Joe Hillmer, age 11, of Portland, Ore., for his question:

HOW LARGE IS A FALCON?

Falcon is the common name for a number of hawks that are all members of the falcon family. They range in size from six inches to 24 inches in length. The female is larger than the male, which seems to be the rule with birds of prey that are active by day.

The peregrine falcon is found in all parts of the world but is now endangered. It is often trained as a hunting bird. Blue black on the head and back with white and light brown stripes on the underparts, it is about 18 inches in length.

The duck hawk is a United States variety of peregrine that is also about 18 inches in length. This bird has a wingspread of about 43 inches.

The American sparrow hawk is a small falcon that is about 10 inches long with a 22 inch wingspread. This bird eats beetles, grasshoppers and field mice.

The prairie falcon which is about the same size as the duck hawk, can be found living in the arid regions of western America.