Julie Merritt, age 15, of Bountiful, Utah, for her question:

How do hummingbirds survive the winter?

Would you believe that a tiny little hummingbird can fly more than a thousand miles? Well, he can. Every year, the sturdy little rufous hummer flies from Mexico to southern Alaska    and back again. Would you believe a hummer can fly non stop for 600 miles across the salty sea? Many ruby throated hummers do this twice every year, when they cross the Gulf of Mexico between their winter and summer homes.

Hummingbirds feed on insects and flower nectar and in most parts of North America, these food items depart with the summer. So come fall, the hummers migrate southward to mild winter regions. Or at least most of them do. At least one of the bejeweled midgets spends the winter in California or southern Arizona. All the other species that spend the summer nesting season in North America migrate to Mexico or even farther south.

At least 15 hummer species make their summer homes in western North America. But only the ruby throated hummingbird visits east of the Missis¬sippi River. The male, all of three inches long, wears a glistening red bib and the female wears a neat white bib. Come fall, these mighty mini¬birds stoke up on bugs and nectar for the long flight southward. Some fly down from Alberta and Saskatchewan, Manitoba and New England where they have spent the summer. The route leads south to the Gulf of Mexico    where they fly 500 or 600 miles non stop across the open water.

A few ruby throats may decide to winter in southern Florida, Texas or Louisiana. But most of them continue on down to Mexico, Panama and other parts of Central America. In early spring, they set fotth on the return flight and spread out across most of North America.

The broad tailed hummingbird looks somewhat like the ruby throat, though he favors the Western mountains. He reaches the lower slopes in spring, just in time for the cactus blossoms. Later he flies all the way up to the gorgeous wild flowers that bloom at 12,000 feet. In the fall, this whirring wonder departs for Mexico or the high slopes of Guatamala.

These migration journeys seem almost impossible. But the rufous hummer does even better. This sturdy midget is the same color and weight as a shiny copper penny. One of his favorite summer homes is way up there in southern Alaska    and come fall he flies down to Mexico. Many other migrating species can be seen en route, if you know just where and when to look.

California's favorite is the Anna's hummingbird    because he happens to be a permanent resident. The sassy little male wears a jacket of irridescent green, a cap of glistening ruby red and a neat white necklace. The female, like most lady hummers, wears modest green and brown.