CODY, Wyo. — The USDA's practice of lethally removing wildlife from the landscape is counterproductive, favors certain game animals and fails to serve any long-term goals, the American Society of Mammalogists says in a letter to the agency.
The ASM, a scientific organization with 3,000 members from 50 states and 60 countries, is asking the USDA's Wildlife Services division to move away from the practice of lethal removal — killing — and focus instead on building public education to reduce the need for exterminating wildlife.
The group of biologists and educators is asking the USDA to reduce funding for its lethal control efforts and to reshape a program that, it says, has changed little from the days when the Bureau of Biological Survey waged a war against wolves and prairie dogs a century ago.
"We see from Wildlife Services a heavy and inflexible emphasis on lethal control and a lack of scientific self-assessments," ASM writes.
Citing federal data, ASM says that between 2000 and 2010, agents with Wildlife Services used aerial gunning, trapping and poisoning, among other methods, to kill more than 2 million wild mammals across the U.S.
The numbers include roughly 916,000 coyotes, 321,000 beavers, 126,000 raccoons and 84,000 skunks. They also include 3,000 wolves, 4,000 mountain lions, 4,500 bears, 19,000 muskrats, 29,000 opossums and 25,000 marmots and woodchucks.
ASM argues that the numbers are consistent each year, implying that either the killings are creating population "sinks" that quickly fill, or that reproduction is compensating for the increased mortality.
"We have no real data on the effects of this lethal control on the populations of target or non-target species because there is very little monitoring being done," ASM said.
Carol Bannerman, spokeswoman for Wildlife Services in Maryland, said the agency's data suggest that nationally, it euthanizes just 11 percent of animals on calls while using nonlethal means to remove animals 88 percent of the time.
Bannerman said 75 percent of the agency's research budget goes to nonlethal removal of wildlife. She said the agency also has made changes over the years.
"We've added a staff person out of Fort Collins whose entire job is to look at nonlethal methods and help our own staff, as well as those people we work with, use nonlethal methods where they can be effective," Bannerman said.
Bannerman said lethal removal is higher when it comes to invasive species, such as feral swine, brown tree snakes or nutria — a South American rodent that causes damage in U.S. coastal areas.
"We do not seek the eradication of any native species," Bannerman said. "We try to address the damage in a particular area where it's occurring."
In its letter, ASM takes particular aim at Wildlife Services for its killing of prairie dogs and gray wolves, both native in Montana and Wyoming.
Killing a large number of carnivores, ASM argues, has had unintentional impacts on other species and the ecosystem.
"A massive campaign to exterminate wolves and coyotes across the West was begun in the early 1900s," AMS said. "By the 1920s, rabbits had so overpopulated the region that another massive campaign was begun to reduce their numbers.
"Apparently, Wildlife Services never did make the obvious connection between coyote control efforts and rabbit population numbers."
The extermination of prairie dogs is also a problem, AMS said. Roughly 77 percent of prairie dogs killed in the last decade were exterminated in 2009, the group said, even as efforts to restore the black-footed ferret, which depends upon prairie dogs, were being made.
Efforts to reduce prairie dog numbers have had cascading effects on the quality of grassland ecosystems.
"Not only have species associated with prairie dogs declined, but their loss has resulted in the invasion of desert shrubs into North America's grasslands," the group said.
ASM is also critical of the means Wildlife Services uses when practicing lethal removal, such as trapping, aerial gunning and the deployment of M-44s, which release a deadly sodium cyanide spray when triggered by predators.
Bannerman said the EPA reviewed the agency's use of M-44s, as well as livestock protection collars, and found they had no significant impact to human beings or the environment.
"We seek to do it as humanely as we can," Bannerman said. "There are differing opinions on that. As for the livestock protection collars, the only animal harmed is the animal biting the neck of the sheep."
Wyoming Agriculture Statistics Services reported that in 2010, producers lost 16,800 sheep and lambs to predators, valued at around $1.4 million. Roughly $1.5 million in cattle and calves were also lost in Wyoming to predation in 2008, the last year for which figures are available.
In Montana in 2010, predation resulted in around $1.7 million in losses for Montana's sheep industry. Cattle predation has also increased over the last six years, the USDA says.
ASM said the tactics used by Wildlife Services aren't working.
"It's clear that the ongoing slaughter (of coyotes) has not brought about any long-term solution to the perceived problem," AMS said. "It's estimated that at least 5 taxpayer dollars are expended to kill every coyote that is deemed responsible for the loss of one dollar's worth of livestock."