Three weeks after hatching, eagle chicks, or eaglets, molt to a thicker, darker down which remains until the first set of feathers develop. At this stage, one of the parents remains near the nest to shelter the chicks from direct sunlight, inclement weather, and anything else that can harm them.

When an eaglet first hatches, its bill and eyes are dark-colored. Over the course of three to four years, the bill lightens to a swirl of shades of brown, then to yellow-brown, and finally to bright yellow. The eyes lighten to buff yellow by one-and-one-half-years, light cream by age two-and-one-half, and pale yellow by three-and-one-half.

As the chicks develop feathers and grow, the parents spend less time at the nest and more time hunting for food. The eaglets grow very rapidly as long as the parents can provide sufficient food. If the parents are unable to find enough food, the smallest chicks might die.

At one-and-one-half to two-weeks, most young eagles weigh one to two lbs. (500 to 900 grams). Between 18 – 24 days, chicks gain four ounces (100-130 grams) per day, a faster weight gain than at any other stage of their development. Eaglets begin feeding themselves around the sixth to seventh week, and by eight weeks, they can stand and walk around the nest. At sixty days, eaglets are well-feathered and have gained 90% of their adult weight. Large nestlings consume nearly as much food as adults.

Chicks remain in the nest for ten to twelve weeks. A week or two before they fledge, they can be seen on the rim of the nest exercising their wings and holding onto the nest with their talons. They flap their wings and may even lift off the nest. A chick can fall or be blown off a nest while exercising, and if it can’t make it to another branch, it might fall to its death. Biologists estimate one in seven eaglets fledges prematurely, either falling or jumping from the nest before it can fly.

Once their muscles and wings are strong enough, eaglets are ready to leave the nest. What prompts the chicks to fledge is a matter of speculation, but at some point, the parents cut back on the amount of food they provide their young, and they may even use food to lure the chicks away from the nest. Males fledge at an average of 78 days, and females fledge at an average of 82 days. Research in Southeast Alaska shows fledging there occurs on average in mid-August.

The first several flights of a fledgling are very clumsy, and their first few landings are usually crash landings. Juvenile birds have longer wings and tails than adults, and this makes learning to fly easier for them. As an eagle matures, its wings become shorter and narrower, and the tail gets shorter with each molt.

Immature eagles usually stay within a half-mile radius of the nest for the first six weeks after fledging, and they may even continue to receive food from their parents during this time. Eight to ten weeks after fledging, they seem to develop a stronger instinct to move further away from the nest.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.