Show the preschoolers posters, photos and flashcards of different bird species. You might also show them well-illustrated books on birds and bird videos.
Ask them to tell you about any birds they have seen and have them describe them to you. Talk about how some birds like hummingbirds are small and some like the ostrich are large; how some like the cassowary bird have crests and some like the peacock boast colorful tails. Show them that some like Amazonian macaws have bright-colored plumage and some like the common wrens are quite plain. Many like the owl have short beaks and others like the ibis have long curving ones.
Talk about where birds live: Some like the emu live on the ground and some like the swan on water. Penguins are found in snow-bound lands and others like the roadrunner dwell in the desert. Birds like the sparrows build nests and many like the woodpeckers make holes in tree trunks. Talk about what birds eat and the kinds of sounds birds make.
Now put away all the bird posters, photos, flashcards and books. Hand out drawing sheets, colors, old magazine pages, colored paper and other paraphernalia. Make sure there's plenty, so if anyone wants more drawing sheets they can have them.
Ask the preschoolers to imagine and paint birds. The birds can be of any color, shape or size. They can paint one bird or several birds. The birds can be eating, sleeping, flying, playing, singing, sitting, etc. They can live in a jungle or a bungalow. There are no restrictions. They can even have three legs, as a friend of mine once portrayed; that's why this bird is in the rare section in the zoo, he said.
Pose the 'What if...?' question. What if a crow is flying an airplane? What if a turkey rides a bicycle? What if a pigeon plays in a music band? What if there was a giant hen?
The children can paint with brushes or with their fingers. You can slice raw potatoes in half for them and carve a design on the half. The preschoolers can then dip the potato half in color paint and stamp interesting shapes on paper. The children can use scissors to cut up the magazine pages and colored paper or tear them up. The torn or cut pieces can then be used to form a collage.
Walk around and see what the kids are doing. Encourage and make suggestions, if necessary; otherwise let the preschoolers get along on their own steam.