I.G. Morrison, C.L. Gratto-Trevor, S.C. Brown, and C.A. Friis. 2012. Population estimates of North American shorebirds. Wader Study Group Bulletin 119(3): 178-194. 2WHSRN 3