Cut out large duck shapes and let the kids glue yellow cotton balls on them, or yellow felt looks nice as well.
Draw a outline of a duck (very basic), on paper then give the kids a scrap piece of yellow paper have them rip small feathers and glue them inside of your outlined duck. The more layered and different shape and sizes the better. Finish by gluing or drawing some feet and glue an orange bill and black eyes.
This can be done with children of all ages. Give each child a feather and let them paint with it. You can let the feather stick to the paint for an added effect/texture!