When Sheep Become An Eagle's Diet

May 8, 2020

Part of a rancher's daily life is dealing with threats to their livestock. And one of the almost impossible threats to try and solve is depredation - especially if the culprit is a protected species, like the golden eagle.

They can be massive. With an almost seven and a half feet wide wingspan, they can weigh up to fifteen pounds. And, according to wildlife biologist and long-time eagle researcher, Charles Preston, they're incredibly capable hunters.

"They have quite a broad diet, very diverse, depending on where they live and what's available. In general, their favorite food is about size. It's usually medium-sized mammals. But in addition to that, they certainly can and do take foxes, even carnivores the size of coyotes," said Preston.

For the most part, golden eagle populations in Wyoming are stable or slowly declining.

But a lot of the expansion is being done by ranchers, which, according to Preston, means their livestock may start to replace some of the eagle's natural prey—which has been pushed out by human development.

"We find that in most cases where eagles take livestock, at least on a regular basis, it's because their native prey is not available or not abundant, usually due to habitat quality issues," said Preston. "The habitat is just not there supporting the native prey. And here's a nice source of food in the form of a sheep or lamb or small calf."

And while that's good news for the eagles, it's not so great news for the ranchers. Brandi Forgey owns Forgey Land and Livestock with her husband, Keith. They raise Angus cattle and two different kinds of sheep. The Forgeys have about 2,400 sheep and each year their ewes give birth to about 2,100 lambs. But Brandi estimated they lose at least 150 to 250 every year to predators. And she said the worst depredation is on their lambs.

"It could be any of them. I mean, some people have trouble with their calves or whatever. For us, mainly, it's lambs. We get a few ewes, yearlings, once in a while, but definitely lambs with the eagles and the coyotes," said Forgey. "So I'd definitely say it's mainly the lambs where we have our biggest problem."

But golden eagles are a protected species. Plus, they're covered by two laws: The Migratory Bird Act and the Bald and Golden Eagle Protection Act.

Lambs who are injured or whose mothers have died live near the house and are reintroduced to the herd once they're healthy and an appropriate size.
Credit Ivy Engel

This means that the Forgeys, or any other rancher, can't kill them to protect their stock. They can't even scare the birds off - they need a special hazing permit for that.

"So if we're having trouble say, I'm just using us as example, if we're having a lot of trouble with eagles, and a lot of times it's more Golden Eagles, then you can get a permit to kind of harass them a little bit like loud noises and whatnot," said Forgey.

A different permit allows falconers to remove golden eagles for ranchers, but the U.S. Fish and Wildlife Service only lets six eagles in the entire country to be taken from the wild each year for falconry. Trapped goldens can also be relocated, but they often find their way back or start causing issues for other ranchers.

Mike Foster is the state director for the USDA Wildlife Services Program. His office is the one ranchers call if they have a predator problem.

According to Foster, the best way ranchers can increase their chances of getting one of those permits is to document the cause of all depredation. But when most herds are in large pastures and scavengers are abundant, proper documentation can be very difficult, even for professionals.

"And that's one of the challenges that ranchers have is finding these kills out on a large landscape like we have in Wyoming. Finding them in time so they can call us, Wildlife Services, and we can get out there and investigate it before a coyote comes along and finishes eating it or something like that," said Foster.

There is one other option for ranchers. It's a small pot of money offered by Farm Services to compensate for eagle losses.

While eagles are usually responsible for a small percentage of all depredation ranchers deal with, they tend to target ranches for several years in a row, which can cause major losses in the long run. In other words, none of these solutions are perfect. In fact, Foster speculates that he doesn't get as many calls about eagle depredation as is actually happening since not a lot can be done.

"Why call and have it documented if there's nothing you can do?" he said. "A lot of ranchers frankly don't even know that there's an option out there. They know that eagles are protected. They don't know of anything they can do, and so they don't call," said Foster.

Have a question about this story? Contact the reporter, Ivy Engel, at iengel@uwyo.edu.