You can sound like a bird if you know how to make the relevant bird call. Children often imitate bird calls in their games, and you can join in with your kids if you know how. One of the more popular and simpler calls to make is an owl's hoot. Your kids will probably learn how to do this on the playground, and you can also make a realistic owl call using just your hands and your mouth.
Clasp your hands together. Keep both thumbs upright and pressed against each other.
Create a void between your hands by widening the clasp of your fingers. Make sure you don't let air escape though.
Bend the tops of your thumbs over a little, away from you.
Open your mouth slightly and curl your lips around your teeth a little bit. Press you lips against the top joint in your thumbs then blow through and down into your hands.