The Greatest Map on Earth

By Nancy Bazilchuk

People have been killing predators to protect livestock for thousands of years, and today many countries around the world have government programs to control predators. But any benefits to the livestock industry are assumed rather than proven. New research raises questions about this assumption by showing that U.S. coyote control programs do little—if anything—for the sheep industry that they supposedly boost.

Although coyotes are hardly threatened, this predator control program still has a major conservation downside. “Taxpayer-subsidized control programs help perpetuate the public perception of carnivores as widespread livestock killers,” says Kim Murray Berger of the Wildlife Conservation Society in Conservation Biology. “[This] may hinder conservation of threatened species through direct persecution or resistance to reintroduction efforts.” Furthermore, predator control programs have threatened other species, including African wild dogs and gray and red wolves.

The U.S. sheep industry has declined by more than 85 percent since peaking in 1942, and coyotes are widely blamed. They are the primary targets of federally subsidized programs to protect sheep from predation and comprise about 95 percent of the large carnivores killed in the last 20 years. During this period, coyotes have been killed at an annual rate of roughly 80,000 and at an annual cost of US$20.

Berger is the first to assess what we are really getting for all that money and effort, not to mention all those coyote deaths. She modeled how the U.S. sheep industry is affected both by predator control and by economic factors, including lamb prices and hay and labor costs. She used the number of sheep as a measure of the industry’s viability and the amount spent on predator control as a measure of that effort.

The results showed that we aren’t getting what we thought by killing coyotes. Rather, predator control has had little impact on the sheep industry, accounting for only six percent of the trends in sheep numbers. This finding is further supported by the fact that sheep trends have been much the same in western and eastern states, even though the latter were colonized by coyotes relatively recently and lack federal predator controls. “Berger’s results are long overdue and should help shape policy in the U.S. and elsewhere,” says Paul Beier of Northern Arizona University in Flagstaff. “It’s amazing that U.S. citizens have supported these programs for decades in the absence of a rigorous assessment.”

So what is actually behind the decline of the sheep industry? Berger’s model implicates economic factors. For example, hay prices rose 44 percent and sheep numbers dropped 44 percent between 1966 and 1976. Moreover, lamb prices dropped by nearly 25 percent whereas real wages more than doubled between 1939 and 1998. “Taxpayer dollars might be better spent to support sheep producers through direct cash payments or some other form of subsidy if the goal is to increase sheep and wool production and not merely to kill carnivores,” says Berger.

About the Author

Nancy Bazilchuk is a freelance science writer based in Norway.

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