As a kid I love climbing, too, including coconut trees, mango, electrical post, flag pole, even bamboo which bends over. After falling couple of times, I ended up with this damn fear. My last fall which is roof height cutting/trimming tree branches was the scariest because I landed head first--took more than a month to heal my neck, back, shoulder. I can't even lie down and have to brace my neck. I sprained my neck severely followed by my shoulder and back. I may have lost 10 pounds of body weight. Obviously I cut my elbows, forearms, shins, etc.
Now every time I see someone at the roof I ended up hoping for their safety and always tell them to be careful.
I supposed your birds range from short distance speed bird to long distance marathoner then. That would be confusing. Some of my birds I think are sprint, medium and long distance just like yours and their speed difference is obvious. Sprint birds get to leave everyone behind. Long distance birds seem rather slow almost like taking their time in the air. It is even funny with head wind. Those birds are like just floating going nowhere. Obviously I am talking about 20 mph head wind loft flying. I want my birds' asses to feel the difficulty of flying. Some of my birds even prefer bad weather! They dart back and forth, diving, rocketing up like they are suicidal. But it is a very good show when they buzz you. I am talking about my speed birds here.