Explain to the children the similarity of birds and airplanes. Talk about how both have wings and how they are used.
Throw a paper airplane so it sails across the room. Talk to the children about how a bird would do the same thing. Explain that birds must flap their wings up and down to propel themselves in the same manner.
Bend a section of one paper airplane wing down. Throw the paper airplane across the room. Talk with the children about the way the paper airplane flew. Explain how a bird with a damaged wing, possibly from the loss of feathers, would fly in the same manner.
Cut a section off one paper airplane wing or cut off the entire wing. Throw the paper airplane across the room. Talk with the children about the way the paper airplane flew. Explain how a bird with a severed or broken wing would not be able to fly.