Yes they do but it's rare. My dog is constantly looking up and I've never seen anything like it. He will look up and run after birds. One time he even chased a kite that looked like a giant bird and ran until he was exactly under it and looked straight up in amazement, until I finally made him leave. Anytime a big bird flies overhead he will bark and gallop after it but my female dog rarely realizes what he's chasing because she doesn't look up as high as he does.