Our Wild Neighbors

American Beaver

Castor canadensis

An established visitor

Image of a beaver, mounted upright on its hind feet, seen in profile with its head facing right, positioned near a white birch.

Description of the animal

  • Canada’s largest rodent.
  • Weighs between 15 and 35 kilograms. The male and female are approximately the same size.
  • Stocky body, black, flat, and scaly tail.
  • Wide, webbed back legs.
  • Small front legs and elongated fingers with claws.
  • Thick, insulating reddish-brown fur covered with long, rough guard hairs.
  • Very long incisors; the many layers of dentine act as a grater.
  • Its body is adapted to underwater life. Under water, the beaver’s eyes are protected by a nicitating membrane while valves block its nostrils and ears. The beaver’s lips meet behind its incisors and prevent water from entering its lungs when it transports branches in water.

Habitat and needs

  • Lives near slow-flowing waterways where it builds a dam and a lodge. In a year, it can fell more than 200 trees. The dam maintains a sufficient water level to protect the entrance to its lodge. That is where it stores food reserves and spends the winter months. In Wood Buffalo National Park, in northern Alberta, many generations of beavers built a dam that now measures 850 metres in length and is visible from space.
  • Eats leaves, buds, twigs, bark, and herbaceous plant material. The beaver is herbivorous. Its preferred food: the trembling aspen.
  • Uses its tail as a rudder when swimming. It leans on it when walking and uses it as a lever when dragging logs.
  • Spends a great deal of time preening its coat to ensure it is waterproof.
  • Is part of a hierarchical society focused on family and centred on the female. The beaver’s family cell is made up of 10 to 12 members on average: two adults, young beavers from the first litter, and kits from the latest litter.

Relationship

  • More than any other animal, the beaver is part of Canada’s history. The pivotal component of the fur trade, the beaver was trapped for its undercoat that was used to make felt hats.
  • Like humans, the beaver transforms scenery. Without its dams, much of the water in forest streams would run without ever stopping. By stopping the water, the beaver creates new ecosystems that are home to a wide variety of plants and animals. These environments are perfect for hunting and fishing.
  • The beaver’s constructions can flood roads, private commercial forests, or agricultural land.
  • When the beaver establishes itself near municipal water intakes, it can endanger human health. For example, it can transmit the protozoa Girardia that causes giardiasis.
  • Beaver meat is tasty.

Living with them

  • If the beaver population becomes too high, trapping during fall months is an efficient solution. Here are a few ways to keep beavers at bay:
  • Ensure the presence of resinous trees (fir and spruce) along shoreline areas.
  • To protect shoreline trees, install metallic wire fencing around tree trunks. Leave at least two centimetres between the trunk and the mesh. Thus, the tree will have sufficient room to grow.

Participating cities where this animal has been seen