Ann Summers, age 11, of Tacoma, Wash., for her question:

HOW LARGE DOES AN ORANGUTAN GROW?

An orangutan is an anthropoid ape that is native to the forests of Borneo and Sumatra. The male adult reaches a height of about 4 feet 5 inches and a weight of about 150 pounds. The male is about twice the size of the female.

The male orangutan has an air sac hanging down from its throat, which it inflates and uses to make the "long call," a throaty scream easily heard almost a mile away.

Both the male and the female have reddish brown hair, which is luxuriant on the arms and thighs. Both have humanlike facial structures.

Orangutans are able to use both arms and legs to swing through high trees. They have extremely long arms that reach a span of about 7 feet. Their legs, however, are short.

The animals travel in small groups during the day, feeding on leaves and fruit. At night they rest in the forks of talk trees or on platforms built of branches and leaves.

Adult males often live alone and many groups are composed solely of females and young. Because man has cut into the orangutan's habitat, the animal has become an endangered species.