Bald Eagles: Up Close and Sassy

By Sue Austin
Photos by Michael Whitfield and the author

A biologist in a bald eagles’ nest.

When seen from a distance, the adult eagle looks bald beacuse of its white head feathers.

As eaglets, the birds have dark head features and a darker beak.

The banded eaglets.

To help these threatened birds, we have to climb into their nests.

A rope is fastened to a climbing harness around my body. The rope stretches up among the branches to the harness on my partner, Mike Whitfield, who stands on the eagles’ nest high in the tall Douglas fir. He holds the rope in case I fall. I reach over my head, stretch to my tiptoes, and grab the first sappy limb.

One hundred feet high, I reach my destination: the nest of two bald eagles. Below is a cottonwood forest and the curving south fork of the Snake River in Idaho.

As biologists working to protect these majestic birds from extinction, Mike and I are here to place leg bands on young bald eagles.

Two dark brown bald eagle chicks perch on the nest with us—up close and sassy, hissing and snapping their beaks at us. In just eight weeks, the two-ounce gray, downy hatchlings have grown to weigh nearly twelve pounds each. The eaglets now stand more than two feet tall, with six- to seven-foot wing spans.

Their parents chatter and whistle “threat” calls. Each of them flies so close overhead that I hear the swoosh of their wings. The first few times I climbed into an eagle’s nest, I worried that the adults might attack me, but that has never happened. The parents circle overhead or perch nearby. They whistle and scream. Once you hear an eagle scream, you don’t forget it.

Protecting Bald Eagles
Bald eagles lay their eggs in the spring, and the eggs hatch about five weeks later. As winter approaches, the young birds leave the nest area in search of food.

Scientists want to know where the birds go and the routes they take. With this kind of information, people can protect the birds’ habitats. So far, bald eagles that were banded along the Snake River in Idaho have been spotted in California, Oregon, and British Columbia.

Banding young bald eagles is important. But we are careful to intrude on their territory only once because the parents are easily disturbed when the eaglets are young. Some parents have even abandoned the nest.

So we band the chicks when they are beginning to take short trips out of the nest but still depend on their parents for food and protection. The parents are not likely to abandon their young at this time.

The Eagles’ Nest
To find the nest, we have to know how bald eagles live. When bald eagles nest, they pick trees by lakes, rivers, and seashores because they like to eat fish and waterfowl. They like to nest in quiet areas concealed and shaded by a canopy of limbs in the top of a tall tree, and their nests can be huge.

Bald eagles build the largest nests of any birds in North America. Year after year, one pair of eagles uses the same nest, repairing it each season with new sticks, branches, and pine boughs. The largest eagles’ nest ever seen weighed two thousand pounds—as much as a small car.

The female builds most of the nest, weaving the sticks and branches together. She shapes the nest cup, a depression in the center less than a foot in diameter. She lines it with grass, moss, pine boughs, and feathers.

The adults watch over the area around their nest. Perched high in a tree or on a snag (a standing dead tree), these eagles probably saw us from as far as a mile away.

Handle with Care
For our own safety, we must use great care in handling young bald eagles. Their claws, or talons, are razor-sharp, and when they grab something, the talons curve in toward one another and lock into place. Mostly, they use their sharp curved beaks to snip and shred food, but the eaglets also know how to use their talons and beaks to defend themselves.

Mike and I work fast. It’s hot in the nest. Flies buzz around our heads, and ants crawl through the woven sticks. I lay the chick on its back in my lap and cover its head with a cloth. The darkness calms the bird. The nest mate hisses and snaps its beak. It puffs up its feathers to look bigger. And it never takes its eyes off us. I hold the captured bird’s legs—not taking my eyes off its talons—while Mike fits one band around each leg.

The metal bands won’t cut into the tough scales on an eagle’s leg. After we leave, the green-and-white band will be easy to see with binoculars, and the large black numbers on it will tell biologists where the bird was banded. On the other leg, a silver band gives the eagle its own identification number.

Before Mike and I climb down the tree, we collect leavings from the eagles’ meals for clues about their diet. We find feathers and webbed feet from waterfowl, and lots of trout tails. Sometimes we find fur and bones of muskrats, squirrels, and even skunks.

On the ground, we gather our gear and leave. When we are far from the nest, we stop. There’s still a chance that the parents will abandon the eaglets. I watch the parents through my binoculars. The male returns to the nest.

We have succeeded in banding two more chicks. As more hatchlings are banded, more bald eagles can be studied. And the effort to protect them can take wing.