UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

JAN 0 6 2009 OFFICE OF 

PREVENTION. PESTICIDES AND TOXIC 

SUBSTANCES 

MEMORANDUM 

SUBJECT: Analysis of the Role of the M-44 Device and Compound 1080 Livestock 

Protection Collars in Predator Management @P # 356680 and # 356681) 

2 

FROM: Elizabeth Hill, Economist =- ( [L LO% 

T 1 Wyatt, Senior Economist ,41J3& 5 zdl 

Economic Analysis Branch 

Biological and Economic Analysis Division (7503P) 

Angel Chiri, Entomologist 

Josh Williams, Intern 

Biological Analysis Branch 

THRU: Timothy Kiely, Chief 

Economic Analysis Branch 

Arnet Jones, Chief 

Biological Analysis Branch 

Biological and Economic Analysis Division (7503P) 

TO: Joy Schnackenbeck, Chemical Review Manager 

Robert McNally, Chief 

Special Review Branch 

Special Review and Reregistration Division (7508P) 

Product Review Panel Date: November 12,2008 
TABLE OF CONTENTS: 

I . BACKGROUND ....................................................................................................................... 4 

I1 . LIVESTOCK PRODUCTION IN THE UNITED STATES ........................................ 5 

SHEEP PRODUCTION ............................................................................................................................. 5 

CATTLE AND GOAT PRODUCTION ........................................................................................................ 9 

I11 . CHARACTERISTICS OF PREDATION ON LIVESTOCK .......................................... 10 

IV . PREDATOR CONTROL TECHNIQUES ......................................................................... 13 

1 . LETHAL PREDATOR CONTROL TECHNIQUES ............................................................................. 15 

A . POISONS/TOXICANTS ............................................................................................................... 15 

B . COMPOUND 1080 LIVESTOCK PROTECTION COLLAR (LPC) ................................................... 16 

C . M-44 SODIUM CYANIDE DEVICE ............................................................................................. 19 

D . HUNTING .................................................................................................................................. 22 

E . DENNING .................................................................................................................................. 23 

F . TRAPPING ................................................................................................................................. 24 

2 . NON-LETHAL PREDATOR CONTROL TECHNIQUES .................................................................... 25 

A . GUARDING ANIMALS ............................................................................................................... 25 

B . VIGILANCE (HERDING) ............................................................................................................ 28 

c . EXCLUSION (FENCING) ............................................................................................................ 29 

D . DETERRENTS ............................................................................................................................ 31 

E . HUSBANDRY MANAGEMENT PRACTICES .................................................................................. 32 

i . Avoiding high predation areas ...................................................................................... 32 

ii . Night penning ............................................................................................................... 32 ... in . Shed lambing ................................................................................................................ 32 

iv . Sanitation (carcass removal) ......................................................................................... 33 

v . Monitoring sheep numbers (record keeping) ................................................................ 33 

vi . Altering breeding times (fall lambing) ......................................................................... 33 

F . EXPERIMENTAL TECHNIQUES .................................................................................................. 34 

V . DISCUSSION AND CONCLUSIONS ................................................................................. 34 

VI . REFERENCES ..................................................................................................................... 36 
TABLES AND FIGURES: 

TABLE 1: AVERAGE SHEEP INVENTORY. MEAT AND WOOL PRODUCTION. AND TOTAL VALUE. 

2003-2007 ............................................................................................................................................................. 5 

TABLE 2: AVERAGE SHEEP INVENTORY. NUMBER OF OPERATIONS AND AVERAGE HERD SIZE. 

2003-2007 ............................................................................................................................................................. 7 

TABLE 3: SHEEP AND LAMB OPERATIONS BY HERD SIZE ............................................................................. 8 

TABLE 4: AVERAGE CATTLE INVENTORY. MEAT AND MILK PRODUCTION. AND TOTAL VALUE. 

2003-2007 ........................................................................................................................................................... 10 

TABLE 5: AVERAGE SHEEP INVENTORY. 2003.2007. AND LOSSES. 2004 ................................................... 11 

TABLE 6: AVERAGE CATTLE INVENTORY. 2003.2007. AND LOSSES. 2005 ................................................ 12 

TABLE 7: REVIEW OF LETHAL AND NON-LETHAL METHODS FOR PREDATOR CONTROL .................. 13 

TABLE 8: LPC UNITS PUNCTURED/DAMAGED AND SUBSEQUENT COYOTE TAKES. FY02 TO FY061 18 

TABLE 9: NUMBER OF ANIMALS TAKEN WITH LIVESTOCK PROTECTION COLLARS (LPCS) BY 

WILDLIFE SERVICES. FY02 TO FY06 (BY SPECIES) ................................................................................. 18 

TABLE 10: ANNUAL DISTRIBUTION. USE. BY APHIS. & RESULTS OF M-44.200 2.2006 AVERAGE ....... 20 

TABLE 1 1 : M-44s FIRED/DISCHARGED IN THE FIELD BY APHIS. FY02-FY06 ............................................ 21 

TABLE 12: NUMBER OF ANIMALS TAKEN WITH M-44 BY APHIS WS. FY02 TO FY06 (BY SPECIES) .... 22 

TABLE 13: PERCENT OF SHEEP OPERATIONS USING GUARD ANIMALS TO PREVENT PREDATOR 

LOSSES. 2004 .................................................................................................................................................... 26 

TABLE 14: PERCENT OF SHEEP OPERATIONS USING HERDING. FREQUENT CHECKS. AND FENCING 

TO PREVENT PREDATOR LOSSES. 2004 ..................................................................................................... 29 

TABLE 15: PERCENT OF SHEEP OPERATIONS USING HUSBANDRY MANAGEMENT PRACTICES TO 

PREVENT PREDATOR LOSSES. 2004 ........................................................................................................... 33 

FIGURE 1: U.S. LAMB AND MUTTON IMPORTS FROM NEW ZEALAND AND AUSTRALIA. 2003-2007 ... 6 

FIGURE 2: U.S. SHEEP AND LAMB POPULATION. 1920-2008 ........................................................................... 9 
Summary 

A coalition of stakeholder groups has filed a petition requesting that the EPA cancel the use of 

M-44 sodium cyanide ejector devices and Compound 1080 (sodium fluoroacetate) Livestock 

Protection Collars. Although the petition provides numerous grounds for this request, the 

primary allegation is that they indiscriminately kill nontarget species, including endangered 

species. These devices are used by livestock producers as a way to control coyotes and wild dogs 

that prey on sheep and goats. The petition alleges that these devices are not essential for predator 

control because adequate alternatives exist. BEAD examined the current usage of M-44 devices 

and Compound 1080 Livestock Protection Collars as well as other lethal and nonlethal predator 

control methods. Along with differing efficacies, the degree to which these methods 

indiscriminately kill nontarget species can vary drastically. It is clear that all available methods 

play a role in predation management programs and have certain strengths and weaknesses. The 

components of a good predator management program depend on the location and unique 

predation challenges faced by individual livestock operation. BEAD concludes that the M-44 

devices and the Compound 1080 Livestock Protection Collars provide benefits to producers of 

sheep, goats, and cattle and, in the absence of these products, producers would likely incur 

higher costs andlor more livestock loss. However, BEAD is not able to quantiQ these impacts or 

estimate the number of operations that might be impacted by the proposed changes in predator 

management. Given the competitive nature of the industry, particularly in sheep production, it is 

possible that such changes could force individual producers out of business. 

I. Background 

Both the M-44 device and Compound 1080 are designed to target and kill predators of sheep and 

goats; however, only M-44 devices can be used in conjunction with cattle. These predation 

control methods target canids, especially coyotes. Coyotes are attracted to M-44 devices with 

fetid bait, and when one tries to eat it, the M-44 device ejects a lethal dose of sodium cyanide 

into its mouth, causing death within two minutes. Compound 1080 is used in livestock 

protection collars (LPC) that has a reservoir containing a 1 % solution of sodium fluoroacetate. 

Typically, the collar is fitted around the neck of a lamb or kid, although it can be used on an 

adult sheep or goat. If a coyote attacks at the neck and punctures the LPC, it releases a lethal 

dose of sodium fluoroacetate into its mouth. 

In January 2007, a coalition of stakeholder groups filed a petition requesting that the Agency 

cancel the use of both the M-44 device and the LPC. The petition was based, in part, on risk 

concerns for nontarget species, most notably those listed as being endangered or threatened. The 

petition also alleges that these devices are not essential for predator control because adequate 

alternatives exist (i.e., that there are few benefits). This document examines the merits of this 

allegation with a primary focus on the predation by coyotes on sheep, as this is how the 

predacides are most commonly used. Findings are also applicable to goat production and, to a 

lesser extent, cow-calf operations. 

This analysis is based primarily on a review of literature, documents available on the internet, 

comments submitted to the Agency by stockholders, and consultation with state officials and 

university research and extension personnel. It is qualitative in nature as it is not possible to 
accurately quantify the efficacy and cost of predator control measures. Predation problems and 

predation control are both highly dependent on localized factors, including field topography and 

the livestock production system. There may also be temporal variability within and between 

years having to do with ecosystem fluctuations, such as the availability of alternative food for 

predators and competition from other predator species. 

11. Livestock Production in the United States 

Sheep Production 

Sheep production occurs throughout the entire United States, but is concentrated primarily in the 

western region of the country. By far, Texas has the largest sheep population of any state in the 

country, with more than one million head of sheep. California, Wyoming, Colorado, and South 

Dakota also have a significant number of sheep. Together, these five states account for almost 

half of the sheep population in the United States (NASS, 2008a). 

Dozens of products are derived from sheep and sheep by-products; the most important of these 

are meat (mutton and lamb), wool, and dairy products. Table 1 presents statistics for the United 

States and key states or regions. Wool production and the value of wool vary much more 

between regions than meat production and value. For example, the West, including the High 

Plains and Mountain states, account for about 30% of the nation's sheep compared to 20% in the 

East. However, the former produces 36% of U.S. wool, by weight, and almost 45% by value, 

while states in the East produce about 18% of wool by weight and less than 8% by value. 

Arizona 

California 

Mountain West ' 

Northern Plains 

Texas 

Plains 

Pacific 

1 Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

Oregon and Washington. 

Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

109 

668 

East 

Other 

United States 

1,903 

483 

1,070 

277 

272 

3,927 

42.797 

Source: USDA NASS, 2005-2008 PDI; 

1,262 

148 

6,191 

181,844 

35,859 

5 1,955 

20,947 

16.506 

596 

3.400 

107,446 

7,002 

468,282 

14,394 

3,181 

5,210 

1,350 

1.490 

3,596 

38.639 

6,641 

538 

36,801 

136.70 

126.20 

166,296 

35,23 1 

5 1,692 

18,034 

15.329 

132.60 

134.00 

104.70 

140.30 

125.30 

96,364 

6,49 1 

43 1,672 

150.40 

133.60 

132.90 
In 2007, over 200,000 sheep and lambs were slaughtered in the United States. Of these, 2% were 

exported, primarily to China and Germany (Geisler, 2008a; Geisler, 2008~). The United States 

imports substantial quantities of mutton and lamb from Australia and New Zealand, as indciated 

in Figure 1 (USDA ERS, 2008b; USDA NASS, 2008b). However, lamb and mutton are not 

particularly popular meats in the United States. With the exception of veal (0.4 pounds), lamb 

and mutton (1.1 pounds) were the least consumed meat per capita in the United States in 2006. 

Instead, the average American prefers other types of meat, consuming about 87 pounds of broiler 

chicks, 66 pounds of beef, 50 pounds of pork, and 17 pounds of turkey, per capita in 2006 

(USDA NASS, 2008b). 

Figure 1: U.S. Lamb and Mutton Imports from New Zealand and Australia, 2003-2007 

Year 

USDA ERS. 2008b 

Sheep are also raised for wool, and to a lesser extent, milk. Wool production has been steadily 

declining over the past decade, with 4.7 million head of sheep (35 million pounds of greasy 

wool) being shorn in 2007, compared to nearly 7.0 million head in 1997 (nearly 56 million 

pounds of wool). Competition with other natural fibers, changes in consumers' tastes and 

preferences, and the loss of price supports for the U.S. wool industry (e.g., the National Wool 

Act) have all led to the decline in wool production (USDA NASS, 2008). Sheep milk is 

primarily used to make cheeses, such as feta and Roquefort. Such practices were only started in 

the United States in the 1980s, and today only an estimated 75 to 100 dairy sheep farms exist 

nationwide (Geisler, 2008b). Reasons cited for this small number include the relatively high risk 

nature of this industry, coupled with high start-up and labor costs (Hale and Coffey, 2006). In 

comparison, dairy goats have proven to be a much more vital industry with an estimated one 

million head of dairy goats in the United States producing 50 million kg of milk annually, 

whereas a slightly over ten thousand ewes in the United States and Canada produce 2 to 2.5 

million kg of milk annually (Thomas and Haenlein, 2005). 
In addition to the value of meat, wool, and dairy products, sheep production engenders other 

benefits for the United State's economy. For example, one 2008 study estimated the total 

economic impact of the sheep industry by using an input-out model (Trinidad, 2008). The study 

quantified the benefits associated with transactions within the supply chain, incomes received by 

employees in the industry, expenditures both on the goods and services provided to consumers, 

and a "ripple effect" from increased expenditures in local communities. Trinidad finds that 

every $1 .OO of lamb produced yielded $1.80 of benefits within the industry and $0.84 in 

additional spending within the local economy. Furthermore, for every 25 jobs created in the 

sheep industry, 10 jobs are created in associated industries, such as feed stores, while six jobs are 

created as a result of increased consumer spending by sheep industry related persons. 

Sheep operations vary considerably by the region of the country. Operations in Eastern states are 

typically much smaller, with an average flock size of less than 50 head, while flocks in states in 

the West average more than 200 head (Table 2). Pasture conditions also influence production 

arrangements, with arid regions including Arizona, and the Mountain and the Plains states, which 

generally require more land per sheep than in the East, California, and the Pacific regions. 

Table 2: Average Sheep Inventory, Number of Operations and Average Herd Size, 2003- 

2007 

Number of Ranches 

Source: USDA NASS, 2005-2008; 

1 Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. 5 Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

While the state and regional averages vary considerably, most sheep operations tend to be small. 

Approximately 90% of sheep farms in the United States have fewer than 100 head; however, 

large productions with 1,000+ head can be found in areas such as Texas and the Mountain West, 

as shown in Table 3 (NASS, 2002). 
The United States has faced a drastic reduction in sheep operations, with the number of 

operations dropping fi-om 1 1 2,580 in 1986 to 72,680 in 1997-more than a 3 5% decrease 

(Geisler, 2008c; NASS 2008e). This decline has slowed in recent years with 70,590 operations 

in 2007, implying less than a 3% decline since 1997. With this overall decline in the number of 

operations, the total sheep population in the United States has dwindled. From its peak in 1942 of 

56 million head, the sheep population has decreased by more than 78% to 6 million head 

nationwide in 2008, as seen in Figure 2 (NASS 2008a; Geisler, 2008~). Sheep numbers have 

continued to decline in the United States, with a decrease of more than 20% in the last decade. A 

similar trend can be seen in states that have state-limited registrations for the use of M-44s and 

1080s, which have had a 29% decrease in their sheep population fiom 1997-2007, and an 8% 

decline in the number of operations. Although predation has often been viewed as a major cause 

of livestock loss, the overall decline in the industry can be largely attributed to changes in 

consumers' tastes and preferences and increased land and hay prices (Berger, 2006). 

East 3 

Other 

United States 

Source: NASS, 2002 ' Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. 

Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

21,001 

5153 

44,562 

10,3 84 

1,278 

20,664 

2,254 

155 

5,670 

433 

23 

1,995 

58 

5 

893 
Figure 2: U.S. Sheep and Lamb Population, 1920-2008 

60,000 

50.000 

1 40,000 

30,000 V 

II 3 20,000 

10,000 

0 

@&86dop'op 2 \ &Q8& 2 kc3 2 \ 

.................... 4 4 &&% &@@@ 

Year 

Source: NASS, 2008a 

Cattle and Goat Production 

Cattle production, like sheep, is conducted throughout the United States. Cattle and sheep 

production often co-exist and will exploit the same or similar grazing land, particularly in the 

Western United States where production systems are characterized by extensive grazing on 

marginal land. 

Cattle production provides significant value in meat and milk. Table 4 presents statistics on the 

number of cattle and the value of production. Production of the two commodities varies 

significantly by cattle breed and by system of production. Milk is the primary commodity in 

California, the Pacific, and most of the East, particularly Michigan. Generally, the dairy system 

is much more concentrated than beef production and requires significant input of forage and 

other feed. Beef is more important in the Mountain and Plains states where the production 

system often relies on extensive grazing and few inputs until the cattle are sold to feed lots where 

they are fattened for slaughter. 
Table 4: Average Cattle Inventory, Meat and Milk Production, and Total Value, 2003-2007 

S tate/Region 

Arizona 

California 

Mountain ' 

Northern Plains 

Texas 

Plains 

Pacific 

East 

' Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. 

Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

6 Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, and South Carolina. 

Cattle 

(1000 

head) 

898 

5,360 

1 1,324 

5,482 

13,940 

18.230 

Southeast 

Other 

United States 

Statistics on goat production are limited. The main commodities in goat production are meat, 

dairy products such as specialty cheeses, and the wool, specifically mohair. 

2,506 

29.138 

111. Characteristics of Predation on Livestock 

Meat 

(Ioo0 lb :ve 

weight 

585,944 

1,974,627 

5,609,614 

2,252,776 

7,217,146 

10.612.379 

Source: USDA NASS. 2005-2008 

8,398 

750 

96,026 

Predation on Sheep 

1,160,870 

9.613.790 

Sheep and goats in the United States are subject to predation by cougars, wolves, coyotes, dogs, 

bobcats, lynxes, bears and, to a lesser extent, wolves, foxes, eagles, ravens, and vultures. Sheep 

are especially vulnerable to predation because aside from running, they have no means of 

defending themselves. In 2004, approximately 66,400 sheep and 157,800 lambs were lost to 

predators out of an estimated total population of 6.1 million sheep and lambs. This number 

represents 37.3% of sheep and lamb death losses that year (APHIS WS, 2007). In 2004, 

predation by coyotes and dogs accounted for 51.7% and 22.7% of the sheep and lamb losses, 

respectively (APHIS WS, 2007). This implies that, in sum, coyote predation accounted for 

50,893 sheep and 1 15,911 lamb deaths that year. Again, differences arise across regions of the 

country, with predation losses and losses to coyotes relatively high in the west, especially in the 

Mountain States of Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming, in 

Texas, and in the Pacific. Losses are relatively low in Arizona, California, and the Eastern 

United States (Table 5). Among Eastern states, West Virginia stands out as having substantially 

higher losses to coyotes on average. The high predation in some areas of West Virginia may be 

due to the state's terrain, which provides natural cover .and a better habitat for coyotes. 

Milk 

Production 

(1,000,000 lb) 

3,821 

37,796 

22,181 

1,938 

6,521 

4.547 

2,528,012 

162,871 

41,7 18,029 

7,761 

82.758 

Total Value 

($1000) 

1,044,202 

6,507,339 

8,300,438 

2,401,23 1 

7,129,004 

9.5 19.465 

5,225 

4,584 

177,131 

Value per 

Head 

($1 

1,020 

1,165 

1,055 

1,040 

790 

865 

2,192,214 

20.940.878 

1,040 

950 

2,996,787 

868,422 

61,899,98 1 

785 

1,180 

93 0 
Table 5: Average Sheep Inventory, 2003-2007, and Losses, 2004. 

I State 

(1000 head) 

1 Other 148 20,600 5,500 1 1,900 1 1.3 

Sheep I Losses, All / Losses to I Losses to I Loss to I 

Arizona 

California 

Mountain West ' 

Northern Plains 

Texas 

Plains 

Pacific 

East 

West Virginia 

I United States 6,191 600,300 224,200 1 135,600 1 2.2 

Source: USDA NASS, 2005-2008; USDA 2005. 

Causes 

(head) 

1 Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. * Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

109 

668 

1,903 

483 

1,070 

277 

272 

1,262 

34 

Predation is also highly variable within regional areas. Nunley (1 995) reports that coyote losses 

in Texas averaged only 0.4% of the sheep population and 1.7% of lambs. However, the 

distribution of losses is very inconsistent with 54% of producers experiencing no losses, while 

12% of producers suffered losses in excess of 10% of their herd. Factors that influence the 

degree of predation include field topography, with more rugged terrain enabling coyotes to more 

easily stalk sheep; large fields; availability of other prey; and even individual predator behavior 

(Tirnrn and Connolly, 200 1 ; O'Gara and Rightmire, 1987). 

Predators 

(head) 

Non-predator losses include disease, weather, and accidents. The petitioners allege that these 

losses are greater than those caused by predators, and that there is little to no benefit arising from 

predator control. However, this comparison is flawed as losses due to other causes other than 

predation are irrelevant to the benefits assessment of M-44 or LPCs. The impact of canceling M44 and LPCs would be the additional livestock losses andlor the added cost of predator control 

that producers would face in the context of existing losses for other reasons. 

4,000 

26,000 

162,000 

49,000 

99,000 

37,000 

2 1,000 

181,700 

7.500 

Coyote predation on sheep and lambs tends to increase during the spring and summer, 

throughout the period when coyotes are rearing pups and have a greater need for food. Lambs 

are especially vulnerable to predation by coyotes during this time because most of them are born 

during this season. Radiotelemetry studies suggest that most predation on sheep is done by 

select groups of breeding pairs characterized as territorial "alpha" coyotes (Sacks et al., 1999; 

Tirnrn and Connolly, 2001). Coyotes also tend to attack their prey at the throat. O'Gara et al. 

(1 983, cited in Connolly and Burns, 1990) reported that 74% of coyotes attacked the neck or 

Coyotes 

(head) 

Coyote 

(% sheep) 

2,000 

1 1,000 

88,500 

10,700 

57,000 

8,600 

10,900 

30,000 

3.300 

1,100 

7,200 

59,000 

8,900 

29,500 

5,200 

7,200 

15,600 

2.100 

1 .O 

1.1 

3.1 

1.8 

2.8 

1.9 

2.7 

1.2 

6.3 
throat when killing sheep, while Nass (1977, cited in Connolly and Burns, 1990) reports that 

82% of kills exhibit neck or throat wounds. 

Goat losses are similar to sheep with about 40% of losses in kids and 30% of losses in adults 

attributed to predators in 2004 (USDA NASS, 2005). The value of losses to predators amounted 

to $16 million in 2004. 

Predation on Cattle 

Cattle suffer relatively lower rates of predation than sheep as they are larger and better able to 

defend themselves. However, given the number of cattle relative to the number of sheep and 

goats, the absolute number of cattle lost to coyote predation is similar to losses in sheep and of 

much greater value. See Table 6. Losses of cattle to coyotes are valued at $43.9 million (USDA, 

2006). 

Table 6: Average Cattle Inventory, 2003-2007, and Losses, 2005. 

I State 

Cattle I Losses, All I Losses to 1 (1000 bead) Causes Predators 

Plains 

Pacific 

Losses to 

Coyotes 

East 

Southeast 

' Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 2 North Dakota and South Dakota. 

3 Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. 

Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

6 Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, and South Carolina. 

Loss to 

Coyote 

18,230 

2.506 

Other 

United States 

As indicated in Table 6, cattle losses to coyotes as a percentage of cattle are greatest in the 

Southeast, an area with very limited sheep production. Beyond that, a similar pattern of losses 

emerges in cattle as with sheep, with relatively higher losses in Texas, in the Pacific, and in the 

Mountain states. 'Losses diminish in the open plains and in the East. 

29,138 

8.398 

610,000 

109.000 

Source: USDA NASS, 2005-2008; USDA 2006. 

750 

96,026 

1,442,000 

347.000 

1 8,900 

7.000 

33,000 

4,05 1,000 

45,100 

38.700 

9,400 

2.900 

900 

190,000 

0.05 

0.12 

22,800 

18.800 

0.08 

0.22 I - - 

600 

97,000 

0.08 

0.10 
IV. Predator Control Techniques 

The main objective of a predator control program is to reduce the losses that predators impose on 

livestock. If the cost of predator control is less than cost of losing livestock to predators, a 

predator control program can have a positive impact on a livestock producer's economic wellbeing. Programs typically encompass a range of activities, including avoiding predators, 

deterring attacks, and removing predators. Predator management is dependent on a variety of 

factors outlined in Section I11 of this document. 

Comments submitted to the Agency suggest that many producers rely on a mix of predator 

management techniques, both lethal and nonlethal, to protect livestock from predation by coyotes 

and dogs1. Non-lethal methods include the use of guard animals, herding, fencing, deterrents, 

and husbandry practices. In some cases, predation is unmanageable with the use of non-lethal 

methods, and livestock producers must depend on lethal control methods. A short summary of 

both lethal and non-lethal techniques is provided in Table 7. Common lethal predator control 

methods include poisons and toxicants, hunting, denning (a predation control strategy that seeks 

to eliminate entire coyote family units, including pups in dens), and trapping. The use of any 

combination of predator control techniques is sometimes described in the literature as integrated 

predator management ("IPM). For instance, in discussing the role of guarding animals, 

Wilbanks (1995) states that donkeys are "... compatible with most traditional methods of 

predator control and can be used in an integrated predator management program." Similarly, 

according to Franklin and Powell (1994), the best protection to livestock is accomplished 

through an IPM program that includes both preventive (i.e., nonlethal methods) and selected 

lethal control methods, since it is likely that no single method is fully effective by itself. 

Table 7: Review of Lethal and Non-Lethal Methods for Predator Control 

' These methods are described in detail in Sections IV. 1 and IV. 2. 

13 

Predator 

Control 

Methods 

"Efficacy" Considerations Comments/Drawbacks 

These devices may fail at times. They also 

require frequent inspections and regular 

maintenance. 

A lamb is lost for every predator that is taken. 

This method is time-consuming and may 

require the services of skilled hunters. Aerial 

hunting can be expensive. 

Although, technically, these are not lethal tools, 

all trapped coyotes are quickly killed. Trapping 

is method that requires a great deal of skill and 

experience. 

This method is time-consuming and may 

require a great deal of tracking and hunting 

skills. 

Lethal 

M-44 device 

1080 LPCs 

Hunting 

TrapsISnares 

Denning 

Relatively effective, but not selective, 

as it will kill any canid predator 

attracted to the scent whether it is the 

offending predator or not. 

Effective and highly selective in that it 

kills a predator only after it initiates an 

attack on a lamb. 

Effective but not selective, since the 

hunter may not necessarily target 

sheep-killing predators. 

Relatively effective, but not selective, 

although selectiveness increases when 

the traps or snares are set only at or 

near the site of a recent kill. 

Effective, as long as only dens of 

offending coyotes are targeted. 
The lethal predator control methods discussed in this paper are not readily comparable, as each 

represents a different control tactic. Although these techniques directly (M-44s, LPCs, shooting) 

or indirectly (traps and snares) result in the death of offending canids, they all have distinctive 

characteristics that would preclude direct efficacy comparisons. M-44s, traps, and snares are all 

stationary devices that rely to a large extent on the selection of the placement site. That is, they 

are most effective when placed on or near the site of a previous killing or in the path of a 

predator. The proper setting of traps and snares requires a great deal of skill that only comes 

from practice and experience. Still, older, experienced coyotes can learn to avoid these devices. 

These methods require investing time and labor to set the devices and to inspect them on a 

Nonlethal 

Guarding animals 

(dogs, llamas, 

donkeys) 

Herdinglvigilance 

Fencing 

Deterrents (sound 

and light-emitting 

frightening 

devices) 

Avoidance of 

high predation 

areas 

Night penning 

Shed lambing 

Sanitation 

(carrion removal) 

Fall lambing 

Monitoring 

Fairly effective for smaller operations. 

Effectiveness may vary with the 

individual guarding animal. Best used 

in conjunction with other methods, such 

as fencing. 

Effective when the herders are skilled 

and alert. Effectiveness is also related 

to flock size. 

Effective when properly constructed 

and maintained. Works best for smaller 

operations and when used in 

conjunction with other nonlethal 

methods. 

Effective for short periods (weeks to a 

few months). Work best with smaller 

operations and when used in 

conjunction with other nonlethal 

methods such as fences. 

Avoiding such areas will likely reduce 

the risk of predation. 

Herding flocks into enclosures each 

night reduces the risk of predation. 

Works best with smaller operations. 

Probably very effective in protecting 

lambs during their first few months of 

life. 

The prompt removal of carrion is meant 

to avoid attracting predators and reduce 

the risk of predation. 

Shifting sheep breeding to May-June so 

that lambs are born in fall rather than in 

spring decreases the high risk of 

predation that occurs during spring, 

when coyotes are raising pups. 

Producers who check sheep numbers 

fi-equently are able to detect losses and 

take appropriate actions before too 

many sheep are lost. 

Dogs need to be raised and imprinted with 

sheep. Vigilance traits vary from dog to dog. 

Guarding dogs have a relatively short life span 

and must be replaced frequently. Llamas and 

donkeys often become effective guarding 

animals, but may not accept guarding or 

herding dogs. 

Experienced herders may not be easily found, 

and their services may be cost-prohibitive or 

impractical for some producers. 

Impractical for large operations that extend 

over many square miles and/or where the 

terrain is highly irregular. High maintenance 

cost. 

Predators eventually get used to these devices 

and ignore them. The loud sounds produced by 

gas cannons and electronic devices after dark 

may disturb neighbors. 

This approach may interfere with the effective 

utilization of pastures or other livestock 

practices. 

Not a practical measure for the larger 

operations. 

Because of logistics and labor costs, this 

practice is more suitable for smaller operations. 

This measure may be impractical for the larger 

operations. 

Fall lambing may not be compatible with range 

conditions and marketing strategies. Also, the 

natural estrus cycle of ewes must be artificially 

altered, and this is a costly procedure. 

This is not always practical, especially for large 

operations. Complex topography and extensive 

grazing lands can make it hard to get accurate 

counts on a regular basis. 
regular basis. Outfitting a herder with a fire arm for use against approaching predators can also 

be considered a stationary method, as it would not require the herder to actively hunt predators. 

The use of LPCs is relatively unique in comparison to other control tactics. Essentially, a group 

of lambs wearing LPCs is used as bait. If a coyote attacks one of the collared lambs and 

punctures the LPC, both the coyote and lamb will usually die, since the coyote will kill the lamb 

before it succumbs to the effects of the poison. Although this approach is highly specific to 

taking confirmed predators rather than nontarget species, there is no assurance that the lambs 

outfitted with the collars will be attacked. LPC effectiveness is also difficult to measure, with 

several unprotected lambs possibly being killed before one wearing an LPC is attacked. 

Ground and aerial hunting, as well as denning, require the active pursuit of predators by skilled 

individuals. These activities are generally used as last resort options when stationary methods 

have failed to take known predators. Whereas stationary lethal methods can be used for 

extended periods, hunting tends to be a focused, time-limited activity. 

Nonlethal predator management techniques, on the other hand, aim at decreasing the risk of 

predation through livestock protection measures. For example, guard animals, fences, and 

predator deterrent devices can be used singly or in various combinations. Depending on the 

location, these methods may effectively decrease, although not totally, eliminate predation. 

Lethal and nonlethal control methods are not necessarily replacements for each other, but are 

rather different tactics that in some situations can be integrated for better results. 

A primary uncertainty in this analysis is the difficulty in fully accounting for the costs of various 

control measures, which include direct and indirect costs. Throughout this analysis, BEAD 

presents information it obtained about direct costs of predator control techniques, which 

primarily include material costs. However, even these costs are difficult to interpret and quantify 

in terms of a typical analysis done to compare pesticides, which are often highly substitutable. 

The cost of traps or fencing per mile is not necessarily informative without knowing the specifics 

of a location that determine the necessary number of traps or the length of fencing. Indirect 

costs, especially labor, are extremely difficult to quantify as the level of effort required or 

expended may be a function of local conditions, such as terrain and weather, and is also likely to 

be a function of the level of predation or threat of predation. For these reasons, BEAD can 

characterize certain situations but is unable to draw clear conclusions as to the economic 

feasibility of particular predator control techniques. 

1. Lethal Predator Control Techniques 

The only three active ingredients specifically registered for coyote control in the United States 

are sodium cyanide, sodium fluoroacetate, and sodium nitrate. Sodium cyanide is used in M-44 

ejector devices, sodium fluoroacetate is used with LPCs, and cartridges containing sodium nitrate 

and charcoal are used to produce carbon monoxide inside coyote dens (Fagerstone et al., 2003). 

Both sodium cyanide and sodium fluoroacetate are restricted-use pesticides registered by the 
EPA and can only be applied by certified applicators. Sodium nitrate is not a restricted-use 

pesticide and therefore can be applied by non-certified applicators. 

The U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) is 

the primary applicator of M-44s and LPCs in most states, although states that have cooperative 

agreements with APHIS often have a high proportion of applicators being certified by the state. 

For example, the Texas Department of Agriculture, which has a cooperative agreement with 

APHIS, has certified 1,135 M-44 applicators, while only 172 M-44 applicators in Texas are 

directly certified by APHIS' Wildlife Services (TDA, 2008). 

The petitioners allege that APHIS fails to assist livestock producers with non-lethal controls and 

therefore perpetuates the use of poisons. However, APHIS wildlife management encompasses a 

number of alternatives. For example, APHIS research developed the "Electronic Guard," a 

frightening device that has proven useful in reducing sheep predation by coyotes. The 

petitioners further allege that the APHIS predator control program is a burden to taxpayers when 

the decline of the sheep industry is not caused by predation (Berger, 2006). While it is clearly 

the case that market forces are largely responsible for the decline in the sheep industry, predator 

control makes an important contribution. According to Berger (2006), federal and cooperative 

funding on livestock protection is positively and significantly associated with greater numbers of 

sheep. Regression results indicate that a $1,000 expenditure on predator control leads to an 

increase of nearly 70 sheep, on average, with a value of around $9,300, given the estimated value 

per head shown in Table 1 ($1 32.90). 

b. Compound 1080 Livestock Protection Collar (LPC) 

The LPC is designed to selectively target and eliminate predators that initiate an attack on small 

livestock. A LPC consists of two rubber bags, each containing 15 ml of a 1 % solution of sodium 

fluoroacetate. It is attached to a collar-like strap that is placed around the neck of a lamb or kid 

so that the bags lay beneath the throat, just behind the jaw (Rollins, 1995). When a coyote 

attacks a lamb or goat wearing the collar, it will likely tear it and release the toxicant into its 

mouth, causing its death within a few hours. 

Sodium monofluoracetate is only distributed through the predacide's sole registrant, APHIS 

(EPA, 1995). The LPC is permitted in five states: Montana, New Mexico, South Dakota, Texas, 

and Wyoming (EPA, 1995). Of these, New Mexico and Texas are the only states that actively 

use Compound 1080. Scattered use can be seen throughout states that do not hold state-limited 

registrations, such as West Virginia, which must obtain written permission from the U.S. Fish 

and Wildlife Service prior to application. California and Oregon banned the use of Compound 

1080 in 1998 (EPA, 1995; USDA APHIS, 2008b). 

The 1995 RED for sodium monofluoroacetate specifies that LPCs cannot be used in pastures that 

are greater than 2,460 acres (4 mi2) unless rainfall in the area averages less than or equal to 20 

inches; then, LPCs can be used in pastures up to 10,000 acres (1 6 mi2). Additionally, restrictions 

exist on the number of collars per acre, with a limit of 20 collars per 100 acres, 50 collars per 101 

to 640 acres, and 100 collars per 641 to 10,000 acres. The collars must be checked weekly, 

weather permitting. 
Studies show that the efficacy of LPCs is highly dependent on (1) if the sheep are kept in a pen 

or a field and (2) the ability to direct coyote predation to collared individuals. In pen tests, 

Connolly and Burns (1990) found that coyotes attacked sheep over 75% of the time when given 

the opportunity. Of 41 attacks, 36 were to the neck and throat area and resulted in 26 punctures 

to the collars and 24 coyotes killed. That is, collars were punctured in 63% of all attacks and in 

72% of neck and throat attacks. Coyotes succeeded in killing 34 lambs. In field tests, 32 attacks 

or 48%, of which 64% were neck and throat attacks, resulted in punctured collars. Only three 

coyotes were confirmed dead, including one found nearly a mile away (Connolly and Burns, 

1990). A field study in New Mexico found a 50% puncture rate on collared sheep (Wade and 

Connolly, 1980, cited in Connolly and Bums, 1990) while a study with goats in Texas reported a 

puncture rate of 83% (Littauer, 1984 cited in Connolly and Burns, 1990). Targeting was 

achieved by placing flocks with collared lambs in areas of recent predation losses2. Even though 

the collared lambs amounted to only about 3% of the flock, roughly half of the coyote attacks 

involved collared individuals (Connolly and Burns, 1990). Targeting may be relatively easy, if 

certain locations are more conducive for coyotes to hunt. Localized predation may also be due to 

specific coyotes. In the pen tests, four of the 24 coyotes killed were involved in multiple attacks, 

including one coyote that attacked five lambs before puncturing a collar. 

LPCs cost around $25 each (USDA PSD, 2008). This does not account for the costs of 

maintenance or other labor costs, but it is likely that they are significant since the 1995 RED for 

sodium monofluoroacetate specifies that they must be checked weekly by certified applicators or 

by persons under their direct supervision (EPA, 1995). Furthermore, for an LPC to be successful, 

a sheep or lamb will probably be lost in the attack. With the average sheep or lamb valued at 

$138/head in 2007, such livestock losses could have severe economic impacts on producers 

(USDA NASS, 2008e). Although LPCs are recognized for being one of the most selective forms 

of coyote control (i. e., it targets offending coyotes), limitations outlined in the 1995 sodium 

monofluoroacetate RED on the number of sheep that can be collared within a flock as well as the 

time and money involved in using them has led to a very small proportion of total sheep 

producers in the registered states actually using them (Table 8). 

2 All ranches participating in the tests had incurred at least two losses to coyotes within the previous 

week. 
Punctured1 Coyote Punctured1 Coyote Punctured1 Coyote Punctured1 Coyote Punctured1 Coyote Punctured1 Coyote 

Damaged takes Damaged takes Damaged takes Damaged takes Damaged takes Damaged takes 

NM~ 15 2 52 4 18 3 16 2 34 4 27 3 

PA - - 3 0.6 0 

TX 115 29 74 22 84 27 87 23 55 23 83 24.8 

VA 3 1 3 6 2.4 0.2 

WV 12 10 13 9 14 14 25 22 20 14 16.8 13.8 

Total 145 42 142 35 116 44 134 47 112 41 132 41.8 

Source: USDA, 2008b; APHIS WS, 2002-2006. 

It is likely that the number of coyote takes presented in this table is underestimated. This is because 

death does not occur instantly, and recovery of the carcass may not be possible. 

This data is from LPC use reports, while data for other states is from APHIS WS program data 

reports. 

Additionally, since only a certain number of sheep in a flock are allowed to wear a collar, a 

producer cannot know how many sheep will be lost before the offending coyote attacks a sheep 

that is wearing a LPC. For example, 47 coyotes were taken with LPCs in 2006 (Table 9) 

(APHIS WS, 2006; USDA, 2008b). With over 80,000 coyotes being taken by Wildlife Services 

during this year, LPCs only account for 0.06% of all coyote takings (USDA, 2008b). 

Table 9: Number of Animals Taken with Livestock Protection Collars (LPCs) by Wildlife 

Services, FY02 to FY06 (by species) 

LPC TMN', Number PuncturedlDamaged, and Species Take by APHIS WS Program nationwide 

Fiscal Year FY02 FY03 FY04 FY05 FY06 Average 

WS LPC TMN 44.5 48.1 58 52.4 62.8 52.4 

LPCs Damaged 145 142 117 1 34 113 132 

# LPCsKMN 3.3 3 2 2.6 1.8 2.6 

Target Take 

Coyote 43 40 47 52 47 47 

Nontarget take 

Bobcat 1 - - 0 

Feral Dog - - 0 

Total All Take 44 40 47 52 47 47 

Species per TMN 

CoyotesKMN 1 0.8 0.8 1 0.7 0.9 

NontargetrrMN 0.02 0 0 0 0 0.01 

% Nontargets 2.30% 0% 0% 0% 0% 0.80% 

Comparison of LPC Coyote take with All APHIS WS Take 

All WS Coyote 86,348 75,714 75,622 72,751 87,476 82,023 

LPC Coyotes 43 40 47 52 47 47 

% fo WS take 0.05% 0.05% 0.06% 0.07% 0.05% 0.06% 

Source: USDA, 2008b 

I Thousand Method Nights. TMN is a standard gauge of efficacy and is calculated as the number of 

control devices (e.g., trap) placed times the number of nights in which it is operable, divided by 1000. 

As mentioned, the LPC is mostly used when predation is already occurring and focuses on 

eliminating particularly aggressive coyotes. Therefore, it is unsurprising that there is little 
demand for the product in areas with relatively low levels of predation, such as Arizona and 

much of the East (see Table 5). There are notable exceptions, especially West Virginia, to this 

statement. Losses to coyotes in West Virginia are 6.3% of inventory, an exceptionally high rate. 

The Appalachians may be excellent coyote territory; data show that Virginia and Tennessee also 

have high loss rates compared to other Eastern states. According to Rollins (1 999, a target flock 

(i.e., one placed in an area to draw coyote attacks) should consist of about one collared lamb to 

between five and ten adults. Given restrictions on number of LPCs that can be used for a given 

area, they may be less practical for large producers who cannot easily separate their flock 

between pastures and more practical for large producers who can isolate a small group as bait in 

a predation prone area. The collars are also likely to be useful for producers with small flocks 

who can collar most of their lambs, such as in West Virginia. The toxicant is permitted in a 

small number of states, of which Texas and New Mexico are the greatest users. 

c. M-44 Sodium Cyanide Device 

M-44 cyanide capsules are labeled for use in the M-44 ejector device to control for coyotes, red 

fox, grey fox, and wild dogs that are suspected of preying on livestock. The ejector is springactivated and designed to thrust sodium cyanide into the mouth of a coyote as the animal bites 

and pulls the cyanide capsule holder, which is baited with fetid meat. Sodium cyanide reacts 

with moisture in the animal's mouth, releasing hydrogen cyanide gas and causing death within 

two minutes (APHIS, 2002). The device is anchored to the ground and placed in or near areas 

fi-equented by coyotes. 

The M-44 device is widely used to take coyotes and other canids in several states. The sole 

source for sodium cyanide is the USDA, but Montana, Wyoming, New Mexico, and Kansas Fish 

and Game Department all hold state-limited FIFRA 8 3 registrations. Area-limited registrations 

include the Navajo Nation in Arizona, as well as the Texas Department of Agriculture. Capsules 

can be entrusted to APHIS or any agency working under a cooperative agreement with a 

registered user (EPA, 1994). 

The U.S. Department of Agriculture's Pocatello Supply Depot in Idaho is the main supplier of 

M-44 capsules. During the fiscal years of 2003 to 2007, the average number of M-44 units sold 

annually in the United States was approximately 38,000 to Wildlife Services, while around 3,700 

units were sold to State Departments (EPA, 1994; USDA APHIS, 2008). As seen in Tables 10 

and 1 1, Texas is by far the largest user of M-44 devices, firing an average of 13,770 M-44s 

annually fi-om 2002-2006. Oklahoma was the second largest, with an average of 3,228 fired 

during this time period. Overall, an average of 25,264 M-44s were fired or discharged and of 

these, around 60% (1 7,647) resulted in a take (USDA APHIS, 2008b). 
The 1994 RED for sodium cyanide states that no more than 10 units per 100 acres of pastureland 

or 12 units per square mile of open rangeland are allowed. Like LPCs, M-44 devices must be 

checked every seven days by an APHIS employee or certified applicator. Furthermore, they can 

only be placed within a seven mile radius of any area where losses of livestock are reasonably 

expected unless endangered species are within the area. 

Table 10: Annual Distribution, 

State 

Arizona 

California 

Colorado 

Idaho 

Montana 

North Dakota 

Nebraska 

New Mexico 

Nevada 

Oklahoma 

Oregon 

Texas 

Utah 

Virginia 

Wyoming 

United States 

M-44s are fairly selective in that they are outfitted with bait that is designed to attract canids. M44s are useful in that once they are set, they retain their lethality potential for long periods of 

time, with little additional human intervention. In a sense, they can be compared to traps and 

snares, in that these also remain effective for long periods of time, with little human intervention, 

other than periodic checking. M-44s are especially useful in the winter months, when the 

availability of natural food for coyotes is limited and traps and snares become less effective as 

soil freezes. Conversely, M-44s are less effective in the summer, when coyotes have access to 

abundant natural food. In addition to weekly checks, M-44s do require some regular 

maintenance, as these devices are subject to mechanical malfunctions. Cyanide capsules also 

tend to absorb moisture and cake over time, becoming ineffective (Green et al., 2005). 

Source: USDA, 2008b. 

1 M-44s distributed are for 2003-2007. 

Use, by APHIS, & Results of 

M-44 Distributed ' 

70 

80 

140 

260 

1,480 

1,450 

1,700 

2,860 

220 

5,730 

700 

19,330 

1,850 

1,520 

2,630 

41,890 

M-44,2002-2006 average. 

M-44 Fired - 

29 

59 

54 

183 

798 

837 

1,656 

1,558 

9 1 

3,228 

230 

13,770 

674 

876 

668 

25,264 
Table 11: M-44s firedldischarged in the field by APHIS, FY02-NO6 

M-44 FiredlDischarged by the WS Program nationwide' 

State FY02 FY03 FY04 FY05 FY06 Average 

AZ 109 0 28 0 6 29 

CA 72 70 54 50 48 59 

ID 288 187 173 114 152 183 

MT 1,169 802 667 672 682 798 

NE 2,407 2,158 1,438 1,316 96 1 1,656 

NM 1,780 1,800 1,359 1,348 1,502 1,558 

OK 3,722 3,558 3,460 2,799 2,599 3,228 

OR 335 224 158 116 31 7 230 

TX 12,651 14,064 13,829 12,603 15,703 13,770 

WY 1,202 588 495 543 51 2 668 

Total 27,062 26,089 24,326 22,852 25,993 25,264 

Source: USDA. 2008b. 

1 The numbers presented will not match the total, as the states presented are a selection from the total 

use. For all of the states that firedldischarged M-44s, please see USDA (2008b). 

2 M-44 was banned in California, but may still be used on tribal lands. 

Efficacy data on M-44s is limited and difficult to interpret. Phillips and Blom (1994) found that 

using different scents, the average pull rate by coyotes on M-44s was 27%, that is, 58 pulls out of 

2 15 coyote visits. Certain attractants resulted in pull rates as high as 36%. The study was 

conducted during the summer months when use of M-44 is often discontinued due to low pull 

rates. In another study, 86% of sheep producers sampled in Oregon found that taking coyotes 

with M-44s provided at least some relief from predation. Coyote distribution also appears to 

play a large role in the efficacy of M-44s, with 41 % of coyote takings occurring on 10% of 

ranches (Nass, 1980). 

Some alternatives to M-44s have been noted for being more effective. Guthrey and Beasom 

(1 978) found that in terms of capturelpull rates, leghold traps were most effective, followed by 

cable snares and M-44s3. This study also noted that although M-44s are more effective in the 

short run in terms of capturelpull rates, steel traps have a higher catch-per-unit ratio. 

Disadvantages of M-44 Devices 

There are several drawbacks to the use of M-44 devices. First, M-44 devices can sometimes 

malfunction or even discharge in the absence of predators, which can lead to accidental takes. 

Second, the bait may attract and be activated by nontarget carnivores, such as domestic dogs, 

foxes, or wolves. Non-canids have also been found to pull M-44s. One study on attractants 

found that 8.6% of cattle visiting a M-44 pulled it, although there was no active ingredient in the 

devices for the study (Phillips and Blom, 1994). The authors suggest that herbivores may have 

been attracted to salts in the attractants or merely to the top of the device emerging from the 

ground as no effort was made to make them less accessible to non-predators. However, M-44s 

Pull and capture rates are typically calculated by dividing the number of pulls by the number of M-44 nights, 

where an M-44 night is the number of M-44~ placed times the number of nights in which the M-44 is operable 

(Guthrey and Beasom, 1978). 
placed by Wildlife Services are relatively selective overall, with 90% of animals taken by them 

being coyotes and over 95% of takes consisting of target canids, as seen in Table 12. 

Table 12: Number of animals taken with M-44 by APHIS WS, FY02 to FY06 (by species) I Species FY02 FY 03 FY04 FY05 FY06 Average % of Total ] 

Target take 

Coyote 14,832 13,046 11,586 1 1.667 12.596 12.745 89.67% 

~ed Fox539 400 330 287 320 375 2.64% 

Gray Fox 276 353 1 84 185 376 275 1.93% 

Feral Dog 45 34 35 30 49 39 0.27% 

Subtotal 15,692 13,833 12,135 12,169 13,341 13,434 94.51 % 

Nontarget Take 

Raccoon 31 8 331 29 1 21 8 199 271 1.91 % 

Gray Fox 102 156 93 116 87 111 0.78% 

Striped Skunk 110 167 113 59 77 105 0.74% 

Opossum 82 83 96 64 113 88 0.62% 

Red Fox 91 55 69 71 76 72 0.51 % 

Feral Dog 76 68 83 60 63 70 0.49% 

Kit Fox 25 27 29 25 24 26 0.18% 

Swift Fox 7 16 19 8 2 1 14 0.10% 

Feral Hog 5 7 4 7 9 6.40 0.05% 

Bobcat 4 1 5 15 1 5.20 0.04% 

Common Raven 1 1 7 1 2 2.40 0.02% 

Black Bear 3 1 0 4 2 2.00 0.01 % 

Ringtail 0 4 1 2 1 1.60 0.01 % 

Badger 0 4 3 0 0 1.40 0.01 % 

American Crow 0 0 0 4 1 1 .OO 0.01 % 

Gray wolf 2 1 0 0 1 0.80 0.01 % 

Javelina 0 2 0 2 0 0.80 0.01 % 

Woodchuck 1 0 1 0 0 0.40 ~0.01% 

Bald Eagle 0 1 0 1 0 0.40 ~0.01% 

Feral cat 1 0 0 0 0 0.20 ~0.01% 

Chihuahuan raven 0 0 0 1 0 0.20 ~0.01% 

Subtotal 828 925 81 4 658 677 780 5.49% / Total 16,520 14,758 12,949 12,827 14,018 14,214 100.00% 1 

Source: USDA, 2008b 

d Hunting 

Unless prohibited by state laws, both ground and aerial hunting are common methods used to 

take coyotes. For ground hunting, two common ways for locating coyotes are by aircraft or with 

scent tracking dogs. Aircraft are commonly used to locate predator dens, while scent tracking 

dogs can be used to track predators andlor their dens. Aerial hunting, whether done in a fixedwing aircraft or by helicopter, can be hazardous and requires a great deal of skill and must be 

done by professionals. Despite these risks, it is by far the most popular predator control method. 

In 1994, for instance, the Texas Animal Damage Control Service reported owning two fixedwing aircrafts and one helicopter for coyote control purposes. 

Although in most states the coyote is an unprotected species and can be hunted throughout the 

year, hunting may not be suitable or even legal in all situations. For instance, safety concerns 

may preclude the discharge of fire arms near human habitations or where people could be 
present. Shooting may also be prohibited by local laws or target predators may move into a 

neighbor's property and out of the hunter's reach. Aerial hunting is only permitted in some 

states and, although costly, it is generally a cost-effective predator control method. Aerial 

hunting does require special skills for both pilot and shooter. Shooting from fixed-wing aircraft 

works best in open areas with little plant cover, whereas helicopters are more suitable for hunting 

over rugged terrain and areas that support dense vegetation (Green et al., 2005). Although 

shooting invariably results in the death of one or more coyotes, this approach does not readily 

discriminate between sheep predators and nonpredators. 

A 1999 study by Wagner and Conover found that the benefits of aerial hunting outweighed the 

costs. The average cost of aerial hunting in Utah, including helicopter rental, pilot and Wildlife 

Service (WS) hunter wages, ammunition and incidentals, was estimated to be $425/hour. On 

average, it took 2.1 hours to cover a field, indicating that the total cost of aerial hunting was $893 

per field. This translates into a cost of $1 85/coyote, with an average of 2.3 coyotes being 

removed per hour. This is inexpensive in comparison to other corrective control predation 

methods, which on average cost nearly $805/coyote. The benefits come from two sources. First, 

lamb predation was reduced by nearly 18 lambs compared to areas where no aerial hunting 

occurred. With the average price for a lamb in Utah being nearly $76, this results in overall 

savings of around $1,328 from avoided lamb predation. Second, if this predation were to occur, 

it would require about 20 hours of corrective control predation management (that is, using lethal 

methods, such as M-44s, snares, and traps to reduce further predation), which costs about $537. 

Therefore, the total benefits of aerial hunting are calculated by the authors to be $1,865 

($537+$1,328), which outweigh the costs ($893) at a 2:l ratio. BEAD notes, however, that there 

is some double counting of benefits in this study as the expenditure on alternative predator 

control would presumably result in a reduction in lambs lost. 

e. Denning 

Coyotes mate during the winter and their pups are born in the spring. The young usually stay 

with their parents through mid-fall before dispersing and developing territories of their own. A 

technique known as "denning" is a predation control strategy that employs firearms, sodium 

nitrate cartridges for gassing dens, and snares to eliminate entire coyote family units. This 

technique is time-consuming, requires a great deal of tracking and stalking skills, and can be 

employed to remove only confirmed livestock predators. 

Denning involves tracking offending coyotes back to their dens, which are often difficult to 

locate. Denning may entail killing both the parents and the pups, which results in a 98.2% 

decrease in predation incidents and a 98.9% decline in the number of sheep killed (Till and 

Knowlton, 1983). Alternatively, only removing the pups results in an 87.7% decrease in 

predation incidents and a 91.6% decline in the number of sheep killed. This difference is likely 

due to the parents continuing to prey on sheep for their own sustenance, but not for their pups 

(Till and Knowlton, 1983). 

Denning is practiced from about April 15 to July 1 and may be more cost-effective in 

comparison to methods that are implemented year round, such as penning. In 1980, the average 

USDA salary for a worker in Wyoming was $1020 per month, plus $650 in monthly expenses 
($2,68 1 and $1,709 in 2008 dollars, respectively). Denning usually takes place for two 

consecutive years. If this were the case, it would imply that expenses would total $8,350 

($21,952 in 2008 dollars) for each worker. If each worker were to locate, on average, 40 dens 

over the two year period, the average cost for removing each den would be $209 ($549 in 2008 

dollars). Given these assumptions, it would only take five days of denning for the benefits to 

exceed the costs from coyote extermination (Till and Knowlton, 1983). It should be noted that 

the success rate and the benefits of denning may vary considerably given the difficulties of 

tracking coyotes to their den. The costs may also be understated as there may be opportunity 

costs of assigning workers to denning rather than other activities and it is difficult, therefore, to 

make comparisons of cost-effectiveness with other control methods. 

J: Trapping 

Traps and snares are used to take large numbers of coyotes each year. While trapping alone is not 

lethal, successful trapping always leads to the death of captured coyotes, usually by shooting it in 

the head with a .22 caliber gun. Steel-jawed traps and snares are commonly used to capture 

coyotes inhabiting areas where sheep graze. Traps and snares are often placed near kills along 

paths that coyotes are known to follow as they approach pens or pastures for livestock. The use 

of traps and snares requires a great deal of skill and expertise related to coyote behavior, as well 

as an intimate knowledge of the grounds to be protected. Coyotes learn quickly, and traps that 

are not set correctly or that are poorly located will actually teach coyotes how to avoid them. 

Although coyote lures and scents are commercially available and are often used to attract 

coyotes, traps and snares are non-specific and will also serve to capture domestic dogs and other 

non-target mammals, including small livestock. 

Guthrey and Beason (1978) found neck snares to be ten times more selective than traps in terms 

of capturing target species. Studies differ in their reports of the number of coyotes that are 

caught using snares, with 20.3 coyotes/1,000 trap nights being caught in Zavala, Texas, versus 

5.4 coyotes/1,000 trap nights in Canada. This variation is likely a function of coyote density, 

temperature, and weather conditions (Guthrey and Beasom, 1978; Pruss et al., 2002). 

Just as efficacy can vary according to local conditions, costs can vary according to usage. Traps 

and snares may be relatively inexpensive; however, the time involved is likely the more critical 

component. The level of effort expended can range widely. Traps and snares can be set and 

checked frequently or only at one's own convenience. Since traps and snares can be triggered by 

animals other than coyotes, more frequent checks can increase the likelihood of successfully 

removing a problem animal and decrease the likelihood of taking a non-target animal. 

Diazepam is a tranquilizer that has been used to prevent injury to carnivores caught in traps. If 

diazepam tabs are used on a modified neck snare, it decreases the injuries and stress that 

captured animals incur. This is a valuable trait for a predator removal method to have, since it 

implies there will be a low kill rate on non-target animals (e.g., grey wolves). Pruss et al. (2002) 

found that 5.5% of captures in neck snares were nontarget species, which is somewhat higher 

than that for M-44s, which averages about 4.7% (USDA, 2008b). The use of diazepam reduced 

mortality of coyotes trapped with neck snares to less than 2%, suggesting a similar reduction in 
the mortality of non-target species. However, snares had to be checked every 12-24 hours, 

which significantly increases the labor and management cost or use. 

Like neck snares, steel traps can be quite useful in removing coyotes while ensuring the well 

being of nontarget animals if used in conjunction with a tranquilizer. Diazepam tabs are the first 

tranquilizer of choice, however obtaining this in bulk has historically been difficult. This led to 

the use of propiopromazine HCI and clordiazepoxide mixtures. By using a tranquilizer, 7 1% of 

trapped coyotes sustained little or no foot damage, which is significantly less than the 43% that 

are hurt when no traquilizers are used. In 1980, the price of propiopromazine tabs was 20 cents 

(53 cents in 2008 dollars) (Linhart et al., 198 1 cited in Connoly, 1981). For the tranquilizer to 

effectively reduce non-target kills, however, traps must be checked frequently, which can 

significantly increase costs. 

Traps and Snares vs. M-44s 

Studies vary in terms of whether or not steel traps and neck snares are more effective than M44s. In Texas, Guthrey and Beasom (1 978) found that steel traps are more effective over time on 

a catch-per-unit basis than M-44s; however, Beasom (1974) found that M-44s were more 

effective4. This variance may be a function of time, with Beasom's (1 974) study was conducted 

over a 7 month period, while Guthrey and Beasom's (1 978) study was only half that duration. 

As noted by Guthrey and Beasom (1978), this temporal deviation may be related to predator 

removal persistently happening in the same area. It may also be related to the fact that M-44s are 

more efficient at catching coyotes than any other species, while steel traps are indiscriminate and 

catch more non-target species, thus reducing the chances that a coyote is caught in the first place 

(Beasom, 1974). Regarding neck snares, Guthrey and Beasom (1 978) found that they likely are 

less effective than steel traps, but more effective than M-44s. However, since neck snares are 

easy to set up and operate, they can be set out at higher rates and require less labor hours than M44s and steel traps, and can therefore yield higher coyote catch rates than the other two 

alternatives. 

2. Non-lethal Predator Control Techniques 

a Guarding Animals 

Animals commonly used for livestock protection include llamas, donkeys, and several large dog 

breeds of European and Asian origin. While guard dogs have been used for sheep protection in 

Europe and Asia for centuries, this practice was not adopted by ranchers in the United States 

until the mid 1970s. Guard dogs are selected for their ability to bond with sheep, especially 

when pups are raised along with lambs. Unlike herding dogs, guarding dogs are not trained to 

respond to voice commands and provide protection against predators simply by being with the 

flock at all times; they alert sheep to the presence of potential predators and actively chase them 

away if they approach them. Employing guard dogs is incompatible with the use of M-44 

devices, traps, and snares, unless the dogs are trained to avoid them. Llamas and donkeys are 

also used as guarding animals as they naturally defend flocks of sheep with which they are 

placed. Their large size and aggressive behavior may deter coyotes from attacking or even 

4 These efficacy measures are based on the capture rate, which is the number of captures/1,000 device days. 

2 5 
approaching sheep, although coyotes may still be able to attack under the cover of darkness or in 

rough terrain. Llamas may not be able to distinguish between coyotes and domestic dogs and 

have been known to attack herding dogs (Tirnrn and Connolly, 2001). The same is true of other 

guard animals. The usefulness of guarding animals is enhanced when used in conjunction with 

other predator and husbandry management practices. 

In 1999,28% of sheep producers used guard dogs in the United States, while 13% and 9% used 

guard llamas and donkeys, respectively (NASS, 2000 cited in Andelt, 2004). The number of 

guard dogs increased to 32% in 2004; however, there was no substantial change in use of guard 

llamas and donkeys (USDA NASS, 2005). Table 13 presents information on the use of guard 

animals. According to another recent survey, almost one-fifth of 1 1,000 Texas ranchers reported 

having used donkeys as small livestock guard animals (Green et al., 2005). The efficacy of these 

methods varies with the type of guard animal used and also with respect to individual animals; 

some simply lack the drive to defend sheep against coyote attacks. Studies have found that 

sheep producers in Colorado who did not use guard dogs lost approximately two to six times as 

many lambs to predators over an eight year period of time (Andelt and Hopper, 2003 cited in 

Andelt, 2004). A study in North Dakota reported that sheep producers experienced a 93% 

reduction in sheep predation losses after obtaining a guard dog (Pfeifer and Goos, 1982). Guard 

llamas have also been found to be effective, with the average number of ewes and lambs killed 

by coyotes reduced from 2 1 % to 7% (Franklin and Powell cited in Andelt, 2004)'. 

Table 13: Percent of Sheep Operations Using Guard Animals to Prevent Predator Losses, 

2004. 

Source: USDA NASS, 2005 

1 Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. 

Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

The use of guard animals is the most common means of non-lethal predator control in cattle 

production, with 38% of cattle operations indicating that they employ guard animals (USDA, 

2006). 

To date, the efficacy of guard donkeys has not been researched in peer-reviewed publications. 

2 6 
Cost of Guard Animals 

Regarding the costs and benefits of these guard animals, pups cost around $150 to $500, adults 

cost $300 to $1,000, and maintenance costs are around $250 annually. The cost of a guard dog is 

usually dependent on a number of factors, such as breed, age, and temperament (Andelt, 2004b). 

The benefit of guard dogs in terms of avoiding sheep loss has been reported to be between 

$2,506 and $3,733 annually ($5,225 and $7,783 in 2008 dollars) (Green et al., 1984; Andelt and 

Hopper, 2000 cited in Andelt, 2004). Guard llamas tend to cost between $450 and $800 ($674 

and 1,119 in 2008 dollars), with annual expenses averaging $105 ($157 in 2008 dollars). Again, 

in terms of the reduction in the number of livestock lost to predation, the annual benefit of a 

guard llama has been estimated to be $1,253 ($1,878 in 2008 dollars) (Franklin and Powell, 1993 

cited in Andelt, 2004). Guard donkeys cost between $144 and $236 ($252 and $314 in 2008 

dollars), with annual expenses averaging $66 ($1 15 in 2008 dollars) (Franklin and Powell, 1993 

cited in Walton and Field, 1989; Bergrnan et al., 1998, cited in Walton and Field, 1989). 

The age of guard animals must also be considered when assessing the benefits they can provide. 

Dogs live 10- 12 years, and can be ready to guard livestock at around eight months of age. 

However, dogs run the risk of death early on in their lives due to accidents. Llamas live for 10- 

15 years, with the average guard llama being two years old; however, the age of llamas has been 

found to vary from less than one year old to 12 years, making a conservative estimate of their 

useful life as a guard animal around 1 1 years. Donkeys are useful for 10-1 5 years, which is the 

longest useful life of any guard animal (Wilbanks, 1995). 

Guard animals vary in terms of their suitability for certain herd sizes. Guard dogs are most 

effective for herds of sheep that are 200 head or less (or 200 acre fields). Llamas are more adept 

at watching herds of 250-300 sheep (or 250-300 acres). Unlike guard dogs, which can be 

grouped together to watch sheep (1,000+ in some instances), multiple guard llamas have not 

been found to be more effective than a single llama (Franklin and Powell, 1993 cited in Andelt, 

2004)~ The use of llamas and donkeys is also somewhat lower in the Pacific states and West 

Virginia (areas with relatively high predation), and may be due to the generally smaller herd 

sizes in these states. A large guard animal for a flock of 30 to 40 sheep may simply not be cost 

effective. Finally, guard llamas and donkeys are not a threat to non-target species, but there have 

been cases in which guard dogs have paired with wolves to prey on livestock (Andelt, 2004) or 

have preyed on wildlife (Larson, 2006). 

An examination of Table 13 suggests that the use of guard dogs is fairly consistent throughout 

the United States, although BEAD views these numbers with caution. Without more information 

about the survey, it is not clear that guard dogs represent the types and uses discussed here. We 

also note that the use of llamas decreases as one moves south, where donkeys appear more 

favored. Llamas are Andean animals that are best suited to high elevations and cooler 

temperatures similar to those found in the Mountain West and Northern Plains while donkeys 

thrive in the hot and arid desert regions of the southwestern deserts,. Llamas are not adapted to 

hot and dry conditions and are susceptible to heat stress during the summer months; these 

conditions could lead to poor growth, illness, or even to the death of the animals. Recommended 

-- - 

6 Limited coverage data was available on guard donkeys. 

2 7 
protection measures include shearing and providing abundant fresh water and shade, and even 

artificial ventilation. Such requirements may not make llamas a cost effective method for 

predator control, especially when considering that their performance and ability to function as a 

guarding animals may falter when subject to such stress (Free and Anderson, 2003). 

b. l4giIance (Herding) 

The presence of a herder alone may discourage predators from initiating an attack. Skilled and 

alert herders can further discourage predation by rapidly taking protective measures if a predator 

approaches the flock. The employment of herders seems to have declined in recent years 

because of increasing costs and shortages of well-trained personnel (Green et al., 2005). 

According to USDA statistics, 6.6% of sheep operations employed herders to prevent predator 

losses in 1999 (USDA NASS, 2000), and 5.7% of opkations did so in 2004 (USDA NASS, 

2005). Herders' services are cost-prohibitive to some ranchers (Shivik, 2003), and may be one 

reason that only nine percent of sheep and goat producers used herders in 1984 (Nass and 

Theade, 1984). Table 14 presents the percentage of operations using herding and frequent 

checks by state in 2004. 

It has been shown that herding leads to consistently smaller rates of lambkid predation relative 

to other, more common practices, such as fencing, shed lambing, and daily sheep checks. 

Specifically, in a study where the average rate of lambkid predation was greater than 5%, 89% 

of producers reduced predation to less than 5% using a herder (Nass and Theade, 1984). It has 

also been suggested that one of the most effective and cheapest ways to target problem coyotes is 

to equip a herder with a flat-shooting, scoped rifle. Since coyotes that are seen near a flock are 

ones that tend to kill sheep, herding c& be considered a selective form of lethal control 

(McAdoo and Glimp, 2000). 

The cost of herding is a clear deterrent to its use. However, as the percentage of operations using 

herding as a means to prevent predator losses is low throughout the United States, certain areas 

that experience exceptionally high rates of predation, such as Arizona, California, West Virginia, 

and the Mountain West, on average rely more heavily on herding. 
Table 14: Percent of Sheep Operations Using Herding, Frequent Checks, and Fencing to 

Prevent Predator Losses, 2004. 

I Northern plains ' 4.4 15.2 19.9 2.5 

State 

Arizona 

California 

Mountain West ' 

Herding 

11.6 

10.0 

10.4 

Texas 

Plains 

Pacific 

East 

Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. 

5 Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

Frequent Checks 

27.1 

11.8 

20.6 

5.2 

3.2 

West Virginia 

United States 

Herding is less used in cattle production, with 3.8% of cattle operations indicating that they use 

herders to prevent predator losses (USDA, 2006). More cattle operations, 21.8% conduct 

frequent checks, however, as a preventative measure. 

3.9 

5.9 

c. Exclusion (Fencing) 

Fencing 

40.1 

71.9 

45.2 

16.7 

5.4 

Source: USDA NASS. 2005 

14.2 

5.7 

Using fences to exclude predators can be an effective sheep protection technique. However, to 

be effective, the fences must be virtually coyote proof. That is, they must not allow coyotes to 

go over, under, or through them at any time. Fences must be at least 5.5 ft tall to keep coyotes 

from jumping over them. An overhang on the outside of the fence would discourage climbing. 

To prevent coyotes from digging under them, fences can be outfitted with aprons that extend one 

foot into the ground. They should be inspected regularly in order to rapidly repair damaged 

sections or trim away vegetation that may be growing too close, as it can be used by coyotes to 

bridge the fence. Portable fences are available for containing small flocks, and can also be 

electrified for additional protection. A major drawback of fencing as a sheep protection 

technique is its high maintenance cost. Fences work best for small operations and may be costprohibitive to construct and maintain. They may also be impractical when pastures or rangelands 

are extensive, when terrain is highly irregular, or when there is an abundance of vegetation. As 

for other predation management options, fencing works best when used with other management 

techniques. 

Deterrents 

2.4 

5.9 

5.0 

22.1 

14.4 

In a survey by Nass and Theade (1988), woven wire fences are a popular method for reducing 

lambkid predation, with 100% of 95 surveyed producers in California, North Dakota, Oregon, 

and Texas using wire fences. However, it does not appear that this method is particularly 

effective, with 45% of producers reporting lambkid predation being greater than 5%. Table 14 

32.0 

46.1 

65.1 

14.0 

0.8 

1.3 

58.7 

5 1.4 

2.2 

2.4 

67.3 

52.5 

1.3 

2.2 
presents data from USDA on sheep operations using fencing. Much lower numbers are shown in 

Table 14 than in the Nass and Theade (1988) survey. A difficulty in interpreting any of these 

results is that it may be difficult to determine whether an operation identifies a practice 

specifically for predator control or whether the practice is part of the total production system. 

In an interview of over 100 sheep producers in the Pacific Northwest by Nass and Theade 

(1 988), electric fencing is shown to be a relatively successful method among these producers in 

reducing sheep predation, with a 91.4% decrease in the loss of sheep due to predation, from an 

average of 41 head lost per flock per year to an average of 3.5 annually. Overall, 45% of sheep 

producers interviewed in this study who had experienced sheep predation incurred none after 

installing fences. The study points out that although fences last an average of 20 years with 

proper maintenance, they are quite expensive to install. In 1983 prices, they cost $554 per mile 

of fence in this region ($1,204 in 2008 dollars). With a mean coverage of 301 acres for an 

average flock size of 1,036 head, this indicates that the average cost to install fences for a sheep 

producer would be $4,170 ($9,069 in 2008 dollars) which may not be feasible for many 

producers in the Pacific Northwest. Fencing is likely to be infeasible for other regions of the 

United States, such as Texas, where sheep production tends to occur on the open range, making 

fencing impossible. Other limitations, such as topography and flock size, can also influence the 

effectiveness of fencing. Issues such as these, along with other factors such as the life of the 

fence, its cost, the level of predation control desired, and the predation level being faced are all 

things a producer should reflect upon when considering whether or not fencing would be a costeffective predation control option for them (O'Brien, 2002). 

The installation and maintenance of coyote-proof, net-wire fences is generally expensive and 

rarely used, except around confined spaces where there is a high stocking density (e.g. pens, 

corrals and feedlots). Although the use of fences does reduce predation, total exclusion of 

coyotes through fencing is unlikely, as some coyotes eventually learn how to breach fences by 

digging under or by climbing over. Fencing is impractical where the area to be protected is 

extensive and the stocking density is low, such as in western range sheep operations (Wilbanks, 

1995). 

Fencing for predator protection is used by 34% of cattle operations (USDA, 2006). Fencing is 

probably more feasible in concentrated dairy production than in extensive grazing operations for 

beef cattle. 

One of the major drawbacks to fencing is that it acts as a physical barrier to many species and 

can result in habitat fragmentation. In addition to short-term risks associated with habitat 

fragmentation, such as food shortages, it can significantly reduce species and genetic diversity, 

which is of utmost concern regarding the vitality of threatened and endangered species (Groom 

et al., 2005). 
d Deterrents 

Sound and light producing devices can be used to deter predators, especially at night, when most 

predation occurs. One such device is the propane exploder or "gas cannon". This device uses a 

spark to ignite a charge of propane or acetylene into a firing chamber, producing a loud 

explosion that resembles the firing of a 12-gauge shotgun. Timers attached to the device are 

used to trigger random or intermittent explosions. A photo cell can be included to turn the 

system on at night. Changing its location every few days increases its effectiveness as a predator 

deterrent. 

There are several battery-operated devices that create sound to deter coyote predation on 

livestock. For example, some emit the sound of barking hounds to scare away coyote. The most 

popular frightening device is the "Electronic Guard", which was developed by APHIS WS. This 

battery-operated device is available from the Pocatello Supply Depot and emits sound (sirens) 

and strobe lights, randomly or at regular intervals. It is activated at night by means of a 

photoelectric cell or by motion sensors in the area. Linhart et al. (1 992) analyzed the 

effectiveness of this frightening device in deterring coyote predation in Western Colorado. The 

study found that, on average, sheep losses to coyote predation in mountainous areas were 

reduced by 60% during the summer at a savings of $2,400 per flock using 1983 and 1984 market 

prices (6.6% of total lambs lost prior, 2.7% after the fightening devices were deployed). Tests 

conducted by the National Wildlife Research Center (NWRC) indicate that sheep predation can 

be reduced by an average of 80 percent in range and field scenarios, and 60 percent in the 

mountains, supporting the findings of Lindhart et al. (1992) (APHIS fact sheet, 2002). The 

Electronic Guard costs approximately $250. 

Although effective, the Electronic Guard is not intended for year round use since coyotes 

become conditioned to it and eventually ignore it. However, limiting its use to only the lambing 

season can significantly reduce the number of lambs killed by coyotes. APHIS WS recommends 

that at least two guards be used for small, enclosed pastures (20-30 acres), while three to four 

should be used for larger, enclosed pastures (3 1-1 00 acres). Four or more should be used if a 

band has more than 1,000 head of ewes and their lambs. 

One common problem with any type of deterrent is that coyotes will eventually habituate to the 

stimulus in periods that may range from a weeks to months. As for other types of pest problems, 

excessive reliance on any one type of pest management technique deterrents will only provide 

limited or temporary protection in the long run. Another drawback inherent to these devices is 

that the loud sounds produced can be disturbing to neighbors and other wildlife in the area. 

Deterrents, which generally have fixed locations, will also not work well with large flocks on 

extensive rangeland. The relatively high use of deterrents in the Mountain West (Table 14) 

would seem to refute this hypothesis, but the average for the region is skewed by heavy use in 

New Mexico. 

Deterrents are also rarely used in cattle production, but as in sheep production, is common in 

Idaho and New Mexico, where respectively 20.6% and 25.5% of operations report using such 

tactics (USDA, 2006). 
e. Husbandry management practices 

Producers may also rely on a variety of husbandry management practices to minimize livestock 

exposure to predation, including: 

i. Avoiding high predation areas 

Coyote depredation may be greater in certain areas due to factors such as an abundance of 

vegetation or terrain characteristics that facilitate stalking and approaching prey. Identifjmg and 

avoiding those areas may result in fewer livestock lost. However, this approach may not always 

be practical because it may interfere with pasture utilization and other management practices. 

ii. Night penning 

Since most coyote attacks occur at night, herding sheep back into enclosures nightly is another 

technique that reduces the risk of predation. Keeping a light on over such enclosures further 

discourages potential predators from approaching. As for most of the other management 

practices discussed here, night penning by itself does not provide full protection from predators. 

Rather, it is the adoption of several complementary management practices that have the greatest 

likelihood of minimizing predation. 

Night penning, like herding, is used less often than methods such as fencing, shed lambing, and 

daily checks. Although no definitive studies were found in this review, it has been suggested that 

this method is much more effective than such alternatives. Nass et al. (1 984) found that although 

only 12% of surveyed producers penned at night, 73% of them began to experience less than a 

5% rate of livestock predation. In 2004, nearly one-third of producers indicated that they utilized 

night penning (USDA NASS, 2005). See Table 15. For large flocks and extensive grazing, 

night penning may only be practical for short periods during the lambing season. 

Night penning may also be impractical for cattle operations, except for dairy cattle, because most 

depend on extensive grazing. Pens or corrals for cattle would also entail higher costs than for 

sheep. USDA (2006) reports less than 10% of cattle operations practice night penning to prevent 

predator losses. 

iii. Shed lambing 

Since coyotes that prey on sheep generally target lambs, keeping ewes that are about to give birth 

in protected enclosures would reduce the risk of predation. Because of logistics and labor costs, 

this practice may be more suitable for smaller flocks. 

This method is highly effective, and can result in lamb rates of 150% to 200%, compared to 60% 

to 130% on the range.7 The benefits of shed lambing extend beyond reducing predation. It can 

reduce the loss of lambs to risks such as disease and poor weather conditions and can also 

increase the weight of a weaned lamb by 20% in comparison to pasture or range lambing. 

Despite these benefits, shed lambing remains difficult to implement given its extraordinarily high 

costs. If predation is the only concern, studies suggest that shed lambing is only cost effective if 

7 This is accounting for twins. 
more than 20% of lambs are lost to predation (Walker et al., 1993; Burfening and Van Horn, 

1993; McAdoo and Glimp, 2000). 

Table 15: Percent of Sheep Operations Using Husbandry Management Practices to Prevent 

Predator Losses. 2004. 

State 

Arizona 

California 

Night Penning 

Mountain West ' 

Northern Plains 

27.8 

35.6 

Texas 

Plains 

Shed Lambing 

41.9 

38.0 

pacific 

East 

I - I - 1 - I 

Source: USDA NASS, 2005 

Sanitation 

32.2 

33.8 

23.7 

41.5 

West Virginia 

United States 

Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. 

North Dakota and South Dakota. 

Kansas, Nebraska, and Oklahoma. 

4 Oregon and Washington. 

Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, North 

Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. 

4.2 

12.5 

39.9 

30.7 

38.7 

30.0 

iv. Sanitation (carcass removal) 

22.6 

12.1 

16.3 

30.1 

12.0 

32.9 

Sanitation is the removal of dead livestock to avoid attracting predators to the area. This 

technique is more suitable to smaller operations, and is less practical for larger operations with 

extensive pasture. However, 16.5% of cattle operations practice sanitation and 19.6% of 

operations report culling their herds of old, sick, or otherwise weak animals (USDA, 2006). 

4.7 

6.5 

43.7 

3 1.6 

v. Monitoring sheep numbers (record keeping) 

25.1 

9.8 

22.8 

30.8 

Maintaining a strict control of sheep numbers in order to rapidly note if sheep are missing is 

another management technique that provides an early warning of predator activity, thus allowing 

ranchers to take appropriate protection actions before too many sheep are lost. It is not, 

however, a protective measure. 

10.6 

11.7 

vi. Altering breeding times fall lambing) 

The risk of coyote predation on lambs tends to increase during the spring and summer, when 

coyotes whelp and rear their pups. Although spring lambing coincides with the natural breeding 

and lambing seasons, this is also the season when risk of coyote predation is highest for lambs. 

Spring lambs are born to ewes bred during September through November, but for ewes to lamb 

in the fall, they must be bred in May and June. Most lambs born in the fall are larger and less 

vulnerable to predation during the peak coyote predation period. A major drawback of this 

technique is that the natural estrus cycle of ewes must be artificially altered. Another limitation 
is that fall lambing may be not be compatible with marketing concerns or range and weather 

conditions. 

J Experimental Techniques 

Various repellents have been evaluated in the past with limited success. Treating sheep collars 

with chemical repellents, such as capsaicin, has not been found to effectively deter predation, 

since after its first exposure, coyotes tend to avoid the neck region and attack unprotected parts 

of sheep, such as the hind-quarters. Plastic collars designed to protect the neck region of sheep 

from attacks from jackals have been tested in South Africa. Even training collars have been 

tested to teach coyotes not to attack sheep (Shivik, 2003). Although a detailed review is not 

provided here, Andelt et al. (1 999) reviewed the training collar method, and found that over a 22 

week period, the collars averted all 13 attempted attacks on lambs by nine coyotes (all of which 

were noted for previous lamb killings). However, it is not likely that many livestock producers 

will spend the effort to capture a coyote in order to collar and release it. 

V. Discussion and Conclusions 

Conflicts between the livestock industry and mammalian carnivores, especially coyotes, are 

often unavoidable as livestock and potential predators frequently occupy the same territory. 

Predation problems seem to be highly variable and localized, and can be rare or absent in some 

operations and moderate to severe in others. 

The petitioners allege that the benefits of M-44 and LPCs are low, in part, because other means 

of predator control, particularly non-lethal means, are effective. The petition cites a recent 

newspaper article describing the success of a program in Marin County, California, as evidence 

that eliminating the use of M-44 and LPCs would not result in substantial impacts to livestock 

producers (Brenner, 2005). The article claims that the county initiated a completely non-lethal 

program consisting of guard animals, electric fencing, deterrent devices, and other practices. 

The county agricultural commission is quoted as reporting a decline in predator losses from 5% 

of stock to 2.2%. Brenner (2005) and Fox (2006) indicate that the Marin County program 

replaced the use of M-44 and 1080. However, use of these measures, along with certain traps, 

had been banned in 1998 by a state-wide referendum. Fox (2006) also reports that, while the 

Marin County program ended funding for federal trapping assistance, ranchers can use lethal 

measures, including hunting and trapping, on their own lands. 

Larson (2006) disputes some of the claims made about the program. While losses were low the 

initial year of the program, they appear to have returned to levels observed in previous years. 

Losses on individual ranches have been over 18% in some years. Moreover, reported losses only 

include participating ranches, which number about 18 out of 29 in the county (Brenner, 2005). 

Larson also presents anecdotal evidence that the number of coyotes taken may have increased as 

individual producers continue to employ lethal measures. Finally, Larson shows that costs to the 

county have increased under the new program, in part because the county compensates ranchers 

for lost sheep at their market value. 
It is unlikely that a program such as that in Marin County, even assuming it is as effective as 

proponents say, could be extended to other areas. Timm and Connolly (2001) report that the 

LPC was the most effective means of protecting sheep at the Hopland Research and Extension 

Center in Mendocino County, just north of Marin. They report problems with guard animals in 

terms of effectiveness, in part because of rugged terrain and large pastures. They also report a 

decline in wild turkeys associated with the use of guard dogs and several deer killed by the dogs. 

Woven-wire fencing with a ground-level electrified wire proved ineffective. High-tensile 

electric fencing reduced predation but proved costly to maintain (Timm and Connolly, 2001). 

BEAD concludes that a concerted program of non-lethal measures can be effective with smaller 

flocks and small pastures of relatively even terrain. However, this does not correspond to much 

of the Mountain West and Texas, where large flocks and extensive grazing are practiced. 

Comments submitted to the Agency suggest that many producers rely on a mix of predator 

management techniques, both lethal and nonlethal, to protect livestock from predation by coyotes 

and dogs. The use of any combination of predator control techniques is sometimes described in 

the literature as integrated predator management ("IPM"). For instance, in discussing the role of 

guarding animals, Wilbanks (1995) states that donkeys are "... compatible with most traditional 

methods of predator control and can be used in an integrated predator management program." 

Similarly, according to Franklin and Powell (1 994), the best protection to livestock is 

accomplished through an IPM program that includes both preventive (i.e., nonlethal methods) 

and selected control methods, since no single method is fully effective by itself. 

One example of IPM working can be seen in West Virginia. The coyote population has been 

increasing during the past several years in the southern and southwestern regions of this state due 

to the extinction of the eastern wolf and the re-establishment of deer herds (West Virginia DNR). 

In West Virginia, sheep often graze on semi-isolated mountain pastures without human or animal 

guardians (Houben, 2004), and are likely at risk of predation. In the 1990s, USDAIAPHIS 

Wildlife Services implemented predator management programs in West Virginia using both 

nonlethal and lethal techniques, which included the use of LPCs. From 2000 to 2002, 

approximately 12% of sheep producers participated in the program, with seemingly positive 

results in terms of reducing sheep and lamb lost to predation. However, it cannot be assumed 

that such success can be achieved for all producers for reasons such as variations in topography 

and predation rates; therefore, lethal methods, including the use of M-44s and 1080s, will likely 

need to be incorporated into many producers IPM programs in order for them to obtain 

reductions in livestock predation. 

Comments submitted to the Agency indicate that while some livestock producers do not use M44 devices or LPCs, others consider them to be essential to the viability of their operations. A 

number of producers affirm that these tools are used only as an option of last resort to be used 

when all other predator control attempts have failed. Others consider them essential components 

of their overall predator management programs. Because the intensity of predation on sheep, 

goats, and cattle depends on factors such as terrain, vegetation, pasture location and size, 

flockJherd size, predator abundance, prevalence of the predator's natural prey, choice of prey 

control measures, and the unique characteristics of each livestock operation, producers' 

experiences with predation would be expected to vary significantly. Furthermore, considering 

the many factors that can affect predation, it is unlikely that any one combination of predator 
management techniques will work equally well in all situations. Thus, when or where predation 

is severe, producers may rely more on lethal methods than in situations where the predator 

pressure is relatively low. When non-lethal control measures fail to prevent sheep losses, 

producers inevitably turn to lethal methods, and many have found the M-44 device to be 

effective and convenient, especially when aerial hunting is impractical due to heavy plant cover 

or when freezing conditions preclude the use of traps and snares. 

While the M-44 ejector is designed to attract canids, especially coyotes, it cannot discriminate 

between coyotes that prey on sheep and those that do not. However, with the exception of 

denning and hunting, alternative lethal control methods (hunting, trapping, snaring) are not 

necessarily any more selective than M-44s in terms of taking non-target species. Hunters, 

including those practicing denning, may rarely kill other species, but they likely kill coyotes that 

are not preying on sheep. LPC's are the most selective means, as they kill only the attacking 

animal. 

Overall, it is evident that M-44 and LPC devices provide benefits to livestock producers, 

particular producers of sheep and goats but also of cattle, and if users had to rely on the available 

alternatives, they would likely incur higher costs and more predation. In light of the competitive 

nature of the industry, such a change could force producers out of business. 

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