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and 1.5-2.1 m (4.9-6.8 ft.) high; the walls are 0.6-1 m (1.9-3.3 ft.) thick. The lodge has two or more underwater entrances. It is built in lakes, streams and tidal river deltas, and may be surrounded by water or touch the shoreline; it may include burrows dug into riverbanks. The beaver (Castor canadensis) is not just the largest native rodent in Newfoundland and Labrador – it’s the largest in North America. Beavers are generally nocturnal, although they are sometimes spotted during the day. Their typical diet is bark, leaves, twigs and buds of maple, aspen, birch, poplar and willow trees and alders; and aquatic plants and lily roots. Before the onset of winter, beaver colonies will gather and cache food in deep-water areas near the lodge. They are semiaquatic, are excellent swimmers and can stay underwater for up to 15 minutes at a time.
Beaver benefits The beaver is a keystone species, meaning their activities can affect the entire ecosystem. Beaver ponds provide important habitat for waterfowl, fish and other aquatic life. These ponds increase biodiversity as wetlands are formed and riparian habitats are enlarged. Newly created watery habitats are colonized by aquatic plants; bird, mammal, fish and insect diversities expand in these areas. Stream flow is increased in seasonally dry streams by run-off stored behind beaver dams; some areas may have up to 60 per cent more available water when beavers are present. Beaver ponds also improve stream water quality by removing sediments and pollutants including suspended solids, nitrogen, phosphates, carbon and silicates. Additionally, fecal coliform and streptococci bacteria in the water are reduced. Beaver ponds are typically at or near bank full, so when water levels increase, the banks overflow and spread water and nutrients beyond to a wide zone of streamside vegetation. Waterfowl benefit because beavers create areas of water and help thaw 62
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areas of open water, which allows for an earlier nesting season. The number of ducks in beaver-inhabited areas sometimes increases by 75 per cent over non-beaver influenced areas. Trumpeter swans and Canada geese often depend on lodges for nesting sites. Beavers benefit other birds by removing pondside trees and increasing the height and density of grasses, forbs and shrubs, which enhances nesting cover. Dense willow growth in areas where beavers feed also increases the number of insects, important to many bird diets. As trees drown due to rising water levels, they make ideal nesting sites for woodpeckers. Their work excavating cavities then attracts flycatchers, tree swallows, chickadees, wood ducks, goldeneyes, mergansers, owls and kestrels. Fish eaters such as herons, grebes, cormorants, bitterns, egrets and kingfishers all fish in beaver ponds. Many fish species also benefit from beaver activity, particularly trout and salmon. The presence of dams has shown to increase the number and size of brook, brown and rainbow 1-888-588-6353
