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Location Canada, Manitoba
Central coordinates 98o 15.14' West  50o 10.49' North
IBA criteria A4i, A4iii
Area 31,000 ha
Altitude 247 - 250m
Year of IBA assessment 2008

Bird Studies Canada/Nature Canada

Site description Delta Marsh is a large wetland comprised of wide shallow bays, sloughs and meadows. It stretches westward from St Laurent to Lynch Point along the southern end of Lake Manitoba. The marsh is separated from the lake by a sand ridge covered with deciduous trees including green ash, Manitoba maple, hackberry, willow and cottonwood. The hackberry stand is the northernmost location for this species within Manitoba. The ridge and associated deciduous forest acts as a natural migrational corridor for landbirds migrating to and from the boreal forest and aspen parklands to the west of Lake Manitoba. The 17,000 ha marsh is one of the largest of several marshes in the Lake Manitoba basin.

Key Biodiversity Large numbers of both diving (Canvasback, Redhead, Lesser Scaup) and dabbling (Mallard, Gadwall, American Wigeon, and Northern Pintail) ducks stage in the marsh each fall. Up to 100,000 waterfowl have been detected during aerial surveys (no aerial surveys have been completed since 1991). The number of geese using the site has increased from historic levels with Canada Geese and Snow Geese staging here in large numbers during both spring and fall migration. Ruddy Turnstones congregate in large numbers, such as 1,000, on June 2, 1993.

Large numbers of landbirds also make use of the site. Some indication of the significance is reflected in the banding totals reported by the Delta Marsh Bird Observatory. Between 1995 and 1997, the number of landbirds banded in a single season ranged from 7,500 to more than 9,000 individuals suggesting even higher (much higher) totals of birds migrating through or breeding in the area. In 1996, a total of 3,000 Yellow Warblers and 1,100 Tennessee Warblers were banded. More than 300 individuals of several other landbird species (Yellow-rumped Warbler, American Redstart, White-throated Sparrow, Least Flycatcher, Ruby-crowned Kinglet, Common Yellowthroat, and Song Sparrow) are also regularly banded each season. Up to 50,000 Tree and Bank swallows have been estimated during daily censuses.

Concentrations of over 1000 Western Grebes during migration (1996) and over 1000 pairs breeding (1979), and over 1000 Franklin Gulls have also been observed.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Snow Goose Anser caerulescens passage  1995  1,000,000 individuals  A4i  Least Concern 
Western Grebe Aechmophorus occidentalis breeding  1979  1,000 breeding pairs  A4i  Least Concern 
A4iii Species group - waterbirds passage  1979-1995  100,000-499,999 individuals  unknown  A4iii   

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Delta Marsh Wetlands of International Importance (Ramsar) 23,000 protected area overlaps with site 24,000  
Lake Francis Wildlife Management Area 6,416 protected area overlaps with site 240  
Portage Community Pasture 5,837 protected area overlaps with site 660  
Portage Regional District Park 5 protected area overlaps with site 650  


IUCN habitat Habitat detail Extent (% of site)
Shrubland Scrub  -
Wetlands (inland) Fens transition mires & springs; Freshwater marshes/swamps  -

Land use

Land-use Extent (% of site)
agriculture minor
nature conservation and research minor
hunting major
tourism/recreation major

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Delta Marsh. Downloaded from on 26/10/2016

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