Beavers
The beaver is Canada's largest rodent. On average, it can grow to weigh between 16 to 32kg and measure 60 to 80 centimetres in length.
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Urban Wildlife Watch - Beavers |
The beaver has a thickset body covered with dark, reddish brown fur. Beaver fur consists of coarse guard hairs over dense, soft under-fur.
Beavers have large incisors that never stop growing; this is so the beaver may chew through hundreds of trees without wearing its teeth out. Gnawing keeps the teeth sharp.
The front paws are smaller then the back and designed for grabbing and carrying sticks, mud and other matter for building or eating.
The small eyes on a beaver have nictitating membranes, which can be drawn across the eyeball while underwater without the beaver losing vision. A beaver's ears, nose and mouth can also be closed off to prevent water entry.
Beavers are semi-aquatic mammals. Their large mass to surface ratio and dense insulated fur make it possible for beavers to live in ice-cold water.
Beavers have a horizontally flattened and paddle-shaped black tail, which has a scaly texture. The tail is used for balance on land and steering in the water. Large hind webbed feet propel the beaver. These features make it an exceptional swimmer. They have the ability to hold their breath for 15 minutes under the water. Although graceful in water, beavers waddle ungainly on land.
Behaviour
Beaver residences can be in a lodge or on the banks of creeks and ponds. Creek beavers will dam up running water and create beaver ponds. These ponds are an important habitat for wildlife, creating more homes and feeding areas. Beaver ponds also assist in stabilizing water tables and help prevent rapid water run off. The lodge and dams are both constructed with sticks, trees, grass, rocks and mud. The lodge entrance is under the water; beavers swim up into the hollow inside. Due to this structure, and the fact the beaver's main predators (coyotes, wolves and bears) have a difficult time accessing it.
Because of this instinct to back up water, the beaver can cause problems for humans. Flooding of crops, industrial property and residential land may occur as a result of beaver dams.
The beaver's habitat not only protects it from predators, but also the winter elements. Having deep enough water so the beaver can travel under the ice to food plots and surface holes is very important for its winter survival.
Beavers can be very territorial with other beavers and may fight to protect their pond. Although they will not purposely go after a human, making them feel threatened or trapped could result in an aggressive attack. If they are threatened in the water, they will slap their tail warning other beavers of danger, before diving under the water. If cornered on land the beaver may hiss, lunge and use intimidation to frighten off the aggressor.
After a three month gestation period, the beaver will have four to six young between April and June. The kits will spend the next two years with the mother, learning and babysitting next year's offspring. The family of beavers will spend most of their time doing maintenance around the pond, fixing dams and managing water levels, as well as keeping the lodge structurally sound. After two years, the juvenile beavers are expelled from the colony and migrate in search of a mate and residence.
Management
Managing beavers can be difficult. However, there are some ways one can try to prevent beaver problems.
Always assess the problem objectively. It may be resolved with minimal effort.
If flooding is the concern, releasing small amounts of water from the dam may resolve the issue. If the beaver is damming up a culvert, try a mesh guard. The guard should extend off the culvert to increase the area in which the beaver must dam.
If logging is the concern, protect the trees by wrapping chicken wire or galvanized steel around the base of each tree to a height of one metre.
If the issue persists, removing the beavers by trapping or shooting may be required.
Further information
Transportation and Agriculture Services
780-417-7100 (24 hours)
Last updated: Tuesday, May 17, 2011
Page ID: 3482