BOISE - Four conservation groups that contend that federal officials in Idaho are violating environmental laws by killing predators and other wildlife to protect livestock and crops have taken the first step to file a lawsuit.

Idaho-based Western Watersheds Project and three other groups sent a letter to the Idaho office of the U.S. Department of Agriculture's Wildlife Services as a 60-day notice of their intention to sue in federal court.

The letter sent last week requests that the agency cease activities and conduct an environmental analysis or a more involved environmental impact statement, which includes public participation.

"Idaho is so ecologically important for wildlife, particularly carnivores," said Kristin Ruether, an attorney at Boise-based Advocates for the West who is representing the environmental groups. "Central Idaho is one of the wildest places in the lower 48."

A spokeswoman for Wildlife Services said she couldn't comment specifically about pending litigation.

The groups contend that a biological opinion issued in July violates the Endangered Species Act. That opinion says the agency's proposal for wildlife damage management won't harm threatened bull trout, grizzly bears and Canada lynx. The groups also say that environmental assessments issued in previous years that found no significant impacts violate the National Environmental Policy Act.

The documents, the groups say, contain conclusions based on outdated information.

"Over the past decade, and especially in the last three years, there's been a lot of research that shows the benefits of having carnivores on the landscape," said Andrea Santarsiere, an attorney at Center for Biological Diversity, one of the groups that sent the letter.

The groups said the agency is using a century-old mindset in killing wolves, bears, coyotes, beavers, badgers and other animals while ignoring information from recent studies, some stemming from the reintroduction of wolves in Yellowstone National Park.

In fiscal year 2013, the most recent information available on the federal agency's website, the agency in Idaho killed 77 wolves, some 2,700 coyotes, seven mountain lions, three black bears and 24 badgers.

The agency's wildlife management policies are "based on antiquated ideas that don't recognize how important predators are to ecosystems," said Amy Atwood, also an attorney at the Center for Biological Diversity.

Carol Bannerman, a U.S. Department of Agriculture spokeswoman, said the agency knows that people won't agree with agency at all times.

"We understand that not everyone agrees with everything we do," she said. "But professional wildlife management agencies have identified that removal of animals causing damage is a responsible part of wildlife management."

Bannerman also noted that the agency works to protect native species by eliminating those that are invasive. In Idaho, for example, the agency killed nearly 200,000 European starlings last year.

"More than 50 percent of the animals lethally removed are invasive species," she said.

The environmental groups also take issue with the killing of beavers in Idaho, 43 last year, because they say beaver ponds are rearing habitat for bull trout. They said the agency only studied the effects of the explosion of blowing up the dams on bull trout, not on the removal and draining of the ponds.

Also participating in the potential lawsuit are WildEarth Guardians and the northern Idaho-based Friends of the Clearwater.

"We'd really like to see Wildlife Services and its program ended all over the West," said Travis Bruner, executive director of Western Watersheds Project. "Idaho is a good place to start."