Overview
The beaver is North America’s largest rodent. Adult beavers normally weigh 40 to 50 pounds, but exceptionally large animals may weigh up to 80 pounds. They range in length from 35 to 50 inches, including the tail, which normally is about 10 inches long. Beavers today are found throughout all of the North American continent. Here in Virginia, biologists believe beavers are present in every county.
Beavers are important in that they create new habitats that benefit a variety of other animals. Their dams slow the flow of moving waters and allow other wildlife and plant species to colonize this modified ecosystem. Ducks and other waterfowl, as well as many reptiles, amphibians, and aquatic insects, are attracted to beaver ponds. However, the impaired flow and removal by beavers of the woody vegetation along the shoreline can raise the water’s temperature and allow more sediment to collect behind the dam. Lower dissolved oxygen levels and higher water temperatures may favor some organisms, but at the expense of others (e.g., trout and aquatic insects dependent upon cool, flowing waters).
Physical damage caused by beavers in the Southeast is estimated in the millions of dollars annually. Examples of this damage include timber and agricultural crop loss, damage to roads, septic systems and other property by flooding, and destruction of ornamental plants used in landscaping.
CONTROL TECHNIQUES:
To reduce the potential for damage to personal property, precautions should be taken before a beaver develops an interest in your property. As with most wildlife damage problems, no single technique exists that will provide absolute protection from beaver depredations. However, certain measures when initiated in a timely fashion, maintained properly, and applied with an understanding of the habits or behaviors of beavers can reduce the likelihood of significant damage. People residing within the beaver’s range (primarily owners of shoreline property) should recognize that beavers are clever and persistent animals and they may be able to circumvent some of the control techniques mentioned below. Therefore, anyone affected by beavers must be willing to implement a comprehensive management strategy involving multiple techniques.
TOLERANCE:
Knowing that beavers fulfill an important role in creating wetlands and providing new habitat for a variety of wildlife, an easy approach to dealing with beavers is simply to learn to live with them. Beavers are intriguing animals and being able to see how a beaver lives and to observe the engineering skills at work can be fun and educational. If a beaver has moved onto your property and is in a location that will not cause damage to driveways, septic systems, or landscaping, you may choose to leave the beaver alone. On small ponds and streams, a colony of beavers usually will leave the area after 4 to 7 years, or once the food supply they are dependent upon has been depleted. However, other wildlife species attracted to the pond the beavers abandoned will remain long after the beavers have left.
PREVENTIVE MEASURES:
Realistically, it is difficult to keep beavers away from your property once they take an interest in it. Techniques such as cutting down scrubby trees and other vegetation along the water’s edge and into the adjoining upland have been suggested as means to eliminate potential food sources and construction materials that beaver would use. Theoretically, this should cause them to overlook your property for other areas with more suitable resources. However, this has not been shown to be a feasible method of keeping beavers off your land and likely would have only a minimal impact on beaver.
REPELLENTS:
There is only one product registered by the US Environmental Protection Agency for use as a repellent on beavers. The active ingredient in this repellent is denatonium saccharide, and the formulation is marketed under the trade name Ro-pel®. Ro-pel is a bitter-tasting liquid that can be painted or sprayed on trees, shrubs, and ornamental landscaping to deter chewing. Ro-pel would be most effective when used at the first indication of beaver presence or in areas where beavers are most actively feeding. However, as is true with many other repellents, frequent reapplication may be required to maintain best results.
NON-LETHAL CONTROLS:
Non-lethal controls used to deter beavers can be expensive and require substantial investment of time by a landowner to put them into use. Examples include the use of fencing and water leveling devices.
Fencing
- Heavy gauge woven wire fence (2 inch x 2 inch mesh size) can be wrapped around the base of a tree and connected to itself using strong metal fasteners to create a tree guard that a beaver cannot pull apart.
- Never attach a guard directly to a tree with nails or staples.
- The tree guard should be wide enough to allow for normal tree growth (leave 1-2 inches of space all the way around) and at least 3 feet tall to prevent the beaver from reaching up and gnawing on the tree above the fence.
- Each guard should be staked securely to the ground to prevent the beaver from pushing under or lifting it (remember: put your support stakes inside the guard or the beaver will chew them off!).
- In areas where substantial snow cover may accumulate, tree guards should be taller to prevent beavers from standing on packed snow and reaching over the top of the guard.
- Temporary or permanent, single strand, high-tensile electric wire can be staked on short posts about 3-4 inches above the soil surface, and attached to a reliable charger (powered either by a direct 110-volt supply or a rechargeable battery pack).
- This “fence” should be constructed along the entire shoreline just above the slope where beavers would haul out of the water or across the paths beavers might use.
- The intent of this approach is to use the electric wire to deter beavers from coming out of the water and gaining access to areas where valuable trees, landscape plantings, or other vegetation likely would be cut and removed. The electric wire delivers a mild shock to the beaver in the nose/head region and encourages the animal to move to another location.
- Such fencing requires periodic maintenance to remove limbs that may have fallen across the wire and grass or weeds growing up beneath and contacting the wire, both of which will ground or short the electric circuit.
- Other types of prefabricated electric and non-electric fences are available commercially. Some of the simplest prefab electric setups are made with support posts already attached. A landowner simply unrolls the fence, pushes the stakes in the ground, and has a fast, easy set-up ready to charge.
- Fences can be used in two ways: (a) as a horizontal barrier between the shoreline and the land to be protected from beavers, and (b) as an enclosure to protect an area or group of plantings from the beaver.
- Any electric fence must be used with caution, especially around young children and pets. In fact, many municipalities have adopted ordinances prohibiting the use of electric fencing. Landowners must check with local authorities to determine if it is legal to operate an electric fence in their area before installing and activating any such device.
Water Leveling Devices
Water leveling devices are used to manipulate the level of water behind a beaver dam or plugged road culvert without a need to remove the dam or destroy the beavers. These devices disperse the flow of water in a way that beavers do not detect a leak nor are they alerted to the strong sound of running water, which would trigger them to find and plug a suspected breach in the dam. Water leveling devices can be made from a variety of materials, including wood, logs, plastic and metal pipes, and mesh covered boxes or troughs. Some of these devices can be a bit complicated to build and most will require the services of a hydraulic engineer to properly assess or gauge the volume of flow in the water source and to determine how many leveling units would be needed to adequately handle that volume. Also, because alteration of a beaver dam may affect the integrity of the wetland system upstream from it, an alteration permit may be required under local, state, and/or federal wetland regulations; landowners must check with permitting authorities before any alteration work begins and construction of such devices is contemplated.
Some examples of water-leveling devices include the following:
- The Clemson Beaver Pond Leveler-this device consists of a variable length, solid, 8-inch diameter, polyvinylchloride (PVC) culvert pipe and elbow riser as a discharge unit coupled to an intake device made from a 10-foot section of 8-inch diameter, perforated PVC pipe surrounded by a cylinder of galvanized welded wire. The height of the elbow riser will determine the elevation of the water behind the dam.
- The 3-Log Drain-this device is constructed by lashing 3 full-length logs together and fastening sections of roofing tin to the bottom of the lashed logs. By inserting the device into a notch cut in the dam and parallel to the direction of flow, this drain will be incorporated into the structure of the dam as the beavers repair the cut you made in the dam. However, water will continue to flow between the logs that comprise this device and allow water to be maintained at a desired elevation.
- A variety of other beaver flow pipes-there are many designs for other pipes that can be inserted through a beaver dam or road culvert to regulate the flow of water out of the impoundment. Modifications to the upstream end of these devices, ranging from simple holes cut into the pipe or the addition of strainer baskets, diffuser caps, or “T” shaped attachments, are used to spread the intake of water over a larger area and help avoid a concentrated flow of water into the device. Similarly, various attachments have been affixed to the outflow end to help silence the flow of water coming out (to avoid raising suspicion in the beaver that a leak may have occurred) and to establish the desired elevation of water within the impoundment.
All of these devices are designed to be incorporated into the dam structure. Pipes should extend a considerable distance back into the pond and away from the dam (a minimum of 20 feet) to reduce the likelihood of detection by beavers and thus prevent them from plugging up the intake pipe. A key factor in assuring success with a water leveling device is to not drop the elevation of the water in the impoundment below a level that will expose the opening to the den or lodge. If that happens, beavers often will move either upstream or downstream from the existing dam and construct another structure that will reestablish water cover over the lodge opening. Therefore, correct installation of these devices requires time and some engineering knowledge. Water leveling devices often can be expensive; costs range from a few hundred to several thousand dollars, depending on the price of the construction materials and the number of devices needed to properly handle the volume of flow. However, when properly sized and placed, water control devices provide an opportunity for beaver and landowners to coexist without the serious threat of flooding.
LETHAL CONTROLS:
If all attempts to deter beaver from your land have failed, then removal of the problem animals may be necessary. Where damage to timber, crops, ornamental or landscape plants, septic systems, or roads has occurred, the owner or lessee of the property may receive authorization to remove a colony of beavers, but only after the damage has been reported to and verified by the local conservation police officer (CPO) (þ29.1-518 of the Code of Virginia, Wildlife and Fish Laws). The CPO will issue a permit that clearly states any limitations on the taking of beaver (e.g., length of time permit is valid, authorized methods of kill, disposition of any carcasses) and requires that a report is sent to VDGIF that summarizes the outcome of beaver removal efforts.
Two methods commonly used to remove beaver are trapping and shooting the problem animals. Other lethal methods of take, such as the use of poisons, are not allowed in Virginia. There currently are no toxicant or fumigant products registered by the US Environmental Protection Agency for use on beavers.
Trapping
Trapping can be an efficient and cost effective means to manage beaver populations within watersheds. Although trapping will not prevent beavers from recolonizing suitable habitat in the future, it does provide affected individuals and communities with a methodology to keep beaver numbers in balance with society’s desires and tolerances.
Even though landowners may be allowed to use traps to capture beaver, many individuals today are not familiar with the technology nor do they possess the equipment and field skills necessary to be successful. Thus, trapping may best be left to professionals. Your local warden may be able to recommend a licensed trapper who would be willing to help you. Alternatively, representatives from the Virginia Trappers Association (VTA) might be willing to assist landowners wanting to have beavers removed from a property (for those with internet access, here is the homepage for the VTA).
Two basic types of traps are available for taking beaver: live traps and kill traps. Live traps are designed to capture the animal alive and allow the trapper some options in the disposition of the captured animal whereas kill traps, as the name implies, are designed to put the animal to death as humanely as possible. Bailey and Hancock “suitcase-type” traps are examples of live traps suitable for capturing beaver. However, by state regulation, any beaver captured alive by a homeowner may not be removed from that property and transported and released elsewhere. This restriction is intended primarily to prevent the potential transfer of a beaver problem from one area to another.
The Conibear®, a type of body-gripping trap, is an example of a commonly used and authorized kill trap for beaver. Steel leghold traps also may be used to capture beaver. Snares with an opening of less than 12 inches in diameter and set with the top of the loop not more than 12 inches above the ground may be used, but only on private lands and only with written permission of the landowner. In situations where body-gripping or leghold traps or snares are used, trappers must possess the required license or permit and all traps used must bear a metal tag that displays the trapper’s name and address. Specific details on allowable trap sets and sizes, dates of trapping seasons, and allowable bag limits are available in a summary of hunting and trapping regulations published annually by the VDGIF. Similarly, your local CPO can provide answers to any questions you may have about state trapping regulations. For additional details on specific trap sets and designs, readers are encouraged to review Miller and Yarrow (1994), cited at the end of this publication.
Shooting
Although allowed by state law, shooting raises a number of practical and safety concerns. Many cities and towns have local ordinances that prohibit the discharge of firearms within their municipal boundaries. Before considering shooting as an option, you must first determine whether a firearm can be used in your area. Where shooting is allowed, special care should be taken when firing at or near water bodies. Rifle shots aimed toward water are subject to ricochet and slugs glancing off water can travel substantial distances; thus, care must be taken prior to pulling the trigger to verify that a safety zone exists well beyond the target area. To reduce the potential for ricochet, consider using a shotgun with heavy waterfowl loads or buckshot instead of a rifle. Also, whenever possible, beavers should be shot while they are on land. It is advisable that advanced notification be given to your local CPO and/or police department if you intend to implement a shooting effort outside the normal hunting season. By so doing, you will save them time and effort that might needlessly be wasted in investigating and responding to calls of firearms being discharged in your area.
Legal Considerations
In Virginia there are many laws that pertain to beaver. The Virginia Department of Game and Inland Fisheries recognize that beavers can have adverse effects to property, therefore they have added additional legislation that allows for the taking of beaver out of season despite its fur-bearer classification.
Virginia fur-bearing laws prevent the trapping beaver out of season on your property � 29.1-530, although section 29.1-518 of the Virginia Code allows for a landowner to shoot a beaver if it is damaging crops or lands assuming the discharge of a firearm is legal in the county or city of residence. Due to highly populated areas not allowing the discharge of firearms the Virginia Department of Game and Inland Fisheries has deemed it legal to trap beaver out of season (4VAC15-60-20) in the counties and cities of Arlington, Chesterfield, Fairfax, Henrico, James City, Loudoun, Prince William, Spotsylvania, Stafford, Roanoke and York. A landowner should use lethal alternatives only after all non-lethal controls have been exhausted.
In Virginia it is illegal to
- destroy or molest the dens or young of beaver. § 29.1-521.
- set a trap where it would be likely to injure persons, dogs, stock or fowl. § 29.1-521.
- not visit all traps once each day and remove all animals caught. § 29.1-521.
- trap beaver out of season on your property � 29.1-530 but you can shoot beaver year round. § 29.1-517. There is a special exception that allows residents in the counties of Arlington, Chesterfield, Fairfax, Henrico, James City, Loudoun, Prince William, Spotsylvania, Stafford, Roanoke and York to trapping beaver out of season.
- transport or release a beaver anywhere other than the property it was caught on. 4VAC15-30-50
- poison any animal including beaver. 4VAC15-40-50
In Virginia it is legal to
- A landowner may shoot beaver on their property during the closed season.§ 29.1-517
- When beaver are damaging crops or land the landowner can have the animal killed.§ 29.1-518
Additional Reading
Virginia