If there's a major staging area for ducks, geese, swans or cranes within a day's drive of where you live, spend a weekend chasing waterfowl with field glasses. If the migration is already over in your part of the country, take a kid out to watch resident ducks or geese nesting. Explain some of the facts of the natural world, like what those birds must do to protect their nests and youngsters from predation. It's not just gamebirds that put on a spectacular show each spring. Take a camera and look anything from egrets or hummingbirds or cedar waxwings.
Any bird is worth watching, and spring is a great time to look.
The weeks before the leaves thicken offer a rare, unobstructed view of all sorts of birds. If there are pheasants where you live, drive around the countryside looking for a big old rooster defending his harem of hens. Few sights in the outdoors are as spectacular as a pair of roosters doing battle. Except, perhaps, woodcock singing. If they're not already on the ground, there will soon be newborn fawns waddling about on shaky legs.