Randall Williams, age 9, of Ruland, Vt., for his question:

HOW LONG DOES AN EAGLE LIVE?

Wild eagles generally live from 20 to 30 years. In a zoo, eagles may live to be 50 years or even older.

The eagle is one of the largest and most powerful birds in the world. Eagles rank second in size only to the California condor among birds of prey in North America.

The United States chose the handsome bald eagle as its national bird in 1982.

Young eagles breed for the first time when they are about four years old, and they keep the same mates for life. But if one dies, the other usually finds another mate and breeds again the next year.

In winter, eagles may gather in areas where there is plenty of food. But during the breeding season each pair claims a territory around its nest and keeps all other eagles away.

The golden eagle defends a territory of about 20 to 60 square miles. The bald eagle holds a smaller territory. Sometimes three bald eagles nest within one mile of each other.

Nests of eagles are called eyries or aeries. Both words are pronounced: AIR EEZ.

Bald eagles usually build their eyries in the tops of tall trees that are near water. Some nest on cliffs. Golden eagles usually nest on high cliffs in the mountains.

Some eagles in Asia even nest on the ground.

Eagles build eyries mainly with sticks. Bald eagles use the same eyrie every year. Eagles often decorate the eyrie with fresh green leaves while they are using it. They add new material each year, so many old eyries are very big.

A new eyrie may be only three feet across and 18 inches deep. But an old eyrie may be about 10 feet across and 20 feet deep.

Eggs are about three inches long and two inches across. Females usually lay two eggs each year. The eggs must be kept warm for about 40 days before they hatch.

The female eagle sits on the eggs most of the time, although the male takes on the job occasionally. Also, the male brings food to the female while she is sitting.

Both parents guard the nest and take food to the young.

Eaglets are not able to tear up their own food until they are six or eight weeks old. They leave the nest when they are 11 or 12 weeks old, but they cannot fly very well at first. They stay near the eyrie for several weeks.

The parents feed the young birds for several months, until they can hunt well enough to get their own food.

Although eagles often hatch the two eggs, it is unusual for both eaglets to survive. One usually hatches two or three days before the other. The older eaglet is larger and takes more than its share of the food. It also often attacks the smaller eagle' and sometimes may kill it.