For managing coyote damage, a variety of control methods must be available since no single method is effective in every situation. Success usually involves an integrated approach, combining good husbandry practices with effective control methods for short periods of time.
Regardless of the means used to stop damage, the focus should be on damage prevention and control rather than elimination of coyotes. It is neither wise nor practical to kill all coyotes. It is important to try to prevent coyotes from killing calves or sheep for the first time. Once a coyote has killed livestock, it will probably continue to do so if given the opportunity.
Equally important is taking action as quickly as possible to stop coyotes from killing after they start.
Most coyotes readily cross over, under, or through conventional livestock fences. A coyote’s response to a fence is influenced by various factors, including the coyote’s experience and motivation for crossing the fence. Total exclusion of all coyotes by fencing, especially from large areas, is highly unlikely since some eventually learn to either dig deeper or climb higher to defeat a fence. Good fences, however, can be important in reducing predation, as well as increasing the effectiveness of other damage control methods (such as snares, traps, or guarding animals).
Recent developments in fencing equipment and design have made this technique an effective and economically practical method for protecting sheep from predation under some grazing conditions. Exclusion fencing may be impractical in western range sheep ranching operations.
Net-Wire Fencing. Net fences in good repair will deter many coyotes from entering a pasture. Horizontal spacing of the mesh should be less than 6 inches (15 cm), and vertical spacing less than 4 inches (10 cm). Digging under a fence can be discouraged by placing a barbed wire at ground level or using a buried wire apron (often an expensive option). The fence should be about 5 1/2 feet (1.6 m) high to discourage coyotes from jumping over it. Climbing can usually be prevented by adding a charged wire at the top of the fence or installing a wire overhang.
Barrier fences with wire overhangs and buried wire aprons were tested in Oregon and found effective in keeping coyotes out of sheep pastures (Fig. 3). The construction and materials for such fencing are usually expensive. Therefore, fences of this type are rarely used except around corrals, feedlots, or areas of temporary sheep confinement.
Electric Fencing. Electric fencing, used for years to manage livestock, has recently been revolutionized by the introduction of new energizers and new fence designs from Australia and New Zealand. The chargers, now also manufactured in the United States, have high output with low impedance, are resistant to grounding, present a minimal fire hazard, and are generally safe for livestock and humans. The fences are usually constructed of smooth, high-tensile wire stretched to a tension of 200 to 300 pounds (90 to 135 kg). The original design of electric fences for controlling predation consisted of multiple, alternately charged and grounded wires, with a charged trip wire installed just above ground level about 8 inches (20 cm) outside the main fence to discourage digging. Many recent designs have every wire charged.
The number of spacings between wires varies considerably. A fence of 13 strands gave complete protection to sheep from coyote predation in tests at the USDA’s US Sheep Experiment Station. Other designs of fewer wires were effective in some studies, ineffective in others.
The amount of labor and installation techniques required vary with each type of fencing. High-tensile wire fences require adequate bracing at corners and over long spans. Electric fencing is easiest to install on flat, even terrain. Labor to install a high-tensile electric fence may be 40% to 50% less than for a conventional livestock fence.
Labor to keep electric fencing functional can be significant. Tension of the wires must be maintained, excessive vegetation under the fence must be removed to prevent grounding, damage from livestock and wildlife must be repaired, and the charger must be checked regularly to ensure that it is operational.