Nice work on this one! It does play itself for the most part, so I wonder if a better way of doing it would be to not have the pipes move randomly but rather arrange them in such a way that the birds don't clear the course unless you change things. As another commenter said, I usually only lost birds when I moved the pipes.
Another possible upgrade would be the ability to see the birds' flight path to know if it is safe or not. This would allow you to make the game much more difficult I think.
Even as it is however, this is pleasant to look at and I still had fun watching the birds go.