TWIN FALLS, Idaho (AP) — State wildlife officials plan to spend up to $100,000 during the next two years poisoning ravens in three Idaho areas in an attempt to boost sage grouse populations.

Idaho Fish and Game wants to kill as many as 4,000 ravens by placing poisoned chicken eggs in strategic locations beginning later this spring.

“We can’t directly say that (sage grouse population decline) is from ravens, because we don’t have that information,” biologist Ann Moser said. “There’s anecdotal information.”

Attempts to kill ravens by shooting them didn’t work well, she said.

“We tried that, but ravens are very smart, and they are not easy to shoot,” she said.

The agency is targeting ravens in eastern Idaho near Idaho National Laboratory as well as Curlew National Grasslands and Washington County near the Oregon border.

Moser said the poison in the eggs only kills birds of the corvid family, which includes crows, ravens and magpies.

“If a dog came and picked up an egg, it would not affect the dog. If a dog picked up a raven that died from the poison, that would not affect it either,” she said.

Sage grouse are chicken-sized birds that have been in decline across large portions of 11 western states. A final decision by federal officials on whether to protect sage grouse is due next year and could result in wide-ranging restrictions on oil and gas development, agriculture and other economic activity. Possible grazing restrictions could also be put in place.

A draft environmental impact statement and six management alternatives by the U.S. Bureau of Land Management and the Forest Service list the top three threats to sage grouse in Idaho as invasive plants, infrastructure and fire. Predation ranks tenth.

“If there is an egg predation problem, I would say the first thing is that it is a cover problem,” said Alison Holloran, regional science director for Audubon Rockies. “It is not a raven problem — it is a habitat problem.”

Jared Brackett, a rancher in Rogerson and president of the Idaho Cattle Association, said sage grouse are being used to eliminate grazing on public lands in the West. If the birds are listed under the Endangered Species Act, it could lead to the closing of grazing allotments on public lands, he said.

Brackett said poisoning ravens is a good idea.

“These birds of prey populations have exploded,” he said. “You can’t tell me that predation on nesting birds is not a factor, and that’s why we are very happy to see it.”

Moser said the human factors that have allowed ravens to expand are the same ones at work causing declining sage grouse numbers. She said officials will keep track of raven populations to determine if the poisoning results in fewer ravens.

“We’re pretty sure that once you remove a territorial pair of ravens, somebody else is going to move right in,” Moser said. “We are hoping to pick that up in our raven surveys — are we really seeing a (raven) decline or not?”