Beavers

Beavers

Busy Little Beavers in Reston

Reston Association, with the support of Reston’s homeowners, is committed to conserving the widest diversity of natural resources and promoting a peaceful coexistence between all its inhabitants. Beavers are one of Reston’s most conspicuous residents. While they create wetland habitat for many other species of wildlife to enjoy, at times their creative engineering may cause conflicts with other land users.

Characteristics

The beaver (Castor canadensis) is the largest rodent in our area of North America. Adults may be 3 to 4 feet long, including their tail, and weigh between 30 and 60 pounds. Beavers are highly adapted for aquatic living. They possess a dense fur coat for insulation, powerful, webbed hind feet for swimming and dexterous front fee for digging and manipulating materials.

Habitat

Most mammals leave little sign of their presence, but the opposite is true for beavers. They are best known for their ability to create a habitat to suit their needs. The most recognized structure is the beaver dam. Its purpose is to create a pond to provide a means to transportation and to protect the underwater entrance to their lodge.

To build a dam, beavers cut small trees or use branches from larger trees. The cuttings are then dragged or floated to the dam site, where they are anchored to the bottom and to each other with stones and mud. The dam is added to until the size of the pond meets the needs of the beaver. The dams are not waterproof and require constant attention. High storm waters will frequently carry away large portions of a dam, but the beavers are quick to repair the damage. In addition to the pond, a series of canals may be constructed to allow safe travel to distant sources of food or to connect ponds together.

In Fairfax County, most lodges are burrowed into the soft banks of creeks or rivers. In the absence of these areas, a lodge of sticks and mud may be built. Some beavers seem to prefer a bank den, with the protection of a boat dock. In all cases, the entrance is below the water surface. The living quarters may shelter as many as 8 to 10 family members, which typically includes an adult pair, several yearlings and kits. A litter usually consists of 4 kits born in mid-spring. Once beavers mature at the age of 2 or 3, they leave and establish their own territory in the same or neighboring watershed.

The diet of the beaver changes with the seasons. In the summer, beavers feed mainly on leafy green vegetation, especially cattails and other aquatic plants. As winter approaches, twigs and bark are the food of choice. Many cuttings are stored under the water for use during the winter months. Most trees chosen for food and building are less than 4 inches in diameter, but beaver will cut many larger trees. At times, beaver will eat almost any tree species, but tend to prefer aspen, willow and dogwood.

The Impact of Beavers

The flooding of stream valley woodlands leads to the death of trees and the creation of wetlands. These areas provide habitat for a large variety of plants and animals. Wood ducks, great blue herons and kingfishers are among the birds that enjoy these areas. Wetlands also aid in impounding flood waters and trapping sediments and nutrients.

The beaver was eradicated from the territory of Virginia very soon after European colonization. However, beavers were reintroduced to Virginia early in this century. Now the beaver is flourishing in its former range. With the absence of natural predators and the low amount of trapping for fur, the beaver has met little resistance to reclaiming its place in now more urbanized areas.

Beavers have no awareness of human property and conflicts may occur. The flooding of pathways and damage to trees and docks are only a few of the problems which may occur.

Planners, landowners and policymakers should consider ecological benefits as well as property damage when developing beaver control policies. That's according to the results of a study conducted by the University of Georgia's Savannah River Ecology Laboratory. Although often considered pests by landowners, beavers are a "keystone" species–one whose presence creates a favorable environment for other wildlife, according to researcher Krista Lee Clements. Clements found that beavers contribute significantly to the diversity of bird species in streamside areas by creating new wetlands, which enhances nesting and feeding opportunities.

Wildlife is an important part of our community. All residents benefit from common land, while at the same time assuming a shared responsibility for wildlife’s well being. RA recognizes beavers as part of Reston’s wealth, because of their contributions to the diversity and quality of natural habitat. When conflicts arise as a result of beavers’ activities, the significance of the impact on all involved will determine the actions to be followed.

When a Conflict Arises

It is the responsibility of the property owner to take reasonable steps to exclude problem wildlife from their property. In the case of the beaver, steps to make trees or shrubs unattractive or unavailable may be necessary. In addition, steps should be taken to protect underwater structures as well. Private property owners should consider the following:

  • Repellents are usually not effective and should not be relied on. Ropel is one repellent that can be used with limited success
  • Sturdy fencing is the only foolproof means of exclusion. Individual trees are best wrapped with hardware cloth forming a cylinder, 6 inches away from the turn. Property is best fenced with welded wire fencing. Both of these materials are available at local hardware stores
  • Metal sheeting can be applied to underwater parts of bulkheads to prevent beaver damage to the understructure of boat docks.

In the event that exclusion is ineffective or impractical, harassment techniques may be implemented. For beaver, these measures may include repeated opening of the dam or lodge. This may force the animals to seek new territory. However, it is against RA guidelines for private citizens to tamper with dams or lodges on common grounds.

If exclusion or harassment techniques prove to be ineffective, then as a last resort, trapping may be employed to remove the animals. State regulations control the final disposition of trapped beavers and opportunities for relocation may be limited.

Reston Association will provide information, advice, consultation and referrals if needed. However, RA cannot provide fencing for each individual homeowner’s property.

For help in resolving conflicts with beavers or other wildlife, please contact RA at 703-435-6547.

This fact sheet and policy statement is in response to past conflicts with beavers in Reston. While this is not a change in policy, it reiterates that any action to be taken regarding a conflict with wildlife will be determined on a case by case basis.

Nature Resources