Eagle nests can be jaw-droppingly huge, big enough for several people to sit in, and they don’t get that big overnight.
The most colossal ones take multiple generations of eagles to build. Some parts even date as far back as 400 years.
Territorial Birds
One golden eagle nest in Montana was 18 feet tall before it finally blew over. Carbon dating revealed that some of the sticks used to build it were 400 years old, Bryan Bedrosian, conservation director at the Teton Raptor Center, told Cowboy State Daily.
“It keeps going for generations. If they’ve got a nest, especially on a cliff face where there’s a solid structure for a base, they’ll keep adding to it,” he said
Pairs of eagles stick together, and if they find a territory they like, they’ll stick around and perhaps build nests at multiple sites, raptor researcher Chuck Preston told Cowboy State Daily.
“Once they select a good territory and they can be productive there, they will stay in that territory,” he said.
Golden eagles are more likely to build nests in places such as cliff faces, while bald eagles prefer to nest in trees.
Bald eagles typically use stick or pine boughs to build their nests, while golden eagles frequently use sagebrush.
Eagles can get creative and use other materials, such as deer antlers, Bedrosian said.
Size Comes In Handy
One popular photo shows a Park Service ranger sitting in an eagle’s nest, which is big enough for several more rangers to join him.
Such super-sized nests are hardly unheard of, Bedrosian said.
“They’re not all that big, but definitely, a lot of them are,” he said.
Of course, young eagle couples also have starter homes.
“On the other end of the scale, there are eagle nests that are relatively tiny,” he said.
Whenever it’s possible, eagles like to have lots of space, Preston said.
For one thing, it comes in handy for eating or feeding their young.
“That big platform helps keep the prey from falling off,” he said.
Wyoming, Eagle Winter Wonderland
Wyoming has resident populations of both golden and bald eagles. Both species are opportunists when it comes to food and will eat what they can get – including roadkill or winterkill big game carcasses.
But in general terms, golden eagles favor rabbits. Bald eagles are fond of fish, so they are more likely to nest in trees near water sources.
Wyoming’s vast open lands are where golden eagles prefer to be. Some hot spots include the Bighorn Basin in northwest Wyoming, or the sagebrush seas in the central part of the state.
During the winter, golden eagles migrate from the north, sometimes as far away as Alaska. Wyoming’s golden eagle population essentially doubles, to 10,0000 or more, Bedrosian said.
Bald eagles are more common; they number in the hundreds of thousands across the West, he added.
A disease outbreak in 2020 killed many of the cottontail rabbits in the Bighorn Basin, Preston said. That left the golden eagles with slim pickings, although jackrabbits made a for a good alternative food source.
“This year is the first year that they (cottontail rabbits) have started to rebound,” he said.
Raptor researcher Chuck Preston stands under a huge golden eagle nest in the Bighorn Basin in northwest Wyoming. (Courtesy C.R. Preston) 
Eagles’ nests are huge, sometimes weighing more 1,000 pounds, and it takes generations of the raptors to build them. The most colossal ones can be big enough to seat several people inside. At Heuston Woods State Park in Ohio, a replica bald eagle nest allows people to climb in and see just how huge they can get. (Heuston Woods State Park) 
A 9-week-old fledgling golden eagle is pictured here, nearly ready to leave its parents’ nest in the Bighorn Basin in northwest Wyoming. (Courtesy C.R. Preston) 
Eagles’ nests are huge, sometimes weighing more 1,000 pounds, and it takes generations of the raptors to build them. The most colossal ones can be big enough to seat several people inside. (Getty Images) 
Eagles’ nests are huge, sometimes weighing more 1,000 pounds, and it takes generations of the raptors to build them. The most colossal ones can be big enough to seat several people inside. (Getty Images)
Eagle Divorces
Eagles typically live about 20-25 years in the wild, and a few make it into their 30s, Bedrosian said.
They mate around age 5, almost always for life.
“There are such things as divorces, essentially,” Preston said. If they’re not really successful over a couple of years, there are some reports of pairs breaking up,”
Otherwise, it’s until death does the eagles part, he said.
An eagle that loses its mate might select another – but usually not for at least a year or so, Preston said.
Prairie Living
While bald eagles are usually associated with water and golden eagles with vast sage flats, both species – along with other raptors – have been taking to the prairies, Bedrosian said.
In Converse County, a recent raptor survey found eight nests in plains habitat, he said. In most cases, eagles are using huge cottonwood trees to build nests.
While that’s good news for raptor conservationists, it’s bad news for burrowing rodents.
“They’re after the prairie dogs there,” Bedrosian said.
Mark Heinz can be reached at mark@cowboystatedaily.com.
