Nancy Hansen, age 12, of Newport Beach, Calif., for her question:

HOW FAST DO A HUMMINGBIRD'S WINGS BEAT?

Suppose Americans forgot their present troubles and honestly set about listing their real treasures. Surely the little jewel toned hummingbirds would be near the top of the list. What's more, these gorgeous little birds have other qualities besides their beauty. They are among the fastest and most fantastic aerial acrobats in the entire bird world.

This is a good time of year to watch a parent hummer, searching among the flowers for bugs and nectar. He darts like an arrow, turns on a dime and hovers like a helicopter. His busy wings look like a blur because they beat too fast for the human eye to follow. They. may beat from 50 to 70 times per second. At his top speed his darting flights have been clocked at 71 miles an hour ¬which may be the record for fast flight in the speedy bird world.