Middle Mackenzie River Islands (NT081)

Middle Mackenzie River Islands (NT081)

Fort Norman, Northwest Territories

Site Description

The Middle Mackenzie River Islands IBA site consists of a 250-kilometre stretch of the Mackenzie River and the associated shoreline between Redstone River and a spot 30 km north of Oscar Creek. The small communities of Norman Wells and Fort Norman lie along this piece of mountain-bordered river. Of the many islands on the river, some are flat and sandy, while others are large and rocky. Shoreline vegetation in places consists of sedges, horsetails and willows, or of pondweed and other emergent plants. The forests of low-lying shorelines are a mix of White Spruce and Balsam Poplar whereas forests on higher terraces and levees are dominated by White Birch. In December, Moose often take up residence on the islands, but in March or April they return to the mainland.

Birds

Waterfowl of many kinds stop over on the Middle Mackenzie River islands during spring migration: Snow Goose, Greater White-fronted Goose, Canada Goose, Tundra Swans as well as many duck species. Horsetail and willow catkins are the prime food source.

The species found in the greatest abundance in spring is the Snow Goose of the Western Central Flyway population. The geese arrive in early or mid-May and only stay for a short time. At this time of year there are few good feeding areas, except ones such as those found in the open water and exposed shorelines of the Mackenzie River. It is thought that the majority of the Western Central Flyway population uses the Mackenzie River as a migration route (IBA site NT080 Lower Mackenzie River Islands is part of this route).

In May of 1972, a maximum of 28,600 Snow Geese were counted in one day. In total, it is thought that 95,000 Snow Geese used the Mackenzie River that year. These numbers represent, respectively, 17 and 56% of the Western Central Flyway population, and about 2 and 6% of the global population of Snow Geese. The estimates used to calculate these percentages are from 1976 Snow Goose estimates (current estimates are much higher because the species has grown considerably).

Conservation Issues

Although barges use the Mackenzie River frequently, these transport boats are not known to cause disturbance to the migrating geese. Activities at the oil fields of Norman Wells have included dredging and the creation of artificial islands, but they are thought to have had only minor short-term effects on the geese.

IBA Criteria Habitats Land Uses Potential or Ongoing Threats Conservation Status

• Snow Goose95,000 (max.)
• Rusty Blackbird300 (max.)