paperclip beaver

Beavers

Biology

  • Beavers are generally not a threat to human health or safety.
  • They live throughout Canada and most of the United States, though are absent from the most arid regions.
  • They are semi-aquatic, fur bearing animals and the largest of all North American rodents. They are able to remain submerged for as much as fifteen minutes.
  • They are herbivores, feeding on the inner layer of the bark of woody plants (the cambrium), leaves, shoots and aquatic herbs such as duckweed, water lilies and pondweed. Occasionally, they eat the fruits of terrestrial plants, some herbaceous forest plants and even crops such as the soybeans and corn. Evergreen trees are rarely eaten.
  • In the fall, beavers sink large accumulations of branches into the mud close by the lodge. This cached food provides them with winter food supplies.
  • Mature beavers normally weigh 40-60 pounds (occasionally large adults may reach 100 pounds or more) and are 25-30 inches long from the nose to the base of the paddle-shaped tail.
  • The flat, scaly tail is 6-8 inches wide and 10-12 inches long. It is used as a rudder and for propulsion in swimming, and is slapped against the water surface as a danger signal. On land, a beaver uses its tail as a brace when cutting trees and for balance when holding or carrying material with its front paws.
  • Beavers produce one litter (three to four kits) per year, usually between March and June. After weaning, the female and male share parental duties. Earlier young that have remained with the family also assist them. The older young usually leave the area of birth by their second birthday (dispersion). Dispersing beavers usually travel less than six miles in search of new homes, but movements of up to 150 miles have been documented.
  • Colonies usually consist of six to eight animals, including an adult pair and the kits from the last two litters.
  • Beavers typically live in lodges built from branches, mud and other debris or in dens dug into the banks of streams or lakes. Both dams and lodges are packed solid with mud to make them weatherproof. All residences have at least two openings and sometimes more.

Self-Help

Habitat Modification & Exclusion

  • Beavers are not good climbers, so a 3-4 foot fence can be a permanent deterrent. It is not necessary to completely encircle the area to protect it because the beaver may only be approaching from the waterside of the property.
  • An electrified wire strung approximately 4 inches off the ground can also prevent beavers from entering an area.
  • Homemade or commercially available tree guards can prevent beaver damage to trees, especially where small (2- to 6-inch) trees need to be protected. Simple cylinders of galvanized, welded (2-inch x 2-inch) wire placed around the trunk and standing about 3 feet high can be used to cage trees.
  • Cylinders around larger trees may require staking and mulching within the cylinders to keep weeds from becoming a problem.
  • To prevent tree damage, frequently monitor the trees and put protective barriers in place on the first signs of damage. Larger or more desirable trees should be protected before damage occurs.
  • Destruction of the dam does not work since they will simply rebuild it.

Repellents

Scare off with loud noises, water hoses, or throw small stones.

Self-Help Trapping

This is not recommended. It is best to contact a licensed service or your municipality.

Problem Diagnosis

IS THERE A PROBLEM? HOMEOWNER SHOULD ACCEPT NORMAL, UNOBTRUSIVE BEHAVIOR

Refer to SELF-HELP if:

  • The beaver is confined but able to leave on its own.
  • Anyone is deliberately or inadvertently feeding it.
  • Property damage has occurred.

Refer to PROFESSIONAL ASSISTANCE if:

  • A beaver is posing an immediate threat to public safety.
  • The animal is injured.
  • If a young animal is orphaned.
  • A bite has occurred.
  • Homeowner is unable or unwilling to exercise self-help options.

Professional Assistance

  • Humane Wildlife Control (514-395-4555)
  • In the case of a bite: If a domestic pet has been bitten, bring the pet immediately to the vet. In off-hours, emergency cases can be brought to DMV, a 24-hour veterinary service. However, this clinic, though extremely thorough and knowledgeable, is also quite expensive. If a human has been bitten, bring them directly to a hospital.