Town of Richmond Hill Beaver Management Policy Summary

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1 Town of Richmond Hill Beaver Management Policy Summary Above Left: Tree damage from beaver. Above Right: Beaver dam in stream - notice the water level above and below the dam! Below: Beaver swimming. Town of Richmond Hill, Parks, Recreation and Culture Natural Heritage Section April 2003 Summary updated December 2008

2 Beavers - General Information Hunted to the brink of extinction from the 1700s until the decline of the fur trade in the 1970s, the North American beaver (Castor canadensis) has made a remarkable recovery. Beavers have recolonized much of their native territory and once again lodges and dams are becoming a familiar sight in Southern Ontario. The presence of beavers within urban areas has given rise to both interest and concern, and therefore, the Town of Richmond Hill has developed a policy to guide management decisions for human-wildlife conflicts involving beavers. Beavers are large rodents that can grow to be 1.2 m in length and weigh up to 30 kg. They are characterized by features adapted to their aquatic environment such as: webbed feet, dense underfur, valved ears and nose, and lips which close behind their large front teeth. Beavers mate for life and live in family units called colonies. A single beaver lodge could be occupied by as many as nine beavers. Each year a mated pair of adult beavers will produce two to five young, called kits. Kits are born in the spring and generally do not move from the lodge for a period of one month. At about two years of age a beaver reaches sexual maturity and will migrate along streams or over land until it locates a mate and suitable habitat to start a family. Beavers disperse from just a few kilometres up to 250 kilometres away from their birth lodge. Beavers are nocturnal creatures that do not hibernate. They are most active during the fall, working to store enough food (piled outside the lodge) to sustain them throughout the winter. Their diets include the bark of trees, water plants (pond lilies and cattail roots), shrubs, saplings, grasses, herbs, leaves and fruits. Their eating habits change with the seasons according to what food sources are plentiful at that time of year. They favour poplar, willow, cottonwood, aspen, beech, alder, hickory, and birch trees. A family of five or six beavers may require in excess of one half hectare of dense poplar trees for its winter food supply. Beavers construct living areas, called lodges, in lakes or rivers. A lodge consists of a single room with a floor above the water surface and an underwater tunnel for access. Beaver dams expand the size of the pool around the lodge so the water is deep enough to remain unfrozen on the bottom all winter which is important so the beavers can still enter and exit the lodge. The pool created from a beaver dam also brings beavers closer to their food source without having to move far out of the water. Beavers are excellent swimmers but are slow and awkward on land, making them more vulnerable to predators. The construction activity of beavers can be beneficial, but it can also cause problems in urban areas. Beaver dams can create important wetland habitat for waterfowl and other wildlife, regulate high flow conditions during storm events, and reduce downstream bank erosion. In urban areas, beavers offer recreational and educational opportunities. Beaver activity in urban areas, however, also has the potential to cause serious damage to human structures and create hazardous situations. Damming activities may weaken engineered structures, and flood roads, trails, or basements. Girdled, cut or felled trees may topple other trees or 2

3 utility poles, or cause precarious overhangs that could fall onto public pathways and roadways. In addition, residents may be troubled by aesthetic damage caused by the removal of trees from parklands and their property. Above: Flooded trail from beaver dam. Right: Hanging tree hazard which has been felled by beavers. The Town of Richmond Hill Beaver Management Policy Since human encroachment into beaver habitat has led to the increased presence of beavers in urban areas, the Town must address ongoing beaver activity proactively. The Town of Richmond Hill Beaver Management Policy (2003) was established to provide an economical, humane and effective means of responding to the presence of beavers on Town owned and managed lands. The policy aims to ensure that residents will have opportunities to benefit from the presence of these animals in the Town, while property damage and human health and safety risks are minimized. The Policy is built on the following Beaver Management Principles: a) The Town response to beaver-related issues should be efficient, fiscally responsible, ecologically sound and humane. b) Residents who report damage caused by beavers, or the presence of beavers in their neighbourhood, should be provided information regarding beavers and the options for their control. c) The Town s Beaver Management Policy will be consistent with the Ontario Fish and Wildlife Conservation Act, recommendations of the Ontario Ministry of Natural Resources and the policy of the Toronto and Region Conservation Authority. d) The Town will cooperate with other levels of government, agencies and organizations in order to best address beaver management issues. 3

4 Beavers on Private Property If residents have a beaver on their property the first thing they should do is evaluate whether or not the beaver is really causing a problem. If the beaver can be left to continue carrying out its daily activities uninhibited, residents may find that from a recreational and educational perspective there is much to gain from the presence of these animals. Children in particular find beaver lodges and dams fascinating. If you re lucky, you may even be able to catch a glimpse of one of the animals in action - dusk and dawn are the best times to stakeout the area. If the beaver is causing a nuisance that cannot be tolerated, management options are: dam destruction, trapping and killing, relocating or prevention and exclusion techniques. Dam destruction is ineffective - the beaver(s) will always build the dam back up immediately after it is destroyed. Relocation of beavers is regulated under the Ontario Fish and Wildlife Conservation Act and is generally not an acceptable option because relocation transports the problem elsewhere, transmits disease amongst beaver populations, and usually results in suffering and/or death of the beaver which has been relocated to unfamiliar territory. Trapping and killing beavers is not ideal as it is expensive and leaves habitable areas vacant for new beavers to colonize. The Town of Richmond Hill recommends that trapping be used only under extreme circumstances, when other preventative measures have been exhausted and the beaver s activities are threatening property or human safety. Trapping may only be undertaken by a trapper licensed by the Ontario Ministry of Natural Resources (OMNR). The OMNR maintains a list of all such licensed trappers and is available upon request. Prevention/exclusion measures are the recommended management options. They should be attempted as a means of controlling the problem before trapping is undertaken. If possible, prevention/exclusion measures should also be implemented at the site after trapping, in order to prevent that area from being recolonized by another beaver. Prevention and Exclusion Techniques Prevention/exclusion measures (sometimes called harassment techniques) are used to discourage beavers from occupying a particular area, to manage water levels at a site already inhabited by beavers, or to get a beaver to move to another location. They should be implemented in late summer when the beaver is first starting to stock for the winter and there is still time for it to move to another place before the water freezes. They should not be carried out in the fall or winter when the beaver is making preparations to survive the winter. 4

5 The following are some of the prevention and exclusion measures which can be undertaken to resolve beaver problems. a. Tree Protection - The easiest prevention/exclusion method involves protecting trees. If the beaver is unable to utilize the tree supply in a particular area it will be forced to move on to find another source of food and building material. A single shrub or tree can be protected from damage by encircling it with securely fastened wire mesh. Wire mesh tree guard to prevent beaver gnawing. b. Tubular Culvert Protectors - Tubular culvert protectors confuse beavers, preventing them from creating a dam near a culvert. A protector can be constructed from concrete reinforcement wire extending from the outside of a culvert and rounded closed at least 2.5 m from the end of the culvert. The tubular protector requires only periodic maintenance, but may need major repairs if damaged by ice in the winter. c. Water Level Control Pipe - The water level controller (or Beaver Baffler as it is sometimes called) prevents the beaver dam from functioning in the way that the animal wants it to, thus encouraging the beaver to move on in search of a better living location. A baffler is made of a piece of PVC pipe with a minimum length of 3.0 m and a diameter adequate to carry the appropriate flow for the watercourse. A wire cage is fixed around one end of the pipe which is placed upstream of the dam. The other end is inserted through the dam and conducts water entering at the caged end across the dam. This device is most suitable in situations where a small pond is desirable or acceptable. d. Trapezoidal Fence ( Beaver Deceiver ) - The trapezoidal fence prevents construction of the dam near a culvert due to its shape. The narrow side of the trapezoid is formed by the culvert itself, the sides extending outward from either side of the culvert into the watercourse at an angle of degrees. The final side of the trapezoid runs parallel to the culvert and connects the two sides extending outward from the culvert. The three sides of the beaver deceiver should be constructed of heavy gauge wire fencing supported by cedar posts (which the beavers will not chew) buried at least 30 cm into the ground to prevent beavers from tunnelling underneath. The fence should be at least 30 cm higher than the water level. River run stone can be placed around the bottom of the fence to improve aesthetics, stabilize the fence and ensure drainage. The downstream end of the culvert should be covered with wire mesh to prevent beavers from entering downstream. 5

6 Further References Canadian Wildlife Service Hinterland Who s Who: Beaver. City of Toronto DRAFT City of Toronto Beaver Management Policy. Government of Ontario Fish and Wildlife Conservation Act, S.O. 1997, Ch. 41, Amended Fish and Wildlife Conservation Act, 1997, found online: ONTARIO REGULATION 196/00, found online: Ontario Ministry of Natural Resources. Extension Notes: Options for Controlling Beaver on Private Lands. Queen s Printer: Toronto. Toronto and Region Conservation Authority Policy for the Management of Human/Wildlife Conflicts on Authority Managed Lands. 6