Killing varmints ranks with cowboy hats, rodeos and pickup trucks as an integral part of Western culture. Ranchers, farmers and hunters often blame big predators -- cougars, bears, wolves and coyotes -- for killing livestock and "desirable" big game species.

The agency responsible for doing much of the killing is the taxpayer-funded Wildlife Services, which is part of the federal Animal and Plant Health Inspection Service.

According to a recent "War on Wildlife Report" issued by WildEarth Guardians, the agency spent $427 million to kill 8.4 million animals from 2004-07. The report said that 121,524 carnivores, including 90,000 coyotes, 511 black bears and 340 endangered gray wolves, were killed by Wildlife Services in 2007 alone at a cost of $117 million.

WildEarth Guardians, along with other environmental organizations such as the Utah-based Western Wildlife Conservancy, Utah Environmental Congress, Wild Utah Project and Bear River Watershed Council, have written to the Obama administration and characterized much of what Wildlife Services does as a waste of taxpayer dollars. In its 108-page report, the Guardians charge that the program is biologically unsound, dangerous (the aerial gunning program alone has resulted in 10 deaths in recent years), fiscally unsound, unnecessary and out of step with American values.

The report quotes economist Kim Murray Berger's 2006 study that found 85 percent of U.S. sheep producers went bankrupt between 1939 and 1998 even though Wildlife Services helped kill 5 million predators at a cost of $1.6 billion in that time period. Two geographic areas, one that included coyotes and one that didn't, showed identical declines in the sheep industry because of unfavorable market conditions, not predator-caused losses.

A recent Associated Press story quoted livestock organizations saying that predation losses cost them more than $125 million annually. But since the National Cattlemen's Association says on its Web site that the "basic philosophy of cattlemen is to minimize direct federal involvement in agriculture," its support for taxpayer-funded programs that kill predators seems a bit hypocritical.

In almost 30 years of covering this issue, I've never been convinced that killing large numbers of predators does much good. It seems there are often unintended consequences, usually bad, when predators are drastically reduced in an ecosystem.

There may be a few limited places where predators keep big game populations low and where some control might be in order, especially when a species such as bighorn sheep is reintroduced to its native range. And ranchers deserve compensation when predators kill livestock. Still, this expensive program deserves a closer scientific look to determine its effectiveness.

Tom Wharton is an outdoors and travel columnist. Reach him at wharton@sltrib.com or 257-8909.