Îles de la Paix Migratory Bird Sanctuary

The Iles de la Paix Migratory Bird Sanctuary (MBS) is located south of Montréal, in Québec. It preserves natural habitat for many birds in a very urbanized region.

Importance of the sanctuary: migratory birds and other wildlife

The Îles de la Paix Migratory Bird Sanctuary is located southwest of the Island of Montreal, in a natural widening of the St. Lawrence River called Lac Saint-Louis. In 1972, in order to protect waterfowl, this sanctuary was established in the midst of this very industrialized region, where the shores have been highly altered. This makes the protected area a haven for a wide variety of flora and fauna. A series of wildlife inventories conducted in 2004 by the Canadian Wildlife Service showed that this area supports more than 11 mammal species, 130 bird species, three reptile species and five amphibian species. Life in the waters surrounding the terrestrial portion of the sanctuary is also very diverse with 41 fish species and over 80 invertebrates, including 9 fresh water mussels species.

Many birds use this protected area as a stopover during their yearly migrations. In the spring, nearly 5000 ducks make an appearance within the sanctuary’s boundaries and during the fall migration, an estimated 30 000 birds including greater scaup, common goldeneye and common merganser stop in. Besides being used for resting and feeding, this sanctuary is an important nesting site for many species of birds during the summer months. Nesting species includes many waterfowl species, including:

  • American black duck
  • mallard
  • northern pintail
  • gadwall
  • wood duck
  • green-winged teal
  • blue-winged teal
Mallard. Photo: Jean-François Rail

Several other breeding species can also be observed in the group of islands within the sanctuary, including:

  • tree swallow
  • black tern
  • pied-billed grebe
  • green heron
  • black-crowned night-heron
  • common gallinule
  • spotted sandpiper
  • great horned owl
  • marsh wren

Did you know?

When they migrate, tree swallows often form giant flocks that can number in the hundreds of thousands. When all of these birds begin swirling around together they almost look like a living tornado!


Spanning several kilometres near one of the most important navigable waterways in North America, the Îles de la Paix Migratory Bird Sanctuary encompasses approximately 1100 hectares, overlapping the Îles de la Paix National Wildlife Area. The majority of the islands in this archipelago are included within the boundaries of the sanctuary as are the waters within a 500-metre radius around the islands.

Islands in the Îles de la Paix MBS in spring

These dozen low-lying islands have shorelines that are higher than their centres, creating a distinct succession of plant species from the shore to the middle of the islands that ranges from wetland plain vegetation to swamp vegetation.

The slightly inclined northern shores of the islands are mostly clay with some sandy areas, making them vulnerable to the effects of wave action and spring flooding. Overall, due to their exposure to high water levels and erosion, the shores of the islands have receded causing changes to the composition of the habitats on the islands. Today, tall grass prairies and forests are the main habitats found on the islands. Marsh surrounds the islands, particularly on the south shores of the archipelagos.

Habitats vary slightly according to their placement within the archipelago and the individual topography of each island. The westernmost islands are dominated by forests of red and silver maple with scatterings of reed canary grass, rice cutgrass and purple loosestrife as well as a shrub layer composed of common buttonbush, common winterberry and staghorn sumac.

The islands on the eastern side of the archipelago have forests growing at the higher elevations, which tolerate water level variations. Herbaceous meadows grow at the lower elevations with many species of plants common to such wet environments such as giant bur-reed, common cattail and broadleaf arrowhead.

In the southern part of the archipelago, the islands are sheltered from winds and currents, promoting the growth of floating aquatic plants, such as:

  • tuberous water lily
  • Canada waterweed
  • tape grass
  • water star-grass
  • nitella
  • duckweed

Map of the area

Map of Îles de la Paix MBS
  • Long description

    Map showing the region surounding Beauharnois and Léry, in Québec. The boundaries of the Iles de la Paix Migratory Birds Sancutary (MBS) and those for the Iles de la Paix National Wildlife Area (NWA) are shown on the map. The MBS covers most of the Iles de la paix and the surounding waters. The MBS overlaps the NWA, but also spreads in the surrounding waters. Both protected areas are located west of Léry and north-west of Beauharnois and from road 132. The scale of the map is in kilometers. Permanent waters,  and road are shong on the map. An inset shows the location of the shelter in Canada.

Access to the sanctuary

Migratory Bird Sanctuaries, such as Îles de la Paix, are established across the country to protect migratory birds during critical periods of their migration. Whether these areas are used for feeding, resting or nesting, they play an important role in the survival of many species. Please ensure that you are aware of how you can help protect this sanctuary and please read the restrictions, including those on firearms and hunting, which are in place to conserve the wildlife that call it home. It is also important to remember that pets are not welcome inside Migratory Bird Sanctuaries.

If you would like further information on what is permitted in Migratory Bird Sanctuaries, please visit the Management and Activities section of the website. For more information on Îles de la Paix Migratory Bird Sanctuary in particular, please contact our regional office.

Key facts about Îles de la Paix Migratory Bird Sanctuary

Protected Area designation Migratory Bird Sanctuary
Province or territory Québec
Latitude/longitude 45° 21' N 73° 50' W
Size 1092 hectares
Date created (Gazetted) 1972
International Union for Conservation of Nature (IUCN) management category Natural Monument or Feature (III)
Additional designations Overlaps with Îles de la Paix National Wildlife Area (NWA)
Part of the Lac Saint-Louis Important Bird Area and the Îles de la Paix National Wildlife Area
Main habitat type Flooded forests and marsh
Key bird species Mallard, pied-billed grebe and tree swallow
Other species Birds: American black duck, northern pintail, green-winged teal, blue-winged teal, black tern, American bittern, common gallinule, spotted sandpiper, great horned owl, marsh wren, great blue heron, greater scaup, common goldeneye, common merganser, green heron
Plants: Reed canary grass and giant bur-reed
Amphibians and reptiles: Painted turtle, leopard frog and spring peeper
Listed species under the Species at Risk Act (SARA) The sanctuary is home to at least three species that are at risk under the Species At Risk Act and others are classified as threatened or vulnerable or likely to be so designated under the Quebec Act respecting threatened or vulnerable species.
Management agency Canadian Wildlife Service, Quebec Region

Related links

Îles de la Paix Migratory Bird Sanctuary on Google Maps (Please note that the Google map is a complementary source of information and does not represent the official map or site name)

Contact information

Environment and Climate Change Canada – Quebec Region
Canadian Wildlife Service
Protected Areas Unit
801-1550, avenue d'Estimauville
Québec, Quebec G1J 0C3

Toll-free: 1-800-668-6767 (in Canada only)
Email:  ec.enviroinfo.ec@canada.ca

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