Effectiveness of livestock guarding animals for reducing predation on livestock. (Predation Management).
Predation is a major problem faced by domestic sheep (Ovis aries) and goat (Capra hircus) producers in the western United States. Producers have been incorporating livestock guarding dogs (Canis familiaris), llamas (Lama glama), and donkeys (Equus asinus), which appear to be effective in reducing these mortalities. The increased use of guarding animals to mitigate predation on livestock may reduce animosity toward predators and result in more positive attitudes toward the conservation of carnivores.
Predation by coyotes (Canis latrans), domestic dogs (Canis familiaris), mountain lions (Felis concolor), black bears (Ursus americanus), foxes (primarily Vulpes vulpes), eagles (primarily Aquila chrysaetos) and bobcats (Felis rufus) has been a major problem faced by domestic sheep producers, especially in the western United States (National Agricultural Statistics Service 2000). Pearson (1986) reported that coyotes, the primary predator of sheep, killed an average of one to 2.5% of adult ewes and four to 9% of lambs annually in the 17 western states. Several methods, including the use of livestock guarding dogs, llamas, and donkeys, have been used to reduce these mortalities (Andelt 1996). This paper reviews several studies of the effectiveness of livestock guarding animals and speculates on the implications for conservation of carnivores.
Livestock guarding dogs
Livestock guarding dogs have been used in the United States since the early 1970s to protect sheep (Ovis aries) and goats (Capra hircus) from predators. Most guarding dogs are members of breeds that have been developed selectively in Europe and Asia to protect livestock from bears (Ursus spp.) and wolves (Canis lupus). The most common breeds used for guarding livestock in the United States are Great Pyrenees, Akbash, and Komondor, whereas Anatolian, Kuvasz, Maremma, and Shar Planinetz are less common (Green and Woodruff 1988; Andelt and Hopper 2000). Most guarding dogs weigh 34 to 45 kg and are at least 64 cm at the shoulders. Successful guarding dogs are trustworthy (will not harm sheep), attentive to sheep, and aggressive toward predators (Coppinger et al. 1983). These traits are "instinctive"; they develop in most dogs with proper handling and minor training (Andelt 1995).
Andelt (1985) reported that guarding dog pups cost an average of $240 in Kansas and Green et al. (1984) reported pups cost an average of $331 and $458 (depending on breed) in the western United States. Annual maintenance fees (food, veterinary care, and miscellaneous costs) averaged $235 to $250 (Green et al. 1984; Andelt 1985).
The National Agricultural Statistics Service (2000) reported that 28% of sheep producers in the United States and 23% of producers in Colorado used guarding dogs to protect sheep during 1999. Andelt and Hopper (2000) reported that the percentage of sheep with guarding dogs in fenced pastures and on open range in Colorado increased from 7% in 1986 to 65% in 1993. They also indicated that producers primarily with large numbers of sheep have incorporated guarding dogs.
Sheep producers in Colorado who did not use livestock guarding dogs lost 5.9 and 2.1 times greater proportions of lambs to predators than producers who had dogs in 1986 and 1993, respectively (Andelt and Hopper 2000). Mortality of ewes to predators and lamb mortality on open range decreased more from 1986 to 1993 for producers who obtained dogs between these years compared to producers who did not have dogs. Thirty-six producers in North Dakota reported guarding dogs reduced predation on sheep by 93% (Pfeifer and Goos 1982). Producers in Colorado indicated that guarding dogs greater than nine months of age saved more time in sheep management than the amount of time spent feeding and working with each dog (Andelt 1992). Overall, guarding dogs are a cost-effective means of reducing predation (Green et al. 1984; Andelt and Hopper 2000).
Disadvantages of guarding dogs include: some dogs not staying with or harassing sheep; some dogs, especially Komondors, being overly aggressive toward people (Green and Woodruff 1988; Andelt 1992); and the dogs can be subject to injury and premature death. Many of the disadvantages are relatively uncommon. Most producers surveyed feel strongly that the advantages of their dogs far outweigh the disadvantages.
Green and Woodruff (1988) reported that the rate of success in protecting livestock from predators did not vary among Great Pyrenees, Komondor, Akbash, Anatolians, Maremma, and hybrids, nor was the rate of success different among males and females or intact and neutered dogs. Dogs that were reared with livestock from at most two months old, however, had a significantly higher rate of success than dogs that were older than two months when placed with livestock. Andelt (1999) reported that ratings of the effectiveness of guarding dogs by producers using one breed of dog in Colorado did not differ among breeds, but producers that used multiple breeds rated Akbash more effective than Great Pyrenees and Komondors.
Llamas have been used to deter predation primarily by coyotes, red foxes (Vulpes vulpes), and dogs since the early 1980s. The National Agricultural Statistics Service (2000) reported that 13% of the sheep producers in the United States used llamas to protect sheep from predators during 1999. Llamas are naturally aggressive toward coyotes and dogs. Typical responses of llamas to coyotes and dogs are being alert, alarm calling, walking to or running toward the predator, chasing, kicking, or pawing the predator, herding the sheep, or positioning themselves between the sheep and predator.
Franklin and Powell (1993) surveyed 145 producers that used llamas, primarily in Montana, Wyoming, Colorado, California, and Oregon. Most producers used one gelded male with 250 to 300 sheep in 250 to 300 acre pastures. Nearly all llamas were not raised with sheep and were not trained to guard sheep. One llama was more effective than multiple llamas for deterring predation; the effectiveness of gelded males, intact males, and females was similar. Producers reported, however, more problems with intact (25% of 61 intact males) than gelded males (5% of 135 gelded males) attempting to breed with ewes. Sheep that were introduced to llamas in corrals initially sustained lower mortality than those introduced in pastures. The success of llamas was not related to age when the llama was introduced, age of llama (after one or two years old) when guarding, if lambs were present or absent when the llama was introduced, or between open and covered (forested, shrub lands, gullies, ravines, etc.) habitat.
Franklin and Powell (1993) reported that gelded male llamas cost $700 to $800, whereas intact males were about $100 less. Most producers reported that daily care for llamas was the same as for sheep and that no special feeds were provided. Average annual expense was $90 for feed (not including pasture) and veterinary costs were about $15.
Franklin and Powell (1993) reported that 21% of ewes and lambs were killed annually before acquiring a llama and 7% afterwards. Meadows and Knowlton (2000) reported that producers with llamas lost significantly fewer sheep (n = 42) to predators than producers without llamas (n = 128) during the first year of use, but sheep mortalities did not differ between producers with (n = 35) and without (n = 32) llamas during the second year in Utah.
The National Agricultural Statistics Service (2000) reported that 9% of sheep producers in the United States used donkeys (Equus asinus) to protect sheep from predators during 1999. Donkeys apparently have an inherent dislike for dogs and other canids. They will bray, bear their teeth, run and chase, and attempt to bite and kick an intruder (Green 1989).
Donkeys apparently are most effective in small open pastures or where sheep graze together. Green (1989) and Walton and Feild (1989) recommended using only one jenny or gelded jack per pasture because two or more donkeys often stay together instead of being with the sheep. Intact jacks generally are too aggressive around sheep. Donkeys generally should be allowed four to six weeks for bonding with sheep before they are used to deter predators. Donkeys should be removed during lambing because they might trample lambs or disrupt the ewe-lamb bond. Green (1990) recommended challenging a donkey with a dog to test its response to canids; donkeys that are not aggressive should not be used.
Walton and Feild (1989) reported that the average purchase price per donkey was $144. They also reported that average annual upkeep per donkey was $66.
Bonding sheep and goats to cattle
Bonding young sheep to cattle (Anderson et al. 1987; Hulet et al. 1987) and goats to sheep that have been bonded to cattle (Hulet et al. 1989) has reduced coyote predation. This technique has not been readily adopted by sheep producers, possibly because of the additional labor and expense involved with bonding sheep and goats to cattle.
Relative effectiveness of guarding animals
Benefits of using guarding animals include a decrease or elimination of predation, reduced labor to confine sheep at night, more efficient use of pastures for grazing, reduced reliance on other predator control techniques, and a greater peace of mind. A comparison of surveys where producers reported the average annual value of sheep saved per guarding animal suggests guarding dogs, compared to llamas, saved more sheep from predators (Table 1). Guarding dogs and llamas have been rated as more effective than donkeys for deterring predation. The above comparisons should be interpreted conservatively because guarding dogs, llamas, and donkeys were not surveyed in the same studies nor under the same sheep management conditions.
Advantages of donkeys and llamas over guarding dogs include: less prone to accidental death; longer-lived; do not require special feeds; stay in the same pasture as sheep; apparently do not need to be raised with sheep; more compatible with other depredation control techniques such as traps, snares, M-44s, and livestock protection collars; and donkeys are cheaper than guarding dogs. Guarding dogs apparently have some advantages over donkeys and llamas. Guarding dogs deter predators in fenced pastures and on open range, whereas llamas and donkeys appear most effective in fenced pastures smaller than 300 acres. Guarding dogs are effective in deterring bear and mountain lion predation (Green and Woodruff 1989; Andelt and Hopper 2000), whereas some donkeys (Green 1989) and possibly llamas are afraid of bears and mountain lions. Guarding dogs also appeared successful in protecting cattle from wolf predation (Coppinger et al. 1988), and were fairly effective in keeping wolves and black bears from carrion feeding sites in Minnesota (Coppinger et al. 1987).
Several methods, including livestock confinement, disposal of livestock carcasses, herders, fencing, frightening devices, trapping, snaring, sodium cyanide ejectors, "denning" (locating the dens of depredating coyotes and killing the pups and/or adults), aerial hunting, ground shooting, hunting with decoy dogs, livestock protection collars, and poison baits have been used to reduce predation on livestock (Andelt 1996). Poison baits were withdrawn from use in 1972 (Andelt 1996), and use of some methods such as trapping, snaring, sodium cyanide ejectors, gas cartridges for denning coyotes, and livestock protection collars have been restricted or eliminated by ballot initiatives in some states such as Arizona, California, Colorado, and Massachusetts (Manfredo et al. 1999). The public also has rated guarding animals as more acceptable than most other techniques for reducing predation (Arthur 1981; Reiter et al. 1999). Thus, guarding animals are one of the few remaining successful techniques, in some states, that livestock producers can use to mitigate predation.
Green and Woodruff (1989) and Green et al. (1993) reported that guarding dogs repelled black bears and grizzly bears (Ursus arctos) during most encounters, and Andelt and Hopper (2000) reported that producers with guarding dogs, compared to producers without guarding dogs, sustained fewer ewe and lamb mortalities to black bears. Thus, guarding dogs may offer some potential for reducing grizzly bear predation on livestock, which may result in conserving more bears,
Many of our carnivores are found on private lands and in areas where livestock are grazed on private and public lands. Producers need to have successful techniques for resolving predation on livestock. Without successful methods, predation on livestock will increase and animosity by livestock producers toward predators likely will also increase, which will result in fewer attempts to conserve carnivores. Without successful techniques, producers also may sell their land for other uses, such as subdivisions, which are less conducive to carnivore conservation. Thus, guarding dogs, llamas, and donkeys should be thought of as valuable additions to the toolbox of management practices that reduce predation on livestock. In addition, use of guarding animals may result in enhanced conservation of carnivores.
Table 1. Average annual value of sheep saved from predation by each livestock guarding animal and ratings of effectiveness of guarding animals as reported in various studies. Factor Guarding Llamas Donkeys dogs $3,836 (a) Value of sheep saved $2,506 (c) $1,253(b) $3,733 (c) Ratings of effectiveness very effective 71% (d) excellent and good 95% (e) 20% (g) 84% (c) very effective and effective 80% (b) 90% (f) good and fair 59% (g) (a) Green et al. (1984) (b) Franklin and Powell (1993) (c) Andelt and Hopper (2000) (d) Green and Woodruff (1988) (e) Andelt (1992) (f) Meadows and Knowlton (2000) (g) Walton and Feild (1989)
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William F. Andelt Professor and Extension Wildlife Specialist, Department of Fishery and Wildlife biology, Colorado State University, Fort Collins, CO 80523; (970) 491-7093; (fax) (970) 491-5091; email@example.com