But they can fly vertically. You are right though, flying straight up is a good evasive maneuver, but they probably are not as fast as a drone flying vertically unless it’s a hummingbird- they are hella fast in any direction, especially while...
I have red and white reflective tape all over my drone for visibility- especially if it goes down as it would be easy to see with a spotlight. I also used it as part of my nighttime flight waiver back when FAA required one. But birds won’t leave...