Pete, Ann,
If you fancy wading through an academic paper, I've one to share with you (can't really post it here as that wouldn't be fair on the authors).
It was sent to me by an acquaintance at BirdLife Switzerland and it covers human feeding of raptors, particularly kites, and has some interesting insights.
"Friend me", or whatever it's called and I'll drop it into a message. Then, if you prefer, "unFriend me" (just like in real life ;-) ).
You may recall that in the past I mentioned a friend of ours who fed kites for decades. We used to watch the show morning and evening. Our best count was 11 Black and 2 Red (accompanied by a cheeky kestrel). Nelly's kite feeding days are over, sadly. But we'll be talking birds with her when we visit next week.
Here it's not uncommon to see large numbers of birds congregating (naturally, so to speak) on food sources. In the past we've counted a mixed group of over 40 mixed kites in a small area of cultivated agricultural land.
They are, indeed, very beautiful birds. And while (for me, at least) they're easy to ID once you're used to them, they do show a surprising amount of variation in flight modes and shapes, which also helps to keep one on one's toes when there are other big birds up.
Dave