The majestic golden eagle visits North Idaho

This is one of the largest birds of prey in Idaho and the national bird of Mexico. These birds are dark brown, with lighter golden-brown plumage on their heads and necks. They are extremely swift, and can dive upon their quarry at speeds of more than 150 miles per hour.

Golden eagles (Aquila chrysaetos) use their speed and sharp talons to snatch up rabbits, marmots and ground squirrels. They also eat carrion, reptiles, birds, fish, and smaller fare such as large insects. They also have been known to attack a full-grown deer.

Idaho has three populations of golden eagles during the year:

- Migrating birds traveling through the state;

- Wintering birds from the north;

- Non-migratory birds that are breeding or nesting at this latitude. Their home range runs approximately 6-8 miles from the nest during the year.

Most golden eagles tend to stay in the area year-round, but after breeding, they tend to stray from their territory for 100 to 200 miles for a few weeks and travel around. That distance is minor in the world of raptor movement. Some eagles in Alaska are totally migratory, with movement south through Mexico. Their motive is all about food — they go where the prey is.

Golden eagles have large bodies and long, broad wings with very distinct, fingerlike feathers at the tips. They usually soar for long periods without flapping their wings and can often be seen doing spectacular mating displays in the sky during the spring. The buff–colored “helmet” of feathers on its head and neck gives the golden eagle its name.

Immature goldens look much like young bald eagles except for a white patch at the base of the tail and on the underwings. The adult’s brown to dark brown plumage appears at about age four. In size, golden eagles are similar to bald eagles.

Golden eagles weigh 9 to 12 pounds, but they can lift two to three pounds off a level surface. Golden eagles have been seen taking a wide range of prey, including coyote pups, deer fawns, marmots, game birds and a variety of small mammals. They also have ways of taking bigger game. When they know a mountain goat or bighorn lamb is on a cliff, they’ll fly at an angle and knock it off, letting it fall to its death or holding on and gliding to the ground.

In the big picture, however, the decline of jack rabbits, ground squirrels and shrub-steppe habitat may have the biggest cumulative impact on the eagles. Adult golden eagles tend to soar above the dangers of predation, but they’re vulnerable to a wide range of human-caused deaths, especially electrocution from power lines and lead poisoning.

Golden eagle pairs maintain territories that may be as large as 60 square miles. They are monogamous and may remain with their mate for several years or possibly for life. Golden eagles nest in high places including cliffs, trees, or human structures such as telephone poles. They build huge nests to which they may return for several breeding years. Females lay from one to four eggs, and both parents incubate them for 40 to 45 days. Typically, one or two young survive to fledge in about three months.

Nestlings are fed only what a parent can carry back to the nest, since eagles, unlike vultures, don’t regurgitate food. Juvenile eagles are vulnerable to predators such as great horned owls. They’re most vulnerable to wild cats and coyotes when they’re learning to fly.

The life expectancy for a golden eagle in the wild is approximately 20 years.