Damage and Damage Identification

Coyote, Canis latrans

Coyotes can cause damage to a variety of resources, including livestock, poultry, and crops such as watermelons. They sometimes prey on pets and are a threat to public health and safety when they frequent airport runways and residential areas, and act as carriers of rabies. Usually, the primary concern regarding coyotes is predation on livestock, mainly sheep and lambs. Predation will be the focus of the following discussion.

Since coyotes frequently scavenge on livestock carcasses, the mere presence of coyote tracks or droppings near a carcass is not sufficient evidence that predation has taken place. Other evidence around the site and on the carcass must be carefully examined to aid in determining the cause of death. Signs of a struggle may be evident. These may include scrapes or drag marks on the ground, broken vegetation, or blood in various places around the site. The quantity of sheep or calf remains left after a kill vary widely depending on how recently the kill was made, the size of the animal killed, the weather, and the number and species of predators that fed on the animal.

One key in determining whether a sheep or calf was killed by a predator is the presence or absence of subcutaneous (just under the skin) hemorrhage at the point of attack. Bites to a dead animal will not produce hemorrhage, but bites to a live animal will. If enough of the sheep carcass remains, carefully skin out the neck and head to observe tooth punctures and hemorrhage around the punctures. Talon punctures from large birds of prey will also cause hemorrhage, but the location of these is usually at the top of the head, neck, or back. This procedure becomes less indicative of predation as the age of the carcass increases, or if the remains are scanty or scattered.

Figure 2. Footprints of canid predators

Coyotes, foxes, mountain lions, and bobcats usually feed on a carcass at the flanks or behind the ribs and first consume the liver, heart, lungs, and other viscera. Mountain lions often cover a carcass with debris after feeding on it. Bears generally prefer meat to viscera and often eat the udder from lactating ewes first. Eagles skin out carcasses on larger animals and leave much of the skeleton intact. With smaller animals such as lambs, eagles may bite off and swallow the ribs. Feathers and “whitewash” (droppings) are usually present where an eagle has fed.

Coyotes may kill more than one animal in a single episode, but often will only feed on one of the animals. Coyotes typically attack sheep at the throat, but young or inexperienced coyotes may attack any part of the body. Coyotes usually kill calves by eating into the anus or abdominal area.

Dogs generally do not kill sheep or calves for food and are relatively indiscriminate in how and where they attack. Sometimes, however, it is difficult to differentiate between dog and coyote kills without also looking at other sign, such as size of tracks (Fig. 2) and spacing and size of canine tooth punctures. Coyote tracks tend to be more oval-shaped and compact than those of common dogs. Nail marks are less prominent and the tracks tend to follow a straight line more closely than those of dogs. The average coyote’s stride at a trot is 16 to 18 inches (41 to 46 cm), which is typically longer than that of a dog of similar size and weight. Generally, dogs attack and rip the flanks, hind quarters, and head, and may chew ears. The sheep are sometimes still alive but may be severely wounded.

Accurately determining whether or not predation occurred and, if so, by what species, requires a considerable amount of knowledge and experience. Evidence must be gathered, pieced together, and then evaluated in light of the predators that are in the area, the time of day, the season of the year, and numerous other factors. Sometimes even experts are unable to confirm the cause of death, and it may be necessary to rely on circumstantial information. For more information on this subject, visit ICWDM.org

Legal Status

The status of coyotes varies depending on state and local laws. In some states, including most western states, coyotes are classified as predators and can be taken throughout the year whether or not they are causing damage to livestock. In other states, coyotes may be taken only during specific seasons and often only by specific methods, such as trapping. Night shooting with a spotlight is usually illegal. Some state laws allow only state or federal agents to use certain methods (such as snares) to take coyotes. Some states have a provision for allowing the taking of protected coyotes (usually by special permit) when it has been documented that they are preying on livestock. In some instances producers can apply control methods, and in others, control must be managed by a federal or state agent. Some eastern states consider the coyote a game animal, a furbearer, or a protected species

Federal statutes that pertain to wildlife damage control include the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which deals with using toxicants, and the Airborne Hunting Act, which regulates aerial hunting. Laws regulating coyote control are not necessarily uniform among states or even among counties within a state, and they may change frequently. A 1989 Supreme Court action established that it was not legal to circumvent the laws relative to killing predators, even to protect personal property (livestock) from predation.

Economics of Damage and Control

Sheep numbers in the United States have declined about 80% from 1942 to 1976 (Gee et al. 1977). Former sheep producers reported that the principal reasons for leaving the sheep industry included high predation losses, low lamb and wool prices, a shortage of good hired labor, and the producer’s age.

The US Fish and Wildlife Service (1978) estimated the economic impact of coyote predation on producers with predator problems, on producers with-out predator problems, and on consumers during 1977. They used an average lamb loss rate of 4% (267,000 lambs) and a ewe loss rate of 1.5% (125,000 ewes) to estimate an economic loss of $19 million to producers from coyote predation in the 17 western states. The reduced number of sheep and lambs resulted in a higher market price, which benefited producers by $6 million. The net impact of coyote predation on sheep producers was a loss of $13 million, and the impact on consumers was $4 million in additional costs. The General Accounting Office (GAO 1990) estimated that coyotes in 17 western states killed sheep and lambs valued at $18 million in 1989. The National Agricultural Statistical Service (NASS 1991) reported that sheep and lamb losses to coyotes in the United States were valued at $18.3 million in 1990. The US Fish and Wildlife Service (1978) reported calf losses between birth and weaning to coyotes across the United States at 0.4%, with predation decreasing to nearly zero by weaning time. Dorrance (1982) reported that coyotes were responsible for 16% of the 1,520 confirmed predation losses of cattle in Alberta from 1974 to 1978. Coyote predation on calves caused producers with coyote problems across the United States to lose an estimated $20 million. However, because of the greater price flexibility of beef compared with sheep, the reduction in the number of beef calves marketed (estimated at 0.4%, or 115,000 fewer calves) resulted in a higher price, which benefited beef producers by $81 million. The net impact of the reduced supply of beef as a result of coyote predation was a gain of $61 million to beef producers, but it cost consumers an additional $98 million in higher prices for beef, resulting in an overall loss of $37 million. NASS (1992) reported that cattle and calf losses to coyotes in the United States were valued at $24.3 million in 1991.

Coyote predation also can cause substantial losses of domestic goats. In three studies in Texas, where an estimated 1.1 million goats (about 90% of the goats in the United States) are raised (Scrivner et al. 1985), predators were reported to take 18.1% of the adults and 33.9% of the kids (Pearson 1986). NASS (1991) reported that goat losses to coyotes in the United States were valued at $5.7 million in 1990.

Pearson (1986) stated that predators, particularly coyotes, accounted for losses of hundreds of chickens and turkeys in the 14 western states. In one study, Andelt and Gipson (1979) reported that between June 4 and August 31, 1976, a mated pair of coyotes apparently killed 268 domestic turkeys in Nebraska valued at $938.

Although the average value of livestock losses to coyotes reflected the overall impact on producers, it did not reflect the severity of losses to some individuals. Balser (1964) and Gee et al. (1977) indicated that coyote predation is much more serious for some producers than others. Most sheep producers suffer no or minor predator losses, whereas 20% to 25% of the producers suffer losses that are significantly higher than the average (US Fish Wildlife Service 1978). These losses can drive producers out of business because of low profit margins. Non-fatal injuries and harassment of livestock by coyotes also can result in reduced weight gain and subsequent reductions in profit.