59%
I think you will find that there are a large number of birds which can defecate while in flight including albatrosses, seagulls, pigeons and many others.
If your talking about crows then yes, they caw while flying.
they sit
They usually do it to call in birds to mate.
NO!! If they did, they wouldn't fly!
through their nose
They do cast shadows.
The skylark.
if something hits them
its a caniary
Gravity
They squint However there are not many birds that will fly during rain.