Lots of good points Bat!
I don't want you to get the wrong idea as to my opinion of "freedom" when it comes to animals. I'm absolutely, completely, in favor of having animals in captivity, using them in a "humane" sense (although that term is one I question too), killing them, eating them, wearing parts of them, etc... Animal use doesn't bother me in the slightest.
Yes, my birds are absolutely "happiest" when I'm not around. Especially if they've just eaten. They don't hang around because they like me, they don't get excited to see me, or excited when I get home (like my dogs do). They're not social animals, they don't even "like" their mates; they just allow them to share a territory.
My birds do get very "interested" when I approach at certain times, or in a certain manner, because they know that hunting and feeding is coming up. They're not excited about me, but what my approach represents.
From what I've experienced with my birds, they "use" me, as much as I "use" them. My birds are for hunting. I also use them for education, and falconers as a whole have acquired knowledge that has made the restoration of birds of prey (such as the bald eagle, and peregrine falcon) as well as the rehabilitation of injured birds of prey, and care of "display" birds (such as at zoo's) possible, productive, and successful. They're not really given the credit they're due in those respects, but the knowledge they've shared in those respects has been vital. The knowledge gained through 4000 years of caring for and hunting with these birds teaches things that are difficult (if even possible) to gain through regular field study.
As I said, my birds are for hunting. They "use" me as a flushing tool. I basically become the masters dog. My birds follow me around through the air or trees (depending on what type I'm flying) and come to learn very quickly that their hunting success goes up with me, and that I'll "help" them if they grab things that are a challenge (size-wise, mostly) and I give them food for behavior that I like. In their minds, I never take food away, but I do give it to them (in fact, I do take away their kills, they just don't realize it). Sitting in a tree by themselves, they may see one or two rabbits/pheasants a day. Following me around, they'll see 8-10 per hour... They're flying free, so they come back by "choice" (Jedi mind-leash?), although they are trained to do that, and don't have any comprehension of "captive" vs "free". They want to eat, and then wait until they get hungry enough to eat again.
They make terrible pets. If I wasn't hunting with them, I wouldn't have them.
My main interest in the birds is for fun/sport. I can also feed my family to some extent with them. They give me enjoyment, much more-so than any of my other animals. It's basically hardcore bird watching. Although they give me a lot of enjoyment, I wouldn't say we have too much of a "relationship". Once they're fed, they don't want me around. They're not scared of me, but they don't "like" me... What I didn't so much expect when I got into falconry was how much more I would learn, and how much enjoyment that would bring me (and to others, as I do a fair amount of educational work with the birds). It's given me much more insight into predator/prey dynamics for sure, and taught me how wrong the fairytale myth they teach us in school is (the one where they make it sound like predators only kill the sick/weak animals, and only kill what they can eat, to start with). I've been studying birds of prey as best I could in school and college (loads of biology, zoology, etc). But, I learned more in 6 months of hands-on work with my first bird than I did in my previous 30 years.
What does the bird get from it? Individually, a better chance at survival. Species-wise, nothing. In the wild, redtails suffer a 65% mortality rate their first year. 35% make it to 1 year old, in other words. 1 year olds have a 35-40% chance of making it to their second birthday. Those odds pretty much continue each year. Only 5-10% make it to their breeding age of three years old. A really old redtail in the wild makes it to about 8 years. In captivity they make it to 30 or more. There's still a mortality rate in falconry of course, but it's closer to 5%. Most of my birds are trapped as immature birds, and later released once they hit breeding age. Falconry could be considered the one true "green" sport. It has zero impact on the birds as a whole, and zero impact on the quarry a a whole. "My" birds would be hunting and killing, living and dying, even if they weren't "my" birds.
Bald eagles fair better nowadays, mainly due to them being such an item of interest and effort, and the heightened awareness amongst the public this has generated. By getting so much of their food through scavenging and thievery (they're a lot like pretty seagulls), they may also avoid many of the injuries that would kill a redtail. A redtail may kill and eat a squirrel, but if it hurts itself in the process, it'll die. It could be as simple as a bite on the foot that gets infected. My birds go to the vet when they need it, and get fed whether they succeed in the field or not. Failing to learn to hunt well enough, fast enough, in addition to injuries suffered in the process is responsible for a large percentage of raptor mortality.
What about those that die along the way? Should they be saved if possible? I tend to say no! Allowing the "less fit" to survive and breed goes against the grain of "natural selection". When it comes to raptor rehabilitation, I'm skeptical of at least some of it. For one, the low number of birds that are rehabbed aren't likely to effect the overall population. If they're "less fit" than other specimens, is it proper to save them and let them breed? If the overall population isn't in danger, and only a small percentage are "saved", what's the point? In a case where the bird loses mobility, what is the quality of life going to be? If it's really "upset" enough by it's inability to fly, does an occasional ride on a glider make up for the hours/days/weeks/months/years of doing nothing but sitting on a perch? Again, I don't attribute the emotion of "upset" to these birds... To be fair, roughly 65% of the birds I later release "should" fall into the "less fit" bracket, by odds. Even though they're of breeding age, will they breed? Will they make it an additional year on their own? Does it matter? I don't know... From what I know of these birds, hunting matters, since that's what they do. The flying part is just they way they travel. Flying isn't a novelty to them, like it is to us.
Two possible reasons for rehab come to mind. One, saving birds that are low in overall population to allow them to breed sounds good. Another would be to use them for educating the public. Bald eagles are no longer endangered, so I don't see the purpose in saving them to breed. I'm not really all that much in favor of using crippled birds as educational birds (for a few reasons), but I don't think completely healthy raptors should be kept as pets, or just for educational purposes either, so I make concessions there. I don't think the public learns more from a crippled raptor than from a healthy one. In actual practice, I can/could show them more with a healthy raptor.
So, when it comes to hang glider rides, I think it looks nice, and pulls at the heart-strings a little. But I think the bird gets nothing at all from it (but isn't hurt by it either). Doing it means something to the people who do it, and to the people that watch it. But, if the guy was only doing it for the bird, I don't see why he filmed it and posted it on the internet though, either, unless maybe he's trying to raise funds so he can buy some critters to feed the eagle with?
