Damage Prevention and Control Methods
Fencing. Exclusion is most often accomplished by the construction of fences and gates around the area to be protected. Woven wire or poultry netting should exclude all hares from the area to be protected. To be effective, use wire mesh of less than 1 1/2 inches (3.8 cm), 30 to 36 inches (76 to 91 cm) high, with at least the bottom 6 inches (15 cm) buried below ground level. Regular poultry netting made of 20-gauge wire can provide protection for 5 to 7 years or more. Although the initial cost of fences appears high—about $1,000 per mile ($625/km)—they are economically feasible for protecting high-value crops and provide year-round protection on farms with a history of jackrabbit problems. Remember to spread the initial cost over the expected life of the fence when com-paring fencing with other methods. Exclusion by fencing is desirable for small areas of high-value crops such as gardens, but is usually impractical and too expensive for larger acreages of farmland.
Electric fencing has been found to exclude jackrabbits. Six strands spaced 3 inches (7.6 cm) apart alternating hot and ground wires should provide a deterrent to most hares. Modern energizers and high-tensile wire will minimize cost and maximize effectiveness.
Tree Trunk Guards. The use of individual protectors to guard the trunks of young trees or vines may also be considered a form of exclusion. Among the best of these are cylinders made from woven wire netting. Twelve- to 18-inch-wide (30.5-to 45.7-cm) strips of 1-inch (2.5-cm) mesh poultry netting can be formed into cylinders around trees. Cylinders should be anchored with lath or steel rods and braced away from the trunk to prevent rabbits from pressing them against the trees and gnawing through them.
Types of tree protectors commercially available include aluminum, nylon mesh wrapping, and treated jute cardboard. Aluminum foil, or even ordinary sacking, has been wrapped and tied around trees with effective results.
Wrapping the bases of haystacks with 3-foot-high (0.9-m) poultry netting provides excellent protection.
Habitat Manipulation. In areas where jackrabbit or hare damage is likely to occur, highly preferred crops such as alfalfa, young cotton plants, lettuce, and young grape vines are usually most damaged. Crops with large mature plants, such as corn, usually are not damaged once they grow beyond the seedling stage. Where possible, avoid planting vulnerable crops near historically high hare populations.
Overuse of range forage can sometimes lead to high jackrabbit numbers. Jackrabbits are least abundant where grass grows best within their range. Like many rodents, they prefer open country with high visibility to areas where the grass prevents them from seeing far. Thus, control programs accompanied by changes in grazing practices that encourage more vegetative growth may be necessary for longterm relief.
Guard Dogs. Dogs can be chained along boundaries of crop fields or near gardens to deter jackrabbits.
Since state pesticide registrations vary, check with your local Cooperative Extension or USDA-APHIS-Wildlife Services office for information on repellents legal in your area.
Various chemical repellents are offered as a means of reducing or preventing hare damage to trees, vines, or farm and garden crops. Repellents make protected plants distasteful to jackrabbits. A satisfactory repellent must also be noninjurious to plants.
Currently available commercial repellents include ammonium soaps, capsaicin, dried blood, napthalene, thiram, tobacco dust, and ziram. Repellents are applied during either the winter dormant season or summer growing season. Recommendations vary accordingly.
Be sure to use repellents according to the manufacturer’s guidelines and follow label recommendations.
Powders. Any repellent applications that involve the use of powders should be dusted on garden crops early in the morning when plants are covered with dew, or immediately after a rain. Do not touch plants with equipment or clothing because moist plants, especially beans, are susceptible to disease. When a duster is not available and only a few plants are involved, use a bag made of cheesecloth to sift repellent dust onto plant foliage. Repeated applications may be necessary after rains have washed the powder from the foliage and as new plant growth takes place.
Sprays. Thoroughly cover the upper surfaces of the leaves with spray repellent. If a sprayer is unavailable and only a small number of plants are involved, a whisk broom or brush can be used to apply the repellent to the plant foliage. The repellents will adhere to the foliage for a longer period if a latex-type adhesive is used. Reapply liquid repellents after a heavy rain and at 10-day intervals to make certain new plant growth is protected.
Some repellents are not registered for application to leaves, stems, or fruits of plants to be harvested for human use. A list of registered commercial repellents can be found in Supplies and Materials. Many of these may be purchased at a reasonable cost from suppliers handling seed, insecticides, hardware, and farm equipment.
Commercial repellents containing thiram are effective and can be applied safely to trees and shrubs. Treat all stems and low branches to a point higher than rabbits can reach while standing on top of the estimated snow cover. One application made during a warm, dry day in late fall should suffice for the entire dormant season. For further information on repellents and their availability, see Supplies and Materials.
Since state pesticide registrations vary, check with your local Cooperative Extension or USDA-APHIS-Wildlife Services office for information on toxicants legal in your area. Be sure to read the entire label. Use strictly in accordance with precautionary statements and directions. State and federal regulations also apply.
Anticoagulants. In areas where they are legal, anticoagulant baits may be used to control jackrabbits. Varying degrees of success have been reported with diphacinone, warfarin, brodi-facoum, and bromadiolone. Anticoagulants control jackrabbits and hares by reducing the clotting ability of the blood and by causing damage to the capillary blood vessels. Death is caused only if the treated bait is consumed in sufficient quantities for several days. A single feeding on anti-coagulant baits will not control jackrabbits. Brodifacoum and bromadiolone may be exceptions, but they are not yet registered for use on jack-rabbits. Bait must be eaten at several feedings on 5 or more successive days with no periods longer than 48 hours between feedings.
When baiting with anticoagulants, use covered self-dispensing feeders or nursery flats to facilitate bait consumption and prevent spillage. Secure feeding stations so that they cannot be turned over. Place 1 to 5 pounds (0.5 to 2.5 kg) of bait in a covered self-dispensing feeder or nursery flat in runways, resting, or feeding areas that are frequented by jackrabbits. Inspect bait stations daily and add bait as needed. Acceptance may not occur until rabbits become accustomed to the feeder stations or nursery flats, which may take several days. When bait in the feeder is entirely consumed overnight, increase the amount. It may be necessary to move feeders to different locations to achieve bait acceptance. Bait should be available until all feeding ceases, which may take from 1 to 4 weeks. Replace moldy or old bait with fresh bait. Pick up and dispose of baits upon completion of control programs. Dispose of poisoned rabbit carcasses by deep burying or burning.
Non-Anticoagulants. Zinc phosphide is registered for use on black-tailed jackrabbits in some states. Baits should be applied as per label recommendations .
No fumigants are registered for jackrabbits.
Trapping with box-type traps is not effective because jackrabbits are reluctant to enter a trap or dark enclosure. Snowshoe hares are susceptible to box-type traps.
Body-gripping and leghold traps can be placed in rabbit runways. Trapping in runways may result in unacceptable nontarget catches. Check for tracks in snow or dirt surfaces to be sure only target animals are present. Placement of sticks 1 foot (0.3 m) above the trap will encourage deer and other large animals to step over the trap while allowing access to jackrabbits or other hares. Be sure to check with local wildlife officials on the legality of trapping hares and jackrabbits.
Where safe and legal to do so, shooting jackrabbits may suppress or eliminate damage. Effective control may be achieved using a spotlight and a shooter in the open bed of a pickup truck. Driving around borders of crop fields or within damaged range areas and carefully shooting jackrabbits can remove a high percentage of the population. Some states require permits to shoot from vehicles or to use spotlights.
In some states sport hunting of jack-rabbits can be encouraged and may keep populations below problem levels.
Predators. Natural enemies of jackrabbits include hawks, owls, eagles, coyotes, bobcats, foxes, and weasels. Control of these predators should occur only after taking into account their beneficial effect on the reduction of jackrabbit populations.
Summary of Damage Prevention and Control Methods
Fencing. Tree trunk guards.
Manipulation of habitat. Planting of less desirable crops.
Ammonium soaps, capsaicin, naphthalene, thiram, tobacco dust, ziram.
Anticoagulants (where registered).
None are registered.
Body-gripping and leghold traps. Box traps.
Spotlighting and day shooting are effective where legal.