Lori Ann Livingston, age 10, of Niagara Falls, Ontario, Canada, for her question¬

Why do birds bother to come back in the spring?

Birds are tough little creatures with warm feathery coats. Most people think that they fly south in the fall to escape the cold. But actually most of them could cope with our wintry weather. There is another more important reason why they fly south in the fall. And this is the same reason why they fly back here to nest in the spring.

We can find this answer by watching the bird world    by noticing the habits of different species, what they eat, how and where they live. If we observe with patient, friendly eyes, nature rewards us with a special gift. Without knowing it, we grow an extra bump of understanding. We gain a bird's eye view of life and know a little about what it's like to be a bird. This view helps us answer many bird questions that pop into our heads.

For example, we can trace the roundabout reasons why birds bother to come back to us in the spring. True, it seems logical for them to stay south where both summers and winters are warm. But they don't    and the main reason is food. For his size, a busy little bird is a very big eater. His special personal diet may be weed seeds or water weeds, worms or assorted insects or maybe frogs and fishes. In any case, he snacks all the time and he may eat his own weight in food every day.

Chances are, the sturdy birds could stand the winter's cold. But come fall, the plants die down and the insect population goes into hiding. This food shortage is the main reason why swallows and swifts, wrens and warblers and dozens of others flock south to mild winter climates. There they find enough groceries to keep them alive. However, these winter homes are very crowded with all sorts of migrating birds. Usually, there is enough food for all    but none to spare.

Grown birds can survive on short winter rations    but famished baby birds require far more food than their parents. So as nesting time approaches, the parents prepare to depart. In early spring they flock north and spread out far and wide across the land to raise their families. The parents build the nest where there is a large area to hunt for all that baby food. And, naturally, they arrive in time to welcome the spring greenery and greet the first swarms of insects. With all these rewards waiting, surely the long journey seems like no bother at all.

Wild ducks and many other birds spend the winter by our lakes and swampy shores. In spring they depart for their nesting grounds in the far north. There., where the sunny air swarms with insects and the ground bursts with tender plants, the young ones feed and thrive. Come fall, the snow buries the plants and the frost freezes the ponds. The birds with their grown families then flock south to spend the winter.