Damage Prevention and Control Methods
Fencing can help reduce woodchuck damage. Woodchucks, however, are good climbers and can easily scale wire fences if precautions are not taken. Fences should be at least 3 feet (1 m) high and made of heavy poultry wire or 2-inch (5-cm) mesh woven wire. To prevent burrowing under the fence, bury the lower edge 10 to 12 inches (25 to 30 cm) in the ground or bend the lower edge at an L-shaped angle leading outward and bury it in the ground 1 to 2 inches (2.5 to 5 cm). Fences should extend 3 to 4 feet (0.9 to 1.2 m) above the ground.
Place an electric wire 4 to 5 inches (10 to 13 cm) off the ground and the same distance outside the fence. When connected to a UL-approved fence charger, the electric wire will prevent climbing and burrowing. Bending the top 15 inches (38 cm) of wire fence outward at a 45o angle will also prevent climbing over the fence.
Fencing is most useful in protecting home gardens and has the added advantage of keeping rabbits, dogs, cats, and other animals out of the garden area. In some instances, an electric wire alone, placed 4 to 5 inches (10 to 13 cm) above the ground, has deterred woodchucks from entering gardens. Vegetation in the vicinity of any electric fence should be removed regularly to prevent the system from shorting out.
Scarecrows and other effigies can provide temporary relief from woodchuck damage. Move them regularly and incorporate a high level of human activity in the susceptible area.
None are registered.
None are registered for woodchuck control.
- Gas cartridge (carbon monoxide).
The most common means of wood-chuck control is the use of commercial gas cartridges. They are specially designed cardboard cylinders filled with slow-burning chemicals. They are ignited and placed in burrow systems, and all entrances are sealed. As the gas cartridges burn, they produce carbon monoxide and other gases that are lethal to woodchucks. Gas cartridges are a General Use Pesticide and are available from local farm supply stores, certain USDA-APHIS-Wildlife Services state and district offices, and the USDA-APHIS-Wildlife Services Pocatello Supply Depot. Directions for their use are on the label and should be carefully read and closely followed (see information on gas cartridges in the Pesticides and Supplies and Materials sections).
Be careful when using gas cartridges. Do not use them in burrows located under wooden sheds, buildings, or near other combustible materials because of the potential fire hazard. Gas cartridges are ignited by lighting a fuse. They will not explode if properly prepared and used. Caution should be taken to avoid prolonged breathing of fumes.
Each burrow system should be treated in the following manner:
1. Locate the main burrow opening (identified by a mound of excavated soil) and all other secondary entrances associated with that burrow system.
2. With a spade, cut a clump of sod slightly larger than each opening. Place a piece of sod over each entrance except the main entrance. Leave a precut sod clump next to the main entrance for later use.
3. Prepare the gas cartridge for ignition and placement following the written instructions on the label.
4. Kneel at the main burrow opening, light the fuse, and when the cartidge ignites, place it (do not throw) as far down the hole as possible.
5. Immediately after positioning the ignited cartridge in the burrow, close the main opening or all openings, if necessary, by placing the pieces of precut sod, grass side down, over the opening. Placing the sod with the grass side down prevents smothering the lit cartridge. Make a tight seal by packing loose soil over the piece of sod. Look carefully for smoke leaking from the burrow system and cover or reseal any openings that leak.
6. Continue to observe the site for 4 to 5 minutes and watch nearby holes. Continue to reseal those from which smoke is escaping.
7. Repeat these steps until all burrow systems have been treated in problem areas.
Burrows can be treated with gas cartridges at any time. This method is most effective in the spring before the young emerge. On occasion, treated burrows will be reopened by another animal reoccupying the burrow system. If this occurs, retreatment may be necessary.
Aluminum Phosphide. Aluminum phosphide is a Restricted Use Pesticide and can be applied only by a certified pesticide applicator. Treatment of burrow systems is relatively easy. Place two to four tablets deep into the main burrow. Plug the burrow openings with crumpled newspapers and then pack the openings with loose soil. All burrows must be sealed tightly but avoid covering the tablets with soil. The treatment site should be inspected 24 to 48 hours later and opened burrows should be retreated.
Aluminum phosphide in the presence of moisture in the burrow produces hydrogen phosphide (phosphine) gas. Therefore, soil moisture and a tightly sealed burrow system are important. The tablets are presently approved for outdoor use on noncropland and orchards for burrowing rodents. Tablets should not be used within 15 feet (5 m) of any occupied building or structure or where gases could escape into areas occupied by other animals or humans. Storage of unused tablets is critical — they must be kept in their original container, in a cool, dry, locked, and ventilated room. They must be protected from moisture, open flames, and heat.
The legal application and use of aluminum phosphide for woodchuck control may vary from state to state. Check with your state pesticide registration board, USDA-APHIS-Wildlife Services representative, or extension agent when considering use of this material. Aluminum phosphide should always be applied as directed on the label.
Steel leghold and live traps. Traps may also be used to reduce woodchuck damage, especially in or near buildings. Both steel leghold and live traps are effective. Trapping should be used in areas where gas cartridges or aluminum phosphide may create a fire hazard or where fumes may enter areas to be protected. Woodchucks are strong animals and a No. 2 steel trap is needed to hold them. Before using steel traps, consult your state wildlife department or USDA-APHIS-Wildlife Servcies representative for trapping regulations. Steel traps should not be employed in areas where there is a possibility of capturing pets or livestock.
Live trapping can sometimes be difficult, but is effective. Live traps can be built at home, purchased from commercial sources (see Supplies and Materials), or borrowed. Bait traps with apple slices or vegetables such as carrots and lettuce, and change baits daily. Locate traps at main entrances or major travel lanes. Place guide logs on either side of the path between the burrow opening and the trap to help funnel the animal into the trap. Check all traps twice daily, morning and evening, so that captured animals may be quickly removed. A captured animal can be relocated to an area with suitable habitat where no additional damage can be caused. In the state of Michigan, no wildlife can be relocated without a specific permit from the Department of Natural Resources. The animal can also be euthanized by lethal injection (by a veterinarian or under veterinarian supervision), by shooting, or by carbon dioxide gas.
Conibear® traps. Conibear® traps are effective in some situations. A set in a travel way, such as between a wood pile and barn, can be very effective. Sets can also be made at the main entrance of the burrow system. Logs, sticks, stones, and boards should be used to block travel ways around the set and/or to lead the animal into the set. No bait is necessary for Conibear® sets. Conibear® 110s, 160s, and 220s are best suited for woodchuck control. Conibears® are well suited for use near or under structures in which fumigants and shooting present a hazard. Conibear® 110s will handle young, small animals, while 160s and 220s will also handle larger adults.
Conibear® traps kill the animal quickly and care should be taken to avoid trapping domestic animals such as cats and dogs. Some state or local laws prohibit the use of Conibear® traps except in water. Consult your state wildlife department or USDA-APHIS-Wildlife Services office for regulations.
In many states, woodchucks are considered game animals. Therefore, if shooting is permitted, a valid state hunting license may be required. In some states there is no closed season, nor is there usually any limit on the number of woodchucks that can be taken by hunters. If shooting can be accomplished safely, landowners and/or hunters can reduce or maintain a low population of woodchucks where necessary. Landowners and hunters should agree on hunting arrangements prior to initiating any shooting activities. Another alternative would be to have a professional USDA-APHIS-Wildlife Services representative do the job. He or she will be familiar with legalities and techniques. Contracting with a Wildlife Services professional would be especially valuable when and where large numbers of woodchucks are causing serious economic losses. Shooting can be used as a follow-up to other, more substantial control activities.
Rifles with telescopic sights are commonly used in the sport shooting of woodchucks. A variety of calibers can be used, but .22-caliber center fire rifles are most popular. Occasionally, shotguns are used to eliminate wood-chucks that are causing damage. The objective is to remove the animal as humanely as possible without wounding it. Shotgun gauge, range, and shot size should be considered when using this method. Use a 12-gauge with No. 4 to No. 6 shot. The range should be within 25 yards (23 m).
Carefully assess the area behind and around the target for safety. Pellets can ricochet, causing injury or serious damage in background areas. Use of a rifle or shotgun should be conducted only if good shooting conditions exist.
Damage Prevention and Control Methods
Buried welded or woven wire fences.
Single-strand electric fences.
Scarecrows and other effigies.
None are registered.
None are registered.
No. 2 leghold traps.