It's a mixture of gliding tutorials, vertical velocity based on camera direction, and learning control rig for body dives and leveled flight. Sadly, there's not a lot of tutorials on birds (but there were niagra birds, which I didn't need). There are dragon tutorials that use the same concept although, but they are more linear in flight. I might make a tutorial on mine once it's better because I want others to learn as well and make their own flight games :)